How To Select Your Soil Lab

By Susan Shaner

Soil lab selection: How does anyone choose the right laboratory? Aren’t they all the same? Should you send a sample to several different labs and average the results? How do you get the samples to a lab and what is the turnaround time? Some homework needs to be done here.

These are all questions that I hear on almost a daily basis. All labs are not the same. This does not mean that one laboratory is better than another. They all provide a different “menu” of services. It is important to find a lab that provides all of the services that you require. Are you just looking for a soil analysis, or do you also need an irrigation water test or tissue analysis?

Laboratories can also choose from a number of methods or “recipes” to obtain results. Which method would be best for your soil type or crop? “Presentation” of results can also vary greatly from one laboratory to another. It is important that you can read the report and make use of the information it provides. These are all questions that you should consider before choosing a laboratory.

Menu of Services

Packages with various soil parameters are usually available, plus some a la carte choices. This will vary greatly from one laboratory to another. I think we all agree now that there is a lot more to soil than pH. Therefore, look at what is included in the soil package you are requesting.

soil sample

Important parameters include pH, organic matter, exchange capacity and base saturation. Also important are the major elements calcium, magnesium, potassium, sodium and phosphorus.

Important minor elements include sulfur, boron, iron, manganese, copper, zinc and aluminum. A complete soil analysis including all of these parameters may cost a little more. More information will provide better insight into your fertility situation. If you base your decision on cost alone, you will probably get what you pay for. An inexpensive analysis may only include pH, phosphorus and potassium.


Methodology is the most confusing area when comparing laboratories. There are several different methods for almost every parameter on a soil analysis. Laboratories choose methods that are best suited for the geographical area that they service. Most labs will offer different methods upon request to accommodate most customers; you will have to know what to request first.

Sending the same sample to several labs for comparison will be quite confusing unless you do your homework to determine what methods are used. I have talked with several customers after they have submitted the same sample to different labs without understanding the differences.

They have been very unhappy and disappointed with the outcome. Let’s look at a good example of different methods — for example, phosphorus. There are nine phosphorus test methods that I am aware of. All of these methods were run on a specific soil sample and produced results anywhere from 10.5 to 656 ppm. If you know how to interpret the results for each of these tests, you should come up with the same recommendation. If you do not have the correct threshold levels for the method provided, you could make a big mistake in interpretation.

Presentation of Data

What units of measure do you feel comfortable with? Do you prefer graphic results, high and low distinctions or an actual value found?

Soil reports come in all shapes and sizes. Some reports are very colorful and show your results in a graphic form. Various reports show values as low, adequate, or high. A number of reports show actual values found for each parameter. Reporting styles also vary regarding the reporting of desired levels, sufficiency levels and base saturation percentages. What style are you most comfortable with? A combination of these styles may be most helpful.

Units of measure can vary from parts per million, pounds per acre, pounds per 1,000 square feet, or kilograms per hectare.

It is very important that the laboratory is aware of your sampling depth if you will be receiving your results in a pound per acre or pound per 1,000 square feet format. The sampling depth will affect the value reported. It is vital to be aware of units when comparing reports from different laboratories. You have to compare apples to apples. Looking at a phosphorus example again will explain this. A laboratory may report phosphorus at 50 ppm P and another may report it at 229 pounds per acre P2O5. These two results are the same; however the units are the difference.

Does the soil report offer a recommendation? Where did it come from? Some recommendations are generic computer recommendations that give a ballpark range for optimum levels of nutrients. These may or may not be for a specific geographical area. If you are growing a unique or exotic crop, then you may need some specific advice. Inquire about the services of an independent agronomist.


How do you get your sample to the lab? Most labs will provide a soil sample bag or suggest a suitable alternative. Soil laboratories receive hundreds of samples each day. Be sure to acquire the appropriate paperwork from the laboratory to submit with your sample. Incomplete information will only delay the processing of your samples. Packing your samples for shipment is very important. Be sure to pack the samples tightly in a box. Pack newspaper or other packing material around the samples to keep them from bouncing around in the box.

If samples can move around during shipment, they sometimes break open and can be destroyed. Resampling will add to your cost in time and money.

How long will this process take? Turnaround time in the whole soil testing process is imperative. Laboratories under stand that your test results can be time sensitive. Don’t hesitate to contact the lab if you have an emergency situation and need “rush” service. To determine your approximate turnaround time, consider the time it takes to get the sample to the lab (two-three days) and perform the analysis (three-four days).

Turnaround time varies from one lab to another and also varies by season. You may want to contact the lab to inquire about their current turnaround time. How do you get your report? You do not want the report held up somewhere after you have already waited through shipping and testing procedures. Reports are usually emailed or made available on the internet on the same day the testing is completed. Be sure your correct email address and/or a fax number is submitted with your samples to get your results as soon as possible.

This is just the tip of the iceberg when looking at differences in laboratories. Laboratory instrumentation is continually improving. More parameters can be detected in a short amount of time and detection limits keep getting smaller. More efficient and “green” procedures are always being investigated.

Embrace the advancements. Visionaries like Dr. Albrecht are still being cited in soil analysis circles. If he was continuing his research today, I believe he would embrace the latest technology and tools available.

So, the question still looms … which laboratory is best for you? Take the time to do your homework. It will be worth the investment and you will receive the value that you expect. Explore laboratory websites, call a lab and ask some questions, ask your friends about their experiences. Make sure you acquire the appropriate paperwork and instructions from the lab that you choose.

When you have selected a laboratory that meets your needs and you are comfortable, stick with it. Jumping from lab to lab will only discourage you on your quest to improving soil fertility.

Editor’s Note: This article appeared in the October 2011 issue of Acres U.S.A.

Increasing Soil Organic Matter Through Organic Agriculture

By André Leu

Numerous scientific studies show that soil organic matter provides many benefits for building soil health such as improv­ing the number and biodiversity of beneficial microorganisms that pro­vide nutrients for plants, including fixing nitrogen, as well as controlling soilborne plant diseases. The decom­position of plant and animal residues into SOM can provide all the nutri­ents needed by plants and negate the need for synthetic chemical fertilizers, especially nitrogen fertilizers that are responsible for numerous environ­mental problems.

The year 2015 was declared the International Year of Soils by the 68th UN General Assembly with the theme “Healthy Soils for a Healthy Life.” I was particularly pleased with the theme because this is a message that we in the organic sector have been spreading for more than 70 years, and at first we were ridiculed. Now there is a huge body of science showing that what we observed in our farming systems is indeed correct.

“Organic farming” became the dominant name in English-speaking countries for farming systems that eschew toxic, synthetic pesticides and fertilizers through J.I. Rodale’s global magazine Organic Farming and Gar­dening, first published in the United States in the 1940s. Rodale promot­ed this term based on building soil health by the recycling of organic matter through composts, green ma­nures, mulches and cover crops to increase the levels of soil organic matter as one of the primary management techniques.

organic field
Organic vs. Conventional. The higher levels of organic matter allow the soil in the organic field to resist erosion in heavy rain events and capture more water.
Water run-off

Soil organic matter improves soil structure so that it is more resistant to erosion and is easier to till, resulting in lower energy use and less greenhouse gas output. Soils with good SOM levels are more efficient at absorbing rain­water and storing it for plants to use in dry periods. Studies show that organic systems get around 30 percent higher yields in periods of drought than con­ventional systems due to the increase of SOM and its ability to capture and store water for crops.

SOM is composed largely of car­bon that is captured as CO2 from the air by plants through photosynthe­sis. Published, peer-reviewed meta-studies show that organic farming systems are superior to conventional systems in capturing CO2 from the atmosphere (the primary greenhouse gas responsible for climate change) and sequestering it into the ground as SOM.

Soil Organic Matter & Climate Change

Worldwide, agriculture is respon­sible for between 11 and 30 percent of greenhouse gas emissions, depending on the boundaries and methodolo­gies used to determine its emissions. According to the United Nations En­vironment Programme, the estimates of global greenhouse gas emissions in 2010 were 50.1 gigatons of carbon di­oxide equivalent (Gt CO2e) per year. To keep global mean temperature increases below 2°C compared to pre-industrial levels, GHG emissions will have to be reduced to a median level of 44 Gt CO2e in 2020.

This means that the world will have to reduce the current level of emissions by 6.1 Gt CO2e by 2020 and reduce it every subsequent year. According to the latest World Me­teorological Organization figures, the levels of GHG pollution in the atmosphere and the oceans are the highest in history and are still increasing.

Keeping the rise in temperature below 2°C will not only involve re­ducing emissions through energy effi­ciency, renewable energy and cleaner energy sources; sequestering GHGs already present in the atmosphere will also be necessary to reduce the current levels. Currently most seques­tration is based on growing biomass as carbon sinks and capturing it as wood-based products.

Soils are the greatest carbon sink after the oceans. According to Profes­sor Rattan Lal of Ohio State Univer­sity, there are over 2,700 Gt of carbon stored in soils worldwide. This is considerably more than the combined total of 780 Gt in the atmosphere and the 575 Gt in biomass.

The amount of CO2 in the oceans is already causing problems, particu­larly for species with calcium exo­skeletons such as coral. Scientists are concerned that the increase in acid­ity caused by higher levels of CO2 is damaging these species and threatens the future of marine ecosystems such as the Great Barrier Reef.

Mitigation Through Aboveground Biomass

Currently the major push for car­bon sequestration is through above-ground biomass, despite that fact that its potential as a carbon sink is signifi­cantly less than that of soil. The other issue is the need to take land out of food production to grow trees. There is some potential with agroforestry and trees as shade cover for some cash crops like coffee and cacao, however this will deliver considerably less than research has shown can be sequestered into soils with good agri­cultural practices.

Sequestration Through Agriculture 

The ability of soils to absorb enough CO2 in order to stabilize cur­rent atmospheric CO2 levels is a criti­cal issue, and there is a major debate over whether this can be achieved through farming practices. Reviews of conventional farming systems have found that most are losing soil car­bon and at best they can only slow the rate of loss. On the other hand, farming systems that recycle organic matter and use crop rotations can increase the levels of soil organic car­bon (SOC).

A preliminary study by the Re­search Institute of Organic Agricul­ture, Switzerland, published by FAO, collated 45 comparison trials between organic and conventional systems that included 280 data sets. These studies included data from grasslands, arable crops and permanent crops in several continents. A simple analysis of the data shows that on average the or­ganic systems had higher levels of soil carbon sequestration.

Dr. Andreas Gattinger and col­leagues wrote, “In soils under organic management, the SOC stocks aver­aged 37.4 tons C ha-1, in comparison to 26.7 tons C ha-1 under non-organic management.”

This means that the average differ­ence between the two management systems (organic and conventional) was 10.7 tons of C. Using the accepted formula that SOC x 3.67 = CO2, this means an average of more than 39.269 tons of CO2 was sequestered in the organic system than in the con­ventional system.

The average duration of manage­ment of all included studies was 16.7 years. This means that an average of 2,351 kg of CO2 was sequestered per hectare every year in the organic sys­tems compared to the conventional systems.

In a later peer-reviewed meta-anal­ysis, published in PNAS, that used 41 comparison trials and removed the outliers in the data sets in order not to overestimate the data and to obtain a conservative estimate, researchers reported that organic systems seques­tered 550 kg C per hectare per year. This equates to 2018.5 kg CO2 per hectare per year.

Based on these figures, the wide­spread adoption of current organic practices has the potential to sequester around 10 Gt of CO2, which is the range of the emissions gap in 2020 of 8-12 Gt CO2e per year.

The potential exists for higher lev­els of CO2 sequestration. All data sets that use averaging have outlying data. These are examples that are sig­nificantly higher or significantly lower than the average.

There are several examples of higher levels of carbon sequestra­tion than the averages quoted in the studies above. The Rodale Institute in Pennsylvania has been conducting long-running comparisons of organic and conventional cropping systems for more than 30 years that confirm organic methods are effective at re­moving CO2 from the atmosphere and fixing it as organic matter in the soil. Tim LaSalle and Paul Hepperly wrote, “In the FST [Rodale Institute farm systems trial] organic plots, car­bon was sequestered into the soil at the rate of 875 lbs/ac/year in a crop rotation utilizing raw manure, and at a rate of about 500 lbs/ac/year in a rota­tion using legume cover crops.

During the 1990s, results from the Compost Utilization Trial (CUT) at Rodale Institute — a 10-year study comparing the use of composts, ma­nures and synthetic chemical fertil­izer — show that the use of composted manure with crop rotations in organic systems can result in carbon seques­tration of up to 2,000 lbs/ac/year. By contrast, fields under standard tillage relying on chemical fertilizers lost almost 300 pounds of carbon per acre per year.”

Converting these figures into kilo­grams of CO2 sequestered per hectare using the accepted conversion rate of 1 pound per acre = 1.12085116 kg/ ha and SOC x 3.67= CO2, gives the following results: The FST legume-based organic plots showed that car­bon was sequestered into the soil at the rate of about 500 lbs/ac/year. This is equivalent to a sequestration rate of 2,055.2kg of CO2/ha/yr, which is close to the average found in the Gat­tinger meta-study.

However, other organic systems produced much higher rates of se­questration. The FST manured or­ganic plots showed that carbon was sequestered into the soil at the rate of 875 lbs/ac/year. This is equivalent to a sequestration rate of 3,596.6 kg of CO2/ha/year and if extrapolated globally would sequester 17.5 Gt of CO2.

The CUT showed that carbon was sequestered into the soil at the rate of 2,000 lbs/ac/year. This is equivalent to a sequestration rate of 8,220.8 kg of CO2/ha/year and if extrapolated globally, would sequester 40 Gt of CO2.

A meta-analysis by Eduardo Agu­ilera et al. published in the peer-re­viewed journal, Agriculture, Ecosystems and Environment, of 24 comparison trials in Mediterranean climates be­tween organic systems and non-or­ganic systems without organic supple­ments found that the organic systems sequestered 970 kg of C/ha/year more than the non-organic systems. This equates to 3559.9 kg of CO2/ha/year. The data came from comparison trials from Mediterranean climates in Eu­rope, the United States and Australia, and if extrapolated globally, would sequester 17.4 Gt of CO2.

The Louis Bolk Institute conducted a study to calculate soil carbon seques­tration at SEKEM, the oldest organic farm in Egypt. Their results show that on average SEKEM’s management practices resulted in 900 kg of carbon being stored in the soil per hectare per year in the fields that were 30 years old. Using the accepted formula of SOC x 3.67 = CO2, this means that SEKEM has sequestered 3,303 kg of CO2 per hectare per year for 30 years.

Based on these figures, the adop­tion of SEKEM’s practices globally has the potential to sequester 16 Gt of CO2, which is around 30 percent of the world’s current GHG emission into soils.

It is not the intention of this paper to use the above types of generic exercises of globally extrapolating data as scientific proof of what can be achieved by scaling up organic systems. These types of very simple analyses are useful for providing a conceptual idea of the considerable potential of organic farming to reduce GHG emissions on a landscape scale. The critical issue here is that urgent peer-reviewed research is needed to understand how and why — and for the skeptics, if — these systems seques­ter significant levels of CO2 and then look at how to apply the findings for scaling up on a global level in order to achieve GHG mitigation.

Greater Resilience in Adverse Conditions 

According to research by the UN­FCCC IPCC Fourth Assessment Re­port (IPCC 2007) and others, the world is seeing increases in the fre­quency of extreme weather events such as droughts and heavy rainfall. Even if the world stopped polluting the planet with greenhouse gases to­morrow, it would take many decades to reverse climate change. This means that farmers have to adapt to the increasing intensity and frequency of adverse and extreme weather events.

organic vs conventional fields
From The Rodale Institute: Organic vs. Conventional fields side by side.

Published studies show that organic farming systems are more resilient to predicted weather extremes and can produce higher yields than conven­tional farming systems in such con­ditions. For instance, the Wisconsin Integrated Cropping Systems Trials found that organic yields were higher in drought years and the same as con­ventional in normal weather years.

Improved Water Use Efficiency 

Research shows that organic sys­tems use water more efficiently due to better soil structure and higher levels of humus and other organic matter compounds. D.W. Lotter and col­leagues collected data over 10 years during the Rodale Farm Systems Trial. Their research showed that the organ­ic manure system and organic legume system (LEG) treatments improve the soils’ water-holding capacity, infiltra­tion rate and water capture efficiency. The LEG maize soils averaged 13 percent higher water content than conventional system (CNV) soils at the same crop stage and 7 percent higher than CNV soils in soybean plots. The more porous structure of organically treated soil allows rain­water to quickly penetrate the soil, resulting in less water loss from runoff and higher levels of water capture. This was particularly evident during the two days of torrential downpours from hurricane Floyd in September 1999, when the organic systems cap­tured around double the water as the conventional systems.

Long-term scientific trials con­ducted by the Research Institute of Organic Agriculture in Switzerland comparing organic, biodynamic and conventional systems had similar re­sults showing that organic systems were more resistant to erosion and better at capturing water.

“We compare the long-term effects (since 1948) of organic and conven­tional farming on selected properties of the same soil. The organically farmed soil had significantly higher organic matter content, thicker topsoil depth, higher polysaccharide content, lower modulus of rupture and less soil erosion than the conventionally-farmed soil. This study indicates that, in the long term, the organic farming system was more effective than the conventional farming system in re­ducing soil erosion and, therefore, in maintaining soil productivity (Regan­old et al. 1987).”

Humus, a key component of SOM, allows for the ability of organic soils to be more stable and to hold more water. This is due to its ability to hold up to 30 times its own weight in water, and being a ‘sticky’ polymer, glues the soil particles together, giving greater resistance to water and wind erosion.

There is a strong relationship be­tween SOM levels and the amount of water that can be stored in the root zone. The table below should be taken as a rule of thumb, rather than as a precise set of measurements. Different soil types will hold different volumes of water when they have the same levels of organic matter due to pore spaces, specific soil density and a range of other variables. Sandy soils generally hold less water than clay soils.

The table above gives an under­standing of the potential amount of water that can be captured from rain and stored at the root zone in relation to the percentage of SOM.

There is a large difference in the amount of rainfall that can be captured and stored between the current SOM level in most traditional farms in Asia and Africa and a good organic farm with reasonable SOM levels. This is one of the reasons why organic farms do better in times of low rainfall and drought.

The Rodale Farming Systems Trial showed that the organic systems produced more corn than the conventional system in drought years. The average corn yields during the drought years were 28 to 34 percent higher in the two organic systems. The yields were 6,938 and 7,235 kg per ha in the organic animal and organic legume systems, respectively, compared with 5,333 kg per ha in the conventional system. The researchers attributed the higher yields in the dry years to the ability of the soils on organic farms to better absorb rainfall. This is due to the higher levels of organic carbon in those soils, which makes them more friable and better able to capture and store rainwater which can then be used for crops.

This is very significant information as the majority of the world’s farming systems are rain-fed. The world does not have the resources to irrigate all of the agricultural lands, nor should such a project be undertaken. Improving the efficiency of rain-fed agricultural systems through organic practices is the most efficient, cost-effective, environmentally sustainable and practical solution to ensure reliable food production in the face of increasing weather extremes.

Synthetic Nitrogen Fertilizers 

One of the main reasons for the differences in soil carbon between organic and conventional systems is that synthetic nitrogen fertilizers de­grade soil carbon. Research shows a direct link between the application of synthetic nitrogenous fertilizers and decline in soil carbon.

Scientists from the University of Il­linois analyzed the results of a 50-year agricultural trial and found that syn­thetic nitrogen fertilizer resulted in all the carbon residues from the crop disappearing as well as an average loss of around 10,000 kg of carbon per hectare per year. This is around 36,700 kg of CO2 per hectare on top of the many thousands of kilograms of crop residue that is converted into CO2 every year.

Researchers found that the higher the application of synthetic nitrogen fertilizer the greater the amount of soil carbon lost as CO2. This is one of the major reasons why most conventional agricultural systems have a decline in soil carbon while most organic sys­tems increase soil carbon.

Plant-Available Nitrogen Levels

One of the main concerns about organic agriculture is how to get suf­ficient plant-available nitrogen with­out using synthetic nitrogen fertilizers such as urea.

SOM, particularly the humus frac­tions, tend to have a carbon nitrogen ratio of 9:1 to 11:1. As the carbon levels increase, the amount of soil ni­trogen increases in order to maintain the carbon-nitrogen ratios. Adding organic matter into the soil to increase carbon, results in the nitrogen levels increasing.

organic nitrogen in soil amounts
Table: amount of organic nitrogen held in soil.

Much of this soil nitrogen is fixed by free-living soil microorganisms such as azobacters and cyanobacte­rias. The use of DNA sequencing is revealing that cohorts of numerous thousands of species of free-living microorganisms are involved in fix­ing nitrogen from the air into plant available forms. There are many stud­ies that show that there is a strong relationship between higher levels of SOM and higher levels of soil biologi­cal activity.

This biological activity includes free-living nitrogen-fixers, and they turn the atmospheric nitrogen, the gas that makes up 78 percent of the air, into the forms that are needed by plants. They do this at no cost and are a major source of plant-available nitrogen that is continuously over­looked in most agronomy texts.

New research has found a new group of nitrogen-fixing organisms called endophytic microorganisms. These microbes can colonize the roots of numerous plant species including rice, grain crops and sugar cane.

Soil Carbon, Nitrogen Ratios 

It is important to get an understanding of the potential for how much nitrogen can be stored in SOM for the crop to use. SOM contains nitrogen expressed in a Carbon to Nitrogen Ratio. This is usually in ratios from 11:1 to 9:1; however, there can be further variations. The only way to firmly establish the ratio for any soil is to do a soil test and measure the amounts.

For the sake of explaining the amount of organic nitrogen in the soil we will use a ratio of 10:1 to make the calculations easier.

The amount of carbon in SOM is expressed as SOC and is usually measured as the number of grams of carbon per kilogram of soil. Most texts will express this as a percentage of the soil to a certain depth. There is an accepted approximation ratio for the amount of soil organic carbon in soil organic matter: SOC × 1.72 = SOM.

The issue of working out the amount of SOC as a percentage of the soil by weight is complex as the specific density of the soil has to be factored in because some types of soils are denser and therefore heavier than other soils. This will change the weight of carbon as a percentage of the soil.

To make these concepts readily understandable we will use an average estimation developed by Dr. Christine Jones, one of Australia’s leading soil scientists and soil carbon specialists. According to Dr. Jones: “… a 1 percent increase in organic carbon in the top 20 cm of soil represents a 24 t/ha [24,000 kg] increase in SOC …”

This means that a soil with 1 percent SOC would contain 24,000 kg of carbon per hectare. With a 10:1 carbon to nitrogen ratio this soil would contain 2,400 kg of organic nitrogen per hectare in the top 20 centimeters, the primary root zone.

The conventional dogma around nitrogen is that it can only be used by plants if it is in the form of nitrate or ammonium and that organic nitrogen is mostly not available to the crop until it has been converted into these two forms of N.

There are hundreds of peer-reviewed scientific studies that show that this assumption is incorrect and that in natural systems plants take up nitrogen in numerous organic forms such as amino acids, amino acid precursors and DNA.

The fact is that the significant proportion of the organic nitrogen in the soil is readily available to the crop. The key to get an adequate level of N is to increase SOM levels rather than adding synthetic nitrogen fertilizers.

Given that synthetic nitrogen destroys organic matter, the use of these fertilizers should be avoided as they lock farmers into a perpetual dependence on these costly inputs once the organic matter levels have been run down and most of the organic nitrogen forms in the soil have been depleted. Farmers should be encouraged to obtain all their nitrogen from organic sources such as composts, manures, green manures and legumes and build up their organic matter levels.

By André Leu. This article appeared in the July 2015 issue of Acres U.S.A.

André Leu is the author of Poisoning our Children and The Myths of Safe Pesticides. He is the International Director of Regeneration International.

A Guide to Reading Soil Test Results

By Charles Walters

What is a Soil Test?

A reliable soil test includes three parts:

  • Proper sampling, with field and cropping history, and yield goals.
  • Chemical tests for nutrients available for crop growth.
  • Reliable recommendations for nutrients and amendments needed to attain desired yield goals.
Klaas Martens: Soil, Testing & Fertility from the 2009 Eco-Ag Conference & Trade Show. Listen in as the popular agronomist and successful organic farmer teaches his methods for managing soil testing, data and inputs.

Reading a Soil Test

The following is how laboratory results are reported at Texas Plant & Soil Lab — other labs utilize similar terms.

Texture — Ranges from 1 (sand) to 3 (loam) to 6 (heavy clay)

Cation Exchange Capacity (CEC) — Texture determines the CEC. Textures of 1 = 3-8 CEC. Textures of 6 = 30-50 CEC.

Organic Matter (O.M.) — Humus increases CEC. About 3.5 CEC increase for each percent increase in humus. O.M. improves tilth (soil physical condition), water and nutrient holding capacity. The more the better. Ideal O.M. levels for corresponding texture levels (1-6 respectively) = 2.8, 3.1, 3.6, 4.1, 4.5, 4.8.

Natural Extracting (CO2) — Plants produce natural carbonic acid in the root zone which can be used to obtain nutrient values that are more realistic and calibrates to the plant uptake.

NO3 (N) — This highly soluble nitrate ion moves easily up and down with water and is a constantly changing value. Plant uptake is rapid. Excess can be toxic.

P2O5 (P) — Extracted with CO2, the amount is reported in pounds per acre for the top foot of soil. The amount reported is available to a crop in a normal growing season. Responses can be expected below 40 pounds per acre and high phosphorus requiring crops may respond to additional phosphate of up to a 200 pounds per acre tested.

Potassium (K) — Extractable using CO2. This is the amount available to the crop in a growing season. Readings range from of 80 ppm to 120 ppm for crops with high potash needs. Soil availabilities vary with texture, soil moisture conditions, interference from sodium levels and ratios of Na, Ca and Mg.

pH — The acidity measurement is variable. Most crops prefer a pH between 6.5 and 7.3. Neutral is 7.0, above is alkaline and below is acid. The desirable pH level is a nebulous, dynamic determination that is highly variable.

Electrical Conductivity (EC) Salts — This is a measure of total water-soluble salts expressed as mmhos/cm. EC x 640 = total dissolved solids in ppm.

Salt Cations — Water-soluble cations determined by the atomic absorption spectrophotometer. Calcium is important and should exceed 100 ppm.

CO2 extractable (carbonic acid equivalent) is the same as the plant root process. Sodium is the main extractable harmful element and should be below 180 ppm. The amount of extractable calcium reserve in the soil is also reported and must be known to properly manage excess salts.

Na (CO2)/Ca (H2O) and Na (CO2)/Mg (H2O) — These ratios help evaluate salt problems and are indicators of the soil’s physical con­dition for water, air and root penetration. The Na:Ca ratio should be less than 6 for good internal drainage. The Na:Mg ratio should be below 20 for regular crops and below 10 for sugar-producing crops such as melons, citrus, sugarcane, etc.

Source: Ask the Plant

Examples of How to Adjust to Your Soil Test Results

By Neal Kinsey

Reading your soil test and knowing what to do are two different things. Here are some examples of how to apply results to your fields based on what your soil test is indicating. It will give you confidence that you are on the right track to increasing your overall soil health.

Except in the case of wheat and other small grains, if the soil test indicates that you need ten pounds of copper sulfate but that amount represents a cost that is too high, you could consider putting on two pounds for the next five years instead of ten pounds all at once. You can build copper levels this way because that nutrient is so stable in the soil. Almost every soil analyzed is deficient in copper. The few exceptions are where there is natu­rally occurring copper in the soil or where manure has been used, or along rivers where soil has been moved in by constant flooding, and where alluvial deposits keep the soil built up. The other place where we don’t have copper deficiencies is where large amounts of pesticides containing copper have been used in the past, and where turkey litter is commonly used.

When crops on soils with adequate fertility that test low in copper fail to respond to copper applications, a molybdenum test should be considered. Both need to be present in adequate amounts, since either one can influence the amount a crop can take up of the other one.

A farmer from Iowa I had worked with for eight years called me one day. He said he had a problem with some of his corn going down. He wanted me to look at the soil test. He had 80 acres split into four 20s, and one had a 1.5 copper, his lowest level. I told him that his copper was 1.5 ppm and he was going to have the weakest stalks there. It was true. He said, “Well, since that is true, what about the next field?” We went through all the data until he hit 2 ppm. In each case he lost corn from lodging, but the lower the copper level below 2 ppm, the worse the corn was lodged.

Copper gives resilience to a plant. The other key to flavor after sulfur is copper. Copper doesn’t move in the soil. If you see a copper deficiency at all, it is like sulfur. It shows the deficiency in the young­est growth first. Adequate nitrogen means you get better copper uptake. Too much nitrogen means you actually decrease the avail­ability of copper to the plant. Wheat is a crop that responds well to copper. If the other needed nutrients are adequate, but you are below 2 ppm copper and you put enough copper on your wheat to get above 2 ppm, it will produce an extra five bushels (300 pounds/acre) of wheat.

I was asked to make a consulting trip to Germany in 1985. The client who asked me there had arranged for speaking engagements to several groups of farmers. He told me to tell them just what I had done on his farms. In Germany, they use the taller varieties of wheat, but they also use growth regulators to keep plants short. When the subject turned to copper, I mentioned that if the soil had below 2 ppm and copper was put on, it would increase yields by five bushels per acre. I also told them that every soil I had checked in Germany was below that level. One man raised his hand, stood up and spoke for two or three minutes. The interpreter leaned over and said, “This is the man who is in charge of fertility for the university in this area. He is telling the farmers why they don’t need to really worry about the copper that you said should be put on.” When he had finished, a doctor of fertility research rose and reported a ten-year study (unknown to me) just completed which had shown exactly the same results I had mentioned on wheat production.

Copper sulfate, 22.5 or 23 percent, is water-soluble and can be applied to soil or as a foliar. A word of caution here. When cop­per is mixed in solution with other elements it may show as compatible in the mix, but use it up. Do not let it set in your spray tank, pumps or hoses overnight. It can harden to the point that the entire spraying apparatus has to be scrapped. I won’t bother with other copper sources if I can get copper sulfate because I know it works, and I know how much can be applied safely. A ten-pound application of copper sulfate—after 12 months time—will raise the copper level by 0.6 ppm on the spe­cific test we use. A copper level is the easiest to build and main­tain, and zinc is next in the pecking order. Both have staying power in the soil.

Zinc aids in the absorption of moisture. Along with potassium, think of zinc in critical moisture situations. It also helps transform carbohydrates. It regulates plant sugar use. Zinc plays a role in enzyme system functioning, as well as with the growth regulators normally present in the plant and protein synthesis.

Consider zinc needs, especially in sensitive crops such as corn and grain sorghum, also soybeans and dry beans. As far as zinc levels are concerned, the minimum is 6 ppm. Below that, enough should be applied the first year to get up above the 6 ppm figure. There has never been a soil—in my experience at least—that required more than 30 pounds of zinc sulfate to completely take care of the worst zinc deficiency, provided limestone didn’t have to be applied at the same time. If lime is applied, the lime won’t drive out the zinc, but it will affect zinc availability. If you need zinc and lime and put on the lime but don’t put on the zinc, expect your zinc level to get worse. Zinc probably gives a response more often than any other micronutrient when it is applied for crop production. I see many soils that need zinc. All can be taken care of, generally with excellent response. Only a few crops do not respond well to zinc when only slightly deficient, one of them being wheat. Again, for zinc, 6 ppm is the minimum. Excellent means at least 10 ppm, and an excess is 35+ ppm.

A classic sign of zinc deficiency in corn is the whitish stripe in the leaf color, which looks much like a magnesium deficiency. In the field, often I can’t tell whether it is a zinc deficiency or a magnesium deficiency. The difference between zinc and magne­sium deficiencies should be that zinc will be white and magne­sium will be white on top with a purplish color on the bottom.

High phosphorous, high calcium or high potassium levels can induce zinc deficiencies as does the overuse of nitrogen. Also, as the pH goes up from 6, when a soil has good zinc levels, availability begins to decrease. It can go as high as pH 7 before it decreases good zinc availability to the point that it becomes a problem. Heavy cuts, such as when the field has been graded or the topsoil has been taken away, or when eroded soil allows sub­soils to appear, strong zinc deficiencies become evident.

Zinc is not easy to leach away. It is held well on clay and humus. Once zinc levels are improved, it is relatively easy to keep them up. When zinc sulfate is applied on the tests we have, an exact relationship between the amount of zinc applied and the increase shown on the soil test can be expected. Using 36% zinc sulfate at an application of 10 pounds per acre will exhibit a 3.6-pound increase of zinc on the test. The correlation is classic. Putting on ten pounds of 36% zinc sulfate means putting on 3.6 pounds of zinc per acre. A soil test — when the zinc is finished breaking down — should show an increase of 3.6 pounds of zinc. That translates into 1.8 ppm, meaning every 10 pounds of zinc sulfate applied will raise the zinc level by 1.8 ppm. There is one other thing to be remembered about pure zinc sulfate. Put on ten pounds of zinc sulfate today, then come back next year and pull a soil test on the same day. That zinc is only going to be halfway to its final level. You are only going to see a 0.9 ppm increase in the soil. When you put on sufficient zinc it will not reach the desired level for two years, but will supply enough zinc for the crops grown for both years.

Some firms say they have a 36% zinc product, it being a 36% oxysulfate. It is cheaper at the counter, but it does not always build zinc levels. There are some zinc oxide products that have been pulverized and then prilled, which have also proved effec­tive for increasing the levels in the soil. Apply ten pounds, the same as with 36% zinc sulfate, and see if next year the deficiency is still there. Pure zinc sulfate is the sure choice.

With the exception of boron, on most soils the technology exists in order to build the levels of trace elements to a point that it is not an annual expense, but basically an initial expenditure. Then afterwards, it is a matter of testing and fertilizing as need­ed over the years to keep the levels up. Many farmers, ranchers and growers initially resist the addition of trace elements to increase fertility levels, objecting to the added expense. But when you consider the years spent taking from the soil without adding the traces back, replenishing should be expected. And supplying those micronutrients have helped increase corn yields by 20-30 bushels, and wheat from 5-25 bushels per acre. Micronutrients, when applied in the right form, to build up the levels in the soil will help quality and crop yields accordingly.

Some farmers who have livestock have always felt they shouldn’t have to be concerned with trace elements because their manure or compost would take care of it. I work with many farmers who use manures and compost, and this is rarely the case. Think about it. When a soil is deficient in copper and adequate copper is not being supplemented, how can enough be in the manure? Manure is generally low in sulfur, boron and copper—the nutrients most often lacking in our soils used for growing the crops. Keep in mind, when manure is applied, you can influence the soil nutrient level to only the extent of what is there in the first place. Nevertheless, manure is certainly helpful and in certain soils even sufficient to keep the trace elements that are present in a soil most available for plant use, while at the same time helping to recycle those that are picked up in the feed. And therefore, as the use of manures in an area declines, the need for trace elements will increase.

Most soils we analyze just do not have an adequate supply of trace elements to assure that the crop will do its best. So keep in mind that just because there are enough of the major elements for the crop, does not assure that trace element levels will also be adequate.

Under the present economic circumstances, every farmer needs to have the confidence that he is on a solid footing, and doing all he can to supply his crops the fertility needed from start to finish. The misconceptions and misunderstandings about soil fertility make this even harder to accomplish. The more farmers or those involved in a soil fertility program understand the reasons behind micronutrient recommenda­tions, the more confidence there will be in those recommenda­tions and the decisions made on how to use them. The lack of any nutrient, whether needed in major, secondary or trace amounts, hurts the soil and all that must live from it.

Source: Hands-On Agronomy

Quest for Quality: Growing Nutrient-Dense Crops

By Leigh Glenn

For Central Virginia farmers Dan Gagnon and Susan Hill, the best proof that they’re doing things right with their soil to produce nutrient-dense crops comes from the mouths of babes and customers facing health challenges.

Gagnon and his wife, Janet Aardema, operate Broadfork Farm in Chesterfield, Virginia. Gagnon likes to observe how children interact with food. His youngest son Beckett, 3, last winter used organic store-bought carrots to dip into salad dressing while Gagnon’s mom was looking after him. But he would not eat the carrots.

When she dropped him off, Gagnon had just dug some overwintered carrots. Despite a bit of dirt clinging to them, Beckett gobbled them up. “The feedback from customers that we continue to get has been very encouraging,” said Gagnon. “Also, a child’s palate is a great indicator of the quality of your produce.”

Hill, who grew up outside Helena, Montana — where, she says, if they didn’t grow it, they didn’t eat — cooks for a woman who has multiple sclerosis; another customer has cancer and another, Lyme disease.

Farmer and soil
Dan Gagnon discusses soil structure at Broadfork Farm in Chesterfield, Virginia.

“Now, people tell me they feel better when they eat my vegetables,” said Hill, who grows in four high tunnels year-round and in raised beds in Louisa, about a half-hour east of Charlottesville. They should feel better, she says, “because they’re getting nutrients they would not get anywhere else.” And that’s what excites her the most about adopting a nutrient-based, quality-focused approach to soil vitality.

At both Broadfork and Hill Farm, the quest for quality is the common denominator. That overarching goal holds promise for reversing a variety of problems that originate with agriculture, from ecosystem degradation to low or no profitability.

A workshop led by farmer and Bionutrient Food Association (BFA) Executive Director Dan Kittredge catalyzed a change in approach for both Gagnon and Hill. BFA is a membership-based, nonprofit educational and research-oriented organization based in Massachusetts with the mission of increasing quality in the food supply, that is, the flavor, aroma and nutritive value of food.

Through the “Principles of Biological Systems” course, Kittredge connects the dots between soil vitality, plant health and human nutrition while helping growers understand the dynamics of their soil and best practices to increase its vitality as demonstrated by markers such as the soil’s ability to hold nutrients and increased organic matter as well as Brix.

Based on soil tests, growers do this through a variety of methods, including cultural practices — such as proper hydration and soil temperature maintenance, minimal tillage, cover crops and crop rotation — and inputs, which range from rock dusts and sea minerals to compost, inoculants and foliar feeds.

When Nothing Grows Well

Kittredge, who grew up on an organic farm, and whose parents, Julie Rawson and Jack Kittredge, have been running the Northeast Organic Farming Association’s Massachusetts chapter since 1985 (Jack retired in 2015), became interested in biological management when he encountered significant pest and disease pressure and saw how these were the key challenge to his ability to make a living farming.

Organic farm
Dan Gagnon prepares new ground at Broadfork Farm.

He began broadly researching soil and agronomy and got some of his major insights into how to do a better job through the Acres U.S.A. community. His “Principles” workshop is a culmination and distillation of his ongoing learning and practice.

Gagnon and Aardema, who both majored in biology, had been gardening for well over a decade before they decided to get into the vegetable business. After a couple years of gearing up they are entering their eighth season selling produce via CSA, an on-site farm stand and at area physical and virtual farmers’ markets. Their farm’s growing space encompasses 1.5 acres near Aardema’s parents’ property, an area that was farmed in the Civil War era, but then allowed to revert to pines early in the last century. Gagnon and Aardema worked on clearing land, developing the gardens and building infrastructure.

Though they tested through the extension service initially, they did not act on the results. The soil — “I call it a sand pit,” says Janet — is sandy loam, 12 to 18 inches deep, over clay subsoil. Gagnon doesn’t know whether the pines acidified the soil or whether it was acidic already, and the pines took advantage of that. The initial test revealed a pH of 5 and a cation exchange capacity — the soil’s ability to hold nutrients — of 2. “So there was nothing there,” he says, “Nothing for nutrients to hold onto, so that’s the reason I think we saw abysmal failures.” Those failures included tomato plants that never made it to maturity and greens that were puny and ran out of energy.

At the time, the couple were in the Elaine Ingham/Soil Food Web camp and thought compost and compost tea would solve their problems. When that approach failed they sought other ways of managing, including Albrecht and soil-balancing techniques, Steve Solomon’s The Intelligent Gardener and then the BFA and Kittredge’s bionutrient crop production workshop in early 2015.

“There is so much information out there on how to amend one’s soil,” said Gagnon. “It can be very confusing if you explore the different ideological soil perspectives.”

Healthy soil with high CEC at Broadfork Farm.

That’s where Gagnon turned to his liberal arts biology background and decided to start testing in earnest and collecting data so that he could see which amendments were working for which crops. They continued to use compost and compost teas, and based on soil testing, began to balance the major cations — calcium, magnesium, phosphorus and potassium — and then micronutrients. The results: a rising pH level, cation exchange capacity in some places of 10 to 11, decreased disease pressure and predation, higher Brix numbers, better soil electrical conductivity and increased flavor.

“We’re seeing all of that,” he says. Something he learned from John Kempf of Advancing EcoAg and paraphrased speaks to this: “When we shoot for quality, yield and flavor — all of those get tagged along. When you just shoot for yield, you’re not necessarily going to get quality and flavor. If your goal is quality, you will get disease resistance, quality and yield.”

The 2017 growing season marked the first in which Gagnon and Aardema eased back on amending the soil for the longer-running beds, and Gagnon says he expects to begin to pay greater attention to nuanced practices, such as how to shift bacterial — or fungal-oriented soil populations depending on what kind of vegetable they’re growing — more bacterial for brassicas, say, and less disturbance and greater fungal populations for tomatoes and other nightshade-family plants.

Hill Farm

About an hour northwest of Broadfork Farm, in Louisa, Susan Hill gets that same kind of feedback children provide Aardema and Gagnon, only it’s coming from adults, such as  the woman for whom she cooks as well as members of her year-round CSA who notice a difference. Their Chesnok Red garlic was so large that she said some outlets she provides it to were not inclined to take it because people think it’s elephant garlic.

Hill and her husband, Scott, found their land in 1999 and he agreed to build her a high tunnel if she would leave her teaching job and become a grower. Scott helps pick tomatoes and monitors and adjusts the sophisticated watering system, and Susan does everything else.

Susan Hill grows large Chesnok Red garlic at Hill Farm in Louisa, Virginia.

Hill says she got a lot out of Kittredge’s workshop, but didn’t apply everything all at once. She keeps careful records and likes to take a slow approach to see what works best where and with which crops. Last year marked her fourth year of “serious nutrient management.”

“When I first got into bionutrient growing, I got Azomite and I did a bed with Azomite — same plants, same original soil — and one without. I just began to experiment. Broad spectrum, I don’t think, is the way to go.” That means if a recipe calls for a quarter-pound of this or that, she won’t necessarily follow it.

“Certain plants need less of something and more of something else. I keep track of all beds, what I put in. If it’s a heavy-feeder brassica, then I’ll go back and add after they’ve been in because of what they feed on.” Growing under stressed conditions to begin with, she adds, there will be issues. The key is figuring out how to supply the plants with what they need so they can adapt and live out their full potential.

To Hill, serious nutrient management means going steady and carefully. She digs holes, puts in the nutrients — which ones depends on which crops she’s planned — dips the roots in compost/worm tea and sets the plants in. It’s an approach tailored to the plants. For example, with tomatoes, she feeds calcium and manganese once a week for the first month the plants are in to help them take up nutrients. As soon as they bloom she stops and switches to SEA-90 — a seawater-based mineral and trace fertilizer.

They don’t need anything else, she says. The proof that it works: In 2017’s challenging drought, the tomatoes were still going in late August. The Hills were the only ones in their neighborhood to have tomatoes, and they had no disease pressure, such as early blight.

Outside the high tunnels, where Hill had rows of tomatoes that had been giving fruit since May, they planned to pull back the high-quality plastic, plant a cover crop, cut it and not till it in and then cover the area again with the plastic. Hill says that allows the cover crop to, in essence, soak in, saves weeding and protects the soil, keeping the moisture in for earthworms when it’s hot. Though the land had been planted in tobacco, she now has 5 to 6 inches of “beautiful soil.”

organic garden
Eggplant going strong in August in a high tunnel at Hill Farm.

As precise as Hill is with her measurements, tests and crop records, she also leaves things that other growers might pull out, such as weeds. She believes everything has a place and everything needs to eat. Evidence of some flea beetles on her still-growing-strong eggplants don’t bother her. She uses pests as prompts to examine what she’s doing and responds, over time, by focusing on nutrients.

She plans to devote more attention this year to brassicas, as the Brix numbers are not as high as she wants and she wants to achieve longer shelf life.

Focus on Nutrient Density

Whether it’s the longevity and lack of pests and disease on her tomatoes, the bounty of her basil — she had been bringing about 40 bunches a week from May to August to Foods of All Nations in Charlottesville — or the size of the Chesnok Red garlic, the bounty of Hill’s farm and the quality of her produce point to an interesting question for growers and others: What is the genetic potential of produce?

We don’t know. The situation is much like that of trying to figure out what a forest is by looking at a second- or third-growth forest; there may be some tall trees, but given environmental changes and disturbance, are those trees living up to their full genetic potential?

The search for quality marks a third phase in agriculture, according to nutritionist Barbara O. Schneeman in “Linking Agricultural Production and Human Nutrition,” in the Journal of the Science of Food and Agriculture. The first phase focuses on yield and ensuring an adequate supply of food. The second hones in on efficiency as a way to increase diversity among sources of nutrients. The third includes targeted ways to improve the nutrient density of particular foods as a way to promote health. We are living in the transition to the third.

“As farmers, we’re not paid based on nutritional value,” said Kittredge. “People have been focused on volume and aesthetic, not animal instinct based on what our nose and tongue tell us.”

Dr. Fred Provenza, professor emeritus in the Department of Wildland Resources, Utah State University, agrees. At an Acres U.S.A. Conference workshop, he used the example of strawberry-flavored Gushers to show how our palates have been hijacked: “You’re getting this big blast of energy because of the corn syrup [in the Gushers], but none of the phytochemicals [found in strawberries].”

“Conventionally, we have made a division between palatability — what a body likes to eat — and nutritional needs — what a body needs to thrive — based on our experience of liking or not for the flavors of foods,” he says. “In the process, we assumed we like foods because they taste good and dislike foods because they taste bad. We didn’t consider that foods taste good when they meet the needs of cells and organ systems, including the microbiome, and they taste bad when they don’t. Phytochemically rich combinations of foods satiate because they meet needs, and they can actually cause us to eat less, not more, food.”

Phytochemical richness — which includes a diversity of primary plant compounds (energy, protein, minerals and vitamins) and secondary plant compounds (phenolics, terpenes, alkaloids, etc.) — creates flavor and links palates, human or ruminant, with nutritional needs, says Provenza.

Fortunately for growers and eaters alike, this richness is influenced by what goes on in the soil. Kittredge likens the process to establishing (or re-establishing) “gut flora” for plants. No matter whether the plant is alfalfa or an apple tree, the idea is to feed the bottom of the food chain, by ensuring proper conditions for biological activity — for life to flourish — and that, in turn, will feed the top — that is, what’s above ground. Growers have the ability to assist in the process. Eaters also exert influence through their palates through which growers, and whose practices, they choose to support. It’s the essence of a feedback loop.

Where to Begin Growing Nutrient-Dense Crops?

For anyone interested in adopting a quality-based, nutrient-dense approach, there are many places one could start, but why not begin with seed? Kittredge notes that the majority of growers will not get the best seed available — won’t get the best genetic potential, in other words, as others, including seedsmen themselves, typically have dibs on them. That’s why it’s important to focus on seed size when ordering. Large seed size — measured as fewer seeds per pound — indicates greater vigor and germination speed. As one example, Kittredge found the range for Bolero carrots to be 800,000 to 100,000 seeds per pound.

Starting with the best seed makes things easier, but then growers can influence subsequent generations through how they support the soil and the plants. In his workshop, Kittredge shares a story about arugula. He called around to three different seed companies to find out, not germination rates, but rather how many seeds per pound they were offering. He bought 4 pounds of arugula with the greatest seed size. He planted 3 pounds and used his usual practices of biomanagement, picked and assessed the plants and let them go to seed.

He harvested the seed and then planted that along with the remaining pound of arugula seed later in the same season. With the saved seed, he saw “a dramatic increase in germination speed, vigor and functional yield” in terms of leaf size and thickness, plus pest resistance, a decrease in purpling and an increase in cold tolerance.

After acquiring your seed, inoculate it. Kittredge says that’s where growers get their best bang for the money spent — and if you make your own inoculant, you may not need to spend anything. He recommends ensuring that the seed inoculant is broad spectrum and includes a dozen fungi and a couple dozen bacteria families.

To begin managing the soil for quality, understand what’s going on there. A soil electrical conductivity meter can help you begin to understand the influence of your soil on your plants as well as your cultural practices, such as hydration and temperature maintenance. Is the soil moist enough? Are you keeping it covered well enough, either with cover crops or mulches?

In North America, it’s fairly easy to find the nutrients needed to correct deficiencies, but Kittredge says remineralization is needed worldwide, and the least expensive ways to start remineralizing are through rock dusts — anywhere there’s asphalt, there is usually a local quarry that provides the crushed rock — and sea minerals.

Basalt-based rock dusts don’t cost much per ton; more money will be spent on delivery. The BFA, through its local chapters, has begun to create mineral depots to help in this process, though they are not available everywhere.

Amend Based on Soil Test Results

Get a high-quality, Albrecht-type soil test that checks for macronutrients as well as trace minerals. Kittredge suggests testing at the autumnal equinox and applying any nutrients to counter deficiencies in the fall as, in most places, things are going dormant. Focus on the most nutrient-deficient areas — whether a few acres or a few hundred square feet.

Based on your test results, determine what you need using these calculations:

Ppm (parts per million) multiplied by 2 gives you the lb/acre (pounds per acre) needed. So, for example, if you are looking at sulfur, the target is 75 ppm or 150 lb/acre. Your soil report indicates you’ve got 16 ppm. Multiply the 16 by 2, which shows you have 32 lb/acre. With the target of 150 lb/acre, subtract 32 from 150 (150 – 32 = 118), which gives 118 lb/acre of sulfur needed.

If you take something such as gypsum, you’ll see its sulfur content is 19 percent (19 percent of a 100-lb bag). If you need 118 lb/acre, you divide 118 by .19 (convert the content percentage to a decimal), which gives 621 lb/acre. The gypsum of course also has calcium. So, you can run the same process for calcium and start at 500 lb/acre of gypsum. (For gypsum, says Kittredge, all of the elders he spoken with say to apply no more than 500 lb/acre at any one time.)

Make sure the nutrients are tied to a carbon source, so that they don’t burn plants or soil life. For example, they can be mixed with humates and broadcast-spread — which is what Kittredge does, letting his “livestock” partners, the earthworms and other soil fauna, work them in — or layered within a compost pile, or combined with molasses or sugar and sprayed on.

Kittredge says to think of the soil like you would your gastrointestinal tract. How do you feel after eating a big meal? It’s the same with soil; too much cannot be easily digested, so it’s best to apply some nutrients and test again later to see how things are moving and continue to apply and retest until conditions are optimal. Doing too much can create excesses, which are much more difficult to correct than deficiencies.

As you apply and retest, you’ll also be checking yields and quality. This is where the conductivity meter and refractometer come in. Kittredge suggests testing once a week, about 7 a.m., and spending an hour at that time to check your plants. You are not using just these tools, but making visual and organoleptic inspections to correlate the numbers with plant growth and plant habits. In time, this facilitates a far deeper perception of what’s going on belowground and how it’s affecting what’s above and what adjustments you may need to make.

Closing the Loops with Feedback

In his research with ruminants, Provenza found that health ensues when wild or domestic herbivores forage on landscapes rich in phytonutrients, but not so much when they forage on monoculture pastures. He also found their health really takes a hit when they are in feedlots. The same, he says, is true for humans “who forage in modern food outlets.”

But the links between the impact of soil on plant health (and plant health on soil activity) and the flavors of those plants and how they influence human health are only beginning to be assessed. That’s a challenging process due to the multitude of variables at work. Humans don’t make for good experimental controls because we seldom eat the same thing every day.

Still, eaters and growers can help increase knowledge through two tools BFA supports. One is the Bionutrient Meter, a tool that uses spectroscopy to determine the nutrients and compounds present in a food. Now in the prototype stage, it’s anticipated the tool could become available on next-generation phones. Users would “scan” produce by flashing a light at it to assess the levels and ratios of nutrients and compounds.

Kittredge says findings from the tool will help growers understand how healthy their crops are while in the field and what can be done to increase their vitality before harvest. Eaters could use the tool to choose which items to purchase at the farmers’ market or supermarket.

The core idea is that transparency will help align the supply chain with food quality and that will have a cascade of effects, ranging from sequestering carbon in the soil to reversing and preventing degenerative disease.

Peer-to-Peer Platform

Growers also have an opportunity to help by recording and sharing their own data and observations through FarmOS, an open-source, peer-to-peer platform under development.

“It’s in service for this ideal of global knowledge and local production,” said Dr. Dorn Cox, founding member of the FarmOS community, research director at Wolfe’s Neck Farm in Freeport, Maine, and farmer on his family’s 250-acre diversified Tuckaway Farm in Lee, New Hampshire. A variety of farming operations have been included to help build out the platform — mixed animal, dairies, market gardens and small grains and oil seed.

Cox says it’s a big commitment for farmers, much like implementing Quickbooks. As the project moves forward, things should become easier, such as through voice-activated observations and recordkeeping to minimize the need for farmers to stop to make notes.

Even though FarmOS is in the early stages, Cox has been impressed by how much can be learned from just two soil indicators — moisture and temperature.

“It comes back to those core principles of building soil health and keeping photosynthesis going as much as possible,” said Cox, who has a Ph.D. in natural resources and Earth systems science. “Water is one of the most limiting nutrients in any environment. It’s almost always in surplus or deficit. Soil temperature is really important for biology — just that little mulch is critical to keep soil in a certain temperature range to function biologically.”

Cox had seen all of that before, but had not recognized how sensitive soil bacterial and fungal populations are to temperature.

The effectiveness of practices such as maintaining diverse rotations and not tilling can be somewhat measured through moisture and temperature, he says.

With FarmOS’s common open architecture, farms that are similar will be able to work together and even where they are different, they’ll be able to tailor biological management practices based on what they can glean from other farmers.

A tool like FarmOS, which can confirm what kinds of practices help to build soil, “gives every farmer the chance to be the best farmer they can be,” said Cox. “You can only experiment so much each year, but if you collaborate, you’ve just extended your lifetime. That’s exciting.”

Editor’s Note: This article appeared in the May 2018 issue of Acres U.S.A.

Learn more about the Bionutrient Food Association and Dan Kittredge and Broadfork Farm.

Building Humus For All Crops

This excerpt is brought to you by Book of the Week – offering you a glimpse between the pages and an exclusive discount of a new book each week. Get the Book of the Week email newsletter delivered directly to your in box! This week’s Book of the Week is Humusphere, by Herwig Pommresche.

The term “soil humus content” refers to the totality of all the organic substances present in the soil. It is often expressed in terms of carbon content percentage, as carbon is the basic building block of organic material. But this definition is insufficient as it only reveals the sum of all the carbon atoms contained in the soil. How much of that is valuable compost, living soil biota, liquid manure, or other organic substances is not clarified. A relevant quote comes from M. M. Kononova’s treatise, “The Soil’s Humic Substances – Results and Problems in Humus Research” (1958):

“The history of humus research is rich in incorrect approaches to clarifying important questions, which has led to contradictions and confused ideas about the nature of humic substances, their origins, and the role they play in forming the soil and determining its fertility.”

But if we primarily understand “humus” as referring to the abundance of organic substances present in the soil, we overlook its mineral content. The proportion of minerals has increased in cultivated soils during our era in comparison with past eras in which consistently humid heat promoted the formation of organic soil material over huge swaths of forest for thousands of years.

The ratio between the organic and mineral portions of the material has shifted, to the detriment of the soil.

 Incidentally, this is a particularly strong example of the importance of using the right terms with the right meanings: the word “mineral” is here used correctly to refer to everything from rocks, gravel, and sand to the very finest mechanically ground particles – it has absolutely nothing to do with NPK fertilizers or other salt ions.

One small calculation is sufficient to get an idea of the significance of plant roots in the soil: “The formation of root hairs greatly increases the root’s surface area. Rye (Secale cereale) has about 13,000,000 roots with a surface area of 235 square meters, and 14,000,000,000 root hairs with a surface area of 400 square meters in 1/22 of a cubic meter of soil (…) The surface area of the underground portions is thus 130 times as large as that of the above-ground portions” (Jurzitza 1987, 28).

One single rye plant has the equivalent surface area of an entire garden in direct contact with the soil in which it grows. What this soil is made up of has to be crucially important.

Annie Francé-Harrar (1957) wrote the following about how healthy soil should look for plant roots to be able to optimally carry out their work:

“Ideal soil should have the following composition: 65 percent organic material, 20 percent edaphic organisms, 15 percent mineral substances. (…) But this kind of abundance of organic material exists hardly anywhere on the planet any more, the highest concentrations being in untrodden corners of tropical jungles, but never in our growing soil. But it is possible to restore the organic-inorganic balance in growing soil within a practical timespan through systematically employed humus management.”

These recommended ratios also provide a target to work toward in systematic humus management. But she was already well aware of how difficult it is to put this into practice:

“But this (…) means a radical agricultural revolution, much larger than the one triggered by Liebig in his time” (20).

How does humus form?

Topsoil formation is very much a classic case study in the movement of living material from the waste material of living things into plants, of the descent of living material into Mother Earth.

It’s also a study in the soil, of its many functions, of its conversions and storage until its reappearance in the world of above-ground organisms. The bulk of the soil material first becomes clearly visible as nutrient-forming chlorophyll, but that chlorophyll would never exist without the work of the countless organisms in the soil.

The same species of bacterial symbionts appear in almost all animal and plant organisms, the lactic acid bacteria. In fact, soil probes from all over the world, even if the soil in question is only slightly fertile, always contain large quantities of lactic acid bacteria. The soil contains more of them, and of better varieties, the more fertile it is. This is further evidence that the cycle of living material takes place in the topsoil through the mediation of bacteria.

The remnants of biological processes on the surface, processed by countless species of small creatures, are first processes into precursors by budding fungi species, predominantly yeasts and molds, and then passed along to the bacterial symbionts in the soil. According to the most recent research, these symbionts—lactic acid bacteria in this case—can be directly consumed and digested as food via endocytosis by plant root hairs (Rateaver and Rateaver 1993), and they leave all kinds of organic material behind after they die, especially in the fall.

These particles, as well as the bacteria themselves (i.e., the living material in the soil bacteria), are a prerequisite for the formation of high-quality soil: topsoil that is aerated, loose, water-retaining, capable of biological tillage (Sekera 2012), safe from erosion, and fertile, the result of the functions of the edaphon, as outlined by Henning (2011).

The adhesiveness of the microorganism residues  cements the inorganic mineral substances of rock erosion into soil crumbs. In contrast to the views of agrochemists, it is this alone that deserves the name “humus” in the biological sense: a conglomeration of organic and inorganic material. And this means that it is completely impossible to describe humus as a dead, chemical substance!

Humus formation is a sort of “organic predigestion” for plants; and at the same time, humic soil serves as a pantry of living nutrients during the growing season, when plants can grow only if supplied with sufficient warmth, water, and sunlight.

Otherwise, however, the parallels between animal and plant digestion are unmistakable. In both cases, microorganisms serve as an intermediate station, as “nutrient facilitators,” and in both cases organic or inorganic material can be extracted as needed from the nutrient substrate and used to build cells and tissues.

Edaphon: The “Residents” of the Humusphere

Just as the water has plankton, there is also “the plankton of the soil,” as Raoul H. Francé so singularly described and illustrated the term “edaphon” for us in 1911. The whole fertility of the humusphere depends on this edaphon, and it contains the entire existential basis of our life on this planet. The biosphere carries out its own cycle via its own living beings.

edaphon soil microbe found in humus
Euglena spec. is a single-celled organism containing chlorophyll and a member of the
“plankton of the soil.”

Under the heading “Ein Buch mit vielen Siegeln” (“A Book with Many Seals”) in “Mensch und Umwelt,” J. Filser (1997) writes:

“Microorganisms in the soil can contribute to the nutrition of a plant or strengthen its resistance to pathogenic organisms or the effects of environmental damage. [. . .] They represent a biological potential that promises a wide variety of useful applications in protecting our resources in agriculture and forestry. [. . .] Thus far, only a limited portion of the soil microflora has been cultivated and examined in more detail. We are not even aware of an estimated 90 to 99 percent of soil organisms.”

Edaphon: Plankton of the soil

Just as plankton provides the basic conditions for all further life in the hydrosphere (i.e., in the water) the edaphon provides the basic conditions for all further life in and on the soil.

But it’s possible that even larger quantities of proteins are hidden within it than in plankton! A comparison accentuates this point: the average human biomass in the United States is 18 kilograms per hectare. On the other hand, the average biomass over the same area of insects, earthworms, single-celled organisms, algae, bacteria, and fungi is about 6,500 kilograms. That’s more than 350 times as much!

To break it down more specifically, that’s 150 kilograms of single-celled organisms, 1,000 kilograms of earthworms, 1,000 kilograms of insects, 1,700 kilograms of bacteria, and 2,500 kilograms of fungi (Gaia 1985, 150).

And what’s the breakdown in our gardens? In a 1,000-square-meter garden, 1,000 kilograms of edaphon lives and works in complete silence, without disturbing the neighbors, all year long.

The biomass of the earthworms alone—who represent a part of the edaphon—can be determined by any interested layman by collecting and weighing them. In sandy soil beneath conventional barley, I’ve found 9 grams per square meter of surface area (to the depth of a spade), 49 grams beneath conventional pasture, and 840 grams in my own biologically cultivated garden soil. Per hectare, or 10,000 square meters, that comes out to 90, 490, and up to 8,400 kilograms of living biomass respectively. And that’s just the earthworms?

The ideal for fertile growing soil is (Francé 1911, 1995): 1 kilogram of living biomass or edaphon per square meter of garden or field soil. One kilogram of living cytoplasm per square meter corresponds to 1 metric ton of biomass per 1,000 square meters, or 10 metric tons per hectare. Ten hectares of cultivated field soil thus come with 100 metric tons of living biomass in the form of the edaphon beneath the ground—and that’s without even considering what can be achieved above the ground. That comes out to the weight of one thousand hogs or two hundred cows!

For readers who are farmers: these numbers reveal how much “livestock” you have hidden on your farm, without ever seeing or noticing it. If you converted this quantity into actual livestock, how much would you have to supply them with on your farm in terms of feed, stalling, ventilation, weather protection, and eventual excrement disposal? How about veterinary costs, consultation, and researching?

This is only hard for us to conceptualize because we have neglected it in the models we use to teach and think about agriculture. If you think about these numbers in the context of the new, still unfamiliar “plants can digest protein” model, you quickly recognize the new possibilities that they reveal for our agricultural practices.

Source: Humusphere

About the Author

Herwig Pommeresche was born in Hamburg in 1938 and has lived in Norway since 1974. He received a degree in architecture from the University of Hanover. He has spent many years active as an architect and urban planner in Norway. After finishing his studies in architecture, he became a trained permaculture designer and teacher under the instruction of Professor Declan Kennedy.  Alongside other permaculture experts, he served as an organizer of the third International Permaculture Convergence in Scandinavia in 1993. He later served as a visiting lecturer at the University of Oslo. Today, Herwig Pommeresche is seen as a pillar of the Norwegian permaculture movement. He also serves as an author and a speaker.

Herwig Pommeresche is a holder of the prestigious Francé Medal, awarded in 2010 by the Gesellschaft für Boden, Technik, Qualität (BTQ) e.V. (founded in 1993) in recognition of his contributions to organic methods and ways of thinking and to the preservation and improvement of the humusphere.

Watering Best Practices for Crops

By Charles Walters and Esper K. Chandler

All any farmer really wants is the best uptake of plant nutrients for his or her crops. In order to make sure crops efficiently uptake all they need, crop expert Esper K. Chandler says, “We have to reestablish the humus function of the soil, the basis for natural/organic sustainable farming.” And this means putting water best practices into use.

The drip-irrigation system is a valued key to best watering practices. Not only does it make it possible to feed the plant vital nutrients – especially phosphates – on a cafeteria basis, it enables uptake of existing soil phosphates, thereby doubling the potential.

Drip irrigation for crop water management

Then multiple products of humus, lignosulfates, enzymes, soil inoculants, hormones such as in seaweeds, cytokinins, auxins, and gibberellins bring on another synergistic effect, all of them answering the plant’s call for help.


Non-toxic Management Practices for Weeds

Charles Walters describes important farm management practices concerning soil health and the identification and non-toxic treatment of weeds.

By Charles Walters

For now, it seems appropriate to walk through farm management practices worthy of consideration. How they fit soils in any area and how they dovetail with crop systems projections becomes all important for the grower who wants to minimize the hazards of weeds so that he does not have to depend on the obscene presence of herbicides to control them.

Fall Tillage

Fall tillage has to be considered number one. It is the first thing a farmer should want to do, yet every fall when the crop is harvested, that bad weather always seems to arrive. Often the fall work does not get done. The farmer is too busy harvesting and he can’t get in there and do the tillage.

Moreover, most crops are harvested late because schoolbook technology has given us degenerated soils. We do not convert and use fertilizers, nitrogen and other fertility factors locked up in the soil to properly grow field-ripened crops.

Proper fertility management would see to it that harvest can take place a month earlier and thus permit time for that fall work. That is when compaction could be best removed, when trash could be mulched in. That is also the time when pH modifiers could be applied. That is when lime and other nutrients could be used to influence the quality and character of the soil’s pH, all in time to meld into the soil during fall and over winter.

It is this procedure that would make the soil come alive in spring and get the growing season underway so that crops can germinate a week or ten days earlier.

Fall tillage is an important key to weed management. It is certainly one way to diminish the chances for foxtail and grass type weeds. If fall tillage is used to put soil systems into ridges, those ridges will drain faster in spring. They will warm up a week to ten days earlier. They will have germinating capacity restored earlier and permit planting earlier so that the economic crop can get a head start on weeds.

Once the soil is conditioned, it won’t be necessary to turn the soil so much in spring. Obviously, every time the soil is turned, more weed seeds already in the soil are exposed to sunlight and warmth and other influences that wake them out of dormancy. Soil bedded in the fall, with pH modified so that the structure does not permit crusting when spring rains arrive, will permit rain to soak in faster, bringing air behind it. Such a soil will warm faster and therefore determine the hormone process that will take place. Good water and air entry into the soil will not likely set the stage for foxtail (image below), nut sedge, watergrass and other debilitating influences on the crop.

Foxtail can be avoided with practical weed management
Anhydrous ammonia is almost an insurance policy for its proliferation. Foxtail grows in organic matter soil where there is a surplus of humic acid. Although pH adjustment has been front burner stuff so far, the topic has to surface in any discussion of the foxtail weed problem.

When the cash crop is germinated under these conditions, that is when your little pigweeds and lambsquarters, your broadleaf weeds — which require a good quality available phosphate — hand off their message. They say the phosphate conversion is good and the fertility release system is more than adequate to grow a high-yielding crop.

Such broadleafs are easy to manage. When they germinate and achieve growth of an inch or less, and you tickle the soil before you insert the seed, they are easily killed off. As a consequence, the hormone process gains the upper hand for four to six weeks, a time frame that permits the crops to grow big enough to be cultivated.

Organic Materials in the Soil

Needless to say, the bio-grower has to depend on proper decay of organic materials in the soil. Root residue and crop stover are always present, and these have a direct bearing on how prolific weeds might grow. This means farmers, one and all, must learn how to manage decay of organic matter better.

As we incorporate it into the soil, preside over proper decay conditions by pH management and regulate the water either present or absent, we achieve plenty of air and good humid conditions that will allow organic material to decay properly and in the right direction to provide the steady supply of carbon dioxide necessary for a higher yield.

While adjustments are being made in the soil — soils are sometimes out of equilibrium for years — it is unrealistic to expect the situation will be corrected in a single season or a single month. We can speed the process with the application of properly composted manures. The point here is that there is a difference between quality of various composts, just as there is a difference between predigested manures and manures sheet composted in the soil itself.

Readers of Acres U.S.A. in general, and those who have enjoyed the short book, Pottenger’s Cats, will recall how that great scientist planted dwarf beans in beach sand at Monrovia, California, as part of an experiment. Cats had been raised on that beach sand. Some had been fed evaporated milk, others raw meat, still others meat that had been cooked to achieve near total enzyme-destroying potential and some had been fed on raw milk. Cats fed evaporated milk, cooked meat — dung going into the beach sand — produced a dilapidated, depressed crop of beans. Cats fed whole milk — their dung also going into the beach sand, produced a prolific and extended crop, the dwarf bean variety growing to the top of a six-foot-high cage. The quality of manures used in composting have a direct bearing on the performance of that compost.

Experience has taught all those who wish to see that the kind of compost Fletcher Sims of Canyon, Texas, introduces into the soil has many desirable fungal systems of bacteria and molds. These have the capacity to attack rhizome roots of quackgrass, Johnsongrass, and those type of roots so far under the top of the soil they cannot be reached with physical tools. Compost tells us that we have to set in motion an environment with antagonistic fungi that will attack the rhizomes when they are in a dormant phase as the season begins to close.

In late August and early September, the length of the day shortens. Everything starts to go into fall dormancy. If at that time we can apply a wholesome, properly composted material to the soil and have it working for thirty days before the soil freezes and becomes inactive, a lot of weed cleanup work takes place at that time. Compost will simply digest most of the dormant weed seeds, and in two or three years of this approach seeds are literally vacuumed up, like soil particles on the family room carpet.

The key is timing. When weeds go into dormancy, they are subject to decay. They can be turned into fresh humus, rather than a charge of gunpowder ready to explode. Quackgrass in particular responds to the compost treatment. With calcium-adjusted pH, compost will attack quackgrass roots and rot them out in one season. The same principle operates with deep-rooted rhizomes, Johnsongrass and thistles.

Quackgrass signals soil decay systems are poor
Quackgrass, sometimes called couchgrass. Agropyron repens is shown here (A); its spikelets (B); the ligule (C); and florets (D). Decay systems are at fault when this weed appears.

The simplest way to start a biological weed control program, then, is to adjust the pH. This affects the intake of water and makes it possible to manage water.

In the cornbelt, where rain often comes at the wrong time and where droughts frustrate the best of intentions, this management of water and its capillary return is front burner stuff. pH management directly relates to so many desirable things, there is justification for referring the reader to the several volumes of The Albrecht Papers for background insight.

Soil Management

Each weed has a direct bearing on the track record of the farm. Each reflects back to what the farmer has done correctly or incorrectly over the years. Too often — in this age of super mechanization — we have large fields with soft spots and hard textured soils. The farmer moves across one then over the next area because he feels impelled to farm big fields with big machinery. All the low soil is too wet, and so a pass through sets the stage for wild oats or foxtail in corn, or fall panicum.

Some soils get the wrong treatment simply because they, not the weeds, are in the wrong place. It may be that the eco-farmer will have to redesign the shape of his fields, or plant in strips so that similar types of soils can be planted at the same time, with due regard being given to the need for soils to dry out and warm up and drain properly. It might be better to wait a couple of weeks. A little delay is better than wet soil work which leaves no chance at all for a crop.

As far as weeds as related to insects, the great Professor Phil Callahan has given us a roadmap that cannot be ignored. He called it Tuning In To Nature, and in it he related how the energy in the infrared that is given off by a plant is the signal for insect invasion.

It stands to reason that a plant that is subclinically ill will give off a different wavelength than the one with balanced hormone and enzyme systems. That these signals match up with the signals of lower phylum plants is more than speculation.

While writing An Acres U.S.A. Primer, I often made field observations that supported Callahan. It became obvious that when farmers did certain things in the soil, the crop could endure the presence of insects because they seemed incapable of doing much damage. I didn’t know how the mechanism worked, at least not before the release of Tuning In To Nature.

Weeds are going to tell about the nutritional supply, and they therefore rate as a worthy laboratory for making judgments about the soil’s nutritional system. They can often reveal the nutrients that must be added to the foliage of the growing crop to react with the negative effects of stress. After all, all growing seasons have variable degrees of timing and stress. It is not only necessary to arrive with nutritional support in time, it is mandatory.

The many mansions in the house of weeds all have family histories. They tell more about gene splicing and DNA manipulation than all the journals of genetic engineering put together. And if we pay attention during class, weeds are our greatest teachers. To learn our lessons, we have only to get into the business of watching weeds grow.

Source: Weeds—Control Without Poison 

Forage Mixtures: Soil Types

By Newman Turner

Editor’s Note: This article is a part of our series on Forage Mixtures.

All the herbal ley mixtures are suitable for use as four-year leys where it is usual to break the ley after four years. Three years is too short a period in which to derive maximum benefit either in yield of grass or soil fertility; and I consider four or five years the optimum life. Each mixture is, however, basically also a permanent pasture mixture, so may be left down longer if necessary.

The quantities of seeds making up the mixtures are the ideal for quick establishment and soil coverage; but where extra economy is necessary in seasons of high-priced seeds, the eventual pasture, though slower to ‘fill up,’ will be ultimately just as good with up to a third less seed, thus reducing the cost by one-third. But soil conditions, seedbed and fertility must be perfect for this reduction of seed quantity.

Herbal Ley Mixture for Very Thin, Dry Soils

(and to resist extreme drought conditions)

Herbal Ley Mixture for thin, dry soil

The main essential of a mixture for thin soils, soils overlying and close to the rock, and in excessively dry countries, is that it should contain a predominance of the deepest-rooting varieties available, consistent with their production above the ground. This makes the most of such little moisture as is present in the deeper subsoil; and where the subsoil is largely rock some penetration of the rock can be achieved by the more powerful of the deeper rooters.

Every one of the ingredients of this mixture is an exceptionally deep rooter, except the clovers S.100, Trefoil, Alsike and Late-flowering Red—and even Alsike and Trefoil and reasonably drought-resistant. All prosper on the thinnest soils; but the mixture is not ideal for good deep soils.

Grass mix
Lucerne (alfalfa) and Timothy grass

Lucerne or Alfalfa Mixtures

Lucerne Pastures for Silage or Grazing

Lucerne pastures for silage or growing

In a wet season, which the lucerne does not enjoy, the Red Clover and S.100, together with the grass, prosper and produce a large bulk. In a very dry season, when the shallower clovers suffer from drought, Lucerne will make up a full crop almost single-handed.

The Chicory will thrive under all conditions.

For silage only, omit S.100 and reduce Red Clover to one pound in each case.

Source: Fertility Pastures

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What Weeds Tell Us About Soil

Weeds are not inherently bad by nature. The informed farmer will know what the presence of various types of weeds means – from compacted to overly wet soil, and more. The late eco-farming expert and Acres U.S.A. founder Charles Walters explains different types of weeds, and the soil conditions and state of soil health that their presence signals.

By Charles Walters

Andre Voisin, the great French farmer and scientist who wrote Soil, Grass and Cancer and Grass Productivity, once declared that most of what he knew came not from the university, but from observing his cows at grass. And so it is with much of what we know about weeds.

Walking the fields with the late C.J. Fenzau in areas as separate as Indiana, Iowa and Idaho, I was able to take note of what weeds were trying to tell us during the early days of the Acres U.S.A. publication. Admittedly, this knowledge has been fleshed out since then. And recent findings build on, rather than tear down, those field observations.

Weeds are an index of what is wrong — and sometimes what is right — with the soil, or at least with the fertility program. In every field on every farm, there are different soil types, and each has a potential for producing certain weeds, depending on how a farmer works the soil. Fall tillage, spring tillage, tillage early or late, if it takes place when the soil is dry or wet, all these things determine the kinds of weeds that will grow that season.

Weeds and Water

As far back as the Dust Bowl days, it became transparently obvious to my Dad — after viewing rainbelt territory near Conway, Missouri — that dryland weeds generally don’t grow in territory that has rain pelting the soil with a steady squall. Thus the presence of salt grass, iron weed, tumbleweed and all the wild sages in soils where flocculation is gone, and wind wafts dust skyward.

There are soil conditions that almost always have restricted amounts of water, and consequently they do not require and cannot grow weeds that thrive when there is plenty of water.

In high rainfall areas of the United States, where irrigation is paper thin and where farmers depend on rainfall for their crop moisture, broadleaf weeds — lambsquarters, pigweed (image below), Jimson weed, buttonweed, and so on — often proliferate.

Weeds and soil – pigweed likes moisture
Green Amaranth, a.k.a., palmer amaranth, careless weed, spleen amaranth, red amaranth, rough pigweed, smooth pigweed, pigweed.

These special conditions appeared classic when C.J. Fenzau and I walked several farms near What Cheer, Iowa, one summer. Where the soil structure was poor and farmers worked the soil under wet conditions, they usually built compaction or set up sedimentary levels in the soil from filtration of silt. This set the stage for a lot of grassy weeds. And in only moments, it seemed, the corn farmer is forced to endure the vicious effects of foxtail and fall panicum.

The soil’s potential might remain. For the season, this pattern of weeds indicates a degenerated soil structure. That’s the signal foxtail and fall panicum send out loud and clear — that there is an imbalanced pH condition in the soil, that tight soil is holding water in excess and refuses to permit it to dry out.

As a consequence, the farmer is always working his soil system on the wet side and creating clods. When he gets done planting fields with clods, they accumulate excess carbon dioxide. Foxtail and fall panicum like carbon dioxide. This triggers certain hormone processes that wake up the foxtail seed and say, It is your turn to live and multiply.

To control the foxtail, it now becomes necessary to change the structure of the soil, and this means tillage, fertility management — not least, pH management, efficient use of water, development of capillary capacity and aeration of the soil. This much accomplished, there is no need for atrazine or other chemicals of organic synthesis.

I recall that in one corn field, planting had been delayed — sure enough, a pattern of rye grass made its stand. Here the crop was planted too long after cultivation. By the time seeds went into the soil, weeds were on the way.

I recall one alfalfa field that had been the victim of poor soil management for seven or eight years. The soil was waterlogged and distressed. And weeds of several types increased and multiplied. It became standard procedure to recommend pH adjustment according to the gospel of Albrecht, and well digested compost. Compost contains its own nitrogen in perfectly available form. It often acts as a precursor of bacteria-fixing nitrogen in the field. Even then it was axiomatic that you never get blue-green algae with N, P, and K.

This business of management, or lack thereof, figured everywhere the Acres U.S.A. pencil and camera went. At one western dairy, it was practice to cut hay and treat it on the spot with an enzyme hormone complex, bio-cultured by Albion Laboratories out of Clearfield, Utah. In a matter of hours, the crop was put up as part of silage or hay bales. Before nightfall the same field got its shot of irrigation water. Weeds rarely got a toehold in such a well managed field, even though herbicides weren’t used.

The Hierarchy of Weeds

Weeds seem to have a pecking order. Once the conditions that permit foxtail and fall panicum are erased, there will be other weeds, but none of them will be as difficult to control or as hazardous to crop production. They have names, both Latin and common. Lambsquarters is one. Pigweed is another. But now the message is different. Both lambsquarter and pigweed say soil conditions are good and fertility is excellent, and there is no reason to come unglued when they appear, for they are as Joe Cocannouer says in Weeds, Guardians of the Soil, a message that the crop will thrive and insects will stay away.

Cocklebur (image below) also indicates that the soil’s phosphate level is good. Lambsquarters, pigweed and cocklebur suggest a trio of superlatives, namely wholesome, highly productive, good quality soils. They are not hard to manage with clean tillage, and do not call for inputs of chemistry from the devil’s pantry.

Common cocklebur tells the farmer that his soil has a high level of available phosphate and a reasonable pH level. These high levels of phosphate tend to complex zinc, which activates the cocklebur’s hormone system. Xanthium pennsylvanicum is shown here with its root (A); seedling (B); bur (C); seed (D). One look at cocklebur should tell a farmer not to fertilize with phosphate.

In watching crops grow, other clues have surfaced over the years. There are relatives of grasses that reflect wet soils and wet conditions. Barnyard grass and nut sedge warrant mention. On the other side of the equation, the same soil that produces each of these nemesis can produce ragweed (image below), a dry weather phenomenon. This is particularly true when the crop is one of the small grains. Often the soil tends to dry out as the crop matures. With soil moisture low, bacterial systems do not function too well because, of course, they require water. They do not function to release or convert potassium in a proper form. When the potassium supply from the soil is restricted for whatever reason, or held in a complex form, ragweed reveals itself inside the grain crop. With harvest, contamination in the grain bin becomes apparent.

Carolus Linnaeus called Western ragweed ambrosia psilostachya, thereby exhibiting a wry sense of humor. The illustration exhibits the plant itself (A); its raceme of male heads and female involucres (B); the achene or one-seeded fruit (C); and seeds (D).

Ragweed (image directly above) tells the farmer that he has poor quality and a wrong form of potassium during the dry part of the crop season. In the cornbelt, when there is too much rain after fall plowing, and in early spring when cold, cloudy weather holds on for a three-week period, then fall-tilled fields still open will generate a whole new crop of bitterweed or smartweed. These arrive under wet soil conditions and grow early in the season. They are related to poorly structured and poorly drained soils. More important, these weeds shout out in understandable terms that something is wrong with the direction of decay of organic matter. Soil that is not in the proper equilibrium will put the decay process into the business of manufacturing alcohols and formaldehyde — in short, embalming fluids.

A good example is often the progenitor for morning glories and other rhizome crops that defy destruction. Picture cattle being fed out on the edge of a field. A lot of waste hay and straw piles up, cemented into place by urine and manure. Two or three years later this mixture is turned under, usually in an effort to return the area back to crop production. The problem is that Jimson weeds and buttonweeds, not crops, will grow. There is a reason for this. They are growing in soils with an excess of organic material that is not decaying properly. A hormone-enzyme process of a different bent takes over. It wakes up weed seeds and allows them to flourish.

The solution is not an overdose of herbicides, but manipulation of pH, distribution of the pileup of organic matter, which in any case must be mulched in more completely. When decay starts to go in the proper direction, Jimson weeds and buttonweeds simply stay dormant and no longer grow in that area. The same principle applies to morning glories and field bindweeds. The last two weeds grow in sick soils, in eroded soils, and in each case they increase and multiply because they are started by an improper decay of organic material.

Sometimes the decay process produces formaldehyde, and at certain stages there is methane, ethane and butane production. These byproducts of decay stimulate the birth of the hormone systems that penetrate ubiquitous weed seeds and tell them to come alive and establish the growth kingdom for that season.

Generally, these processes do not occur throughout the entire field. Almost always, it is a spot here, an eroded hill there, always areas in which something has gone wrong in the past. These are dangerous weeds, and they are very destructive. They climb up plants and drag them down. They short-circuit yields and confer harvest problems on the best of machinery, and often account for farm accidents. Many farmers are maimed for life because they have tried to unplug harvesting equipment, the missing hand or arm a legacy of improper soil management.

Weed Patterns and Crop Performance

There are many factors that have a bearing on weed patterns and crop performance. They’re all interrelated. The ideal is to have pH control, good loamy soil texture, enough decaying organic matter to set the things in motion for better crop and changing weed patterns. These things diminish the frictions of stress and myriads of things that happen.

Every year conditions are different and there has to be different timing. Variables invite changes. There is no way you can machine the process. You can have watergrass come into a waterlogged soil. The next year you waterlog it early and let it dry, and in the early part of the season you get smartweed, a variable of stress reaction.

Different conditions invite a different echelon of life to come in. There is a variable in man — his operating style. I recall a farmer who had everything going perfect. But this year instead of taking a spiketooth rake and dragging it over the corn as it was emerging, the worker assigned the task. By the time he got around to it, the weeds were 3 inches tall. Corn was coming up puny. It was enough to make one shudder. Physical management mistakes can undo everything.

Smartweed can be an indicator of nutritional stress.

These few observations from the field already suggest that the topic of weeds is a very complex subject. The best weed manual in the world can only hint at solutions to the many problems related to weeds. Unfortunately, those who have taken the weed situation by the nape of the neck and the seat of the pants over the past fifty years have done little more than shake out poisons, not results. Here our objective is to establish a positive viewpoint so that we can analyze what weeds are and accept the Creator’s plan while we appreciate the romance of the tribe.

A Brief Glance at Weed Varieties

There are many mansions in the house of weeds. For example, there are swamp weeds, the cattails and the rushes. There are desert weeds. There are weeds that grow in sand and weeds that grow in silt, and there are weeds that grow in gumbo so tight it resembles modeling clay. Foxtails grow in gumbo, but they also grow in sand when such soils are out of balance and the electrical tension on soil particles is so tight that even sand can build clods and restrict air in the soil enough to set free the hormone process that wakes up foxtail seeds.

There are subsoil weeds. There are weeds that grow in acid conditions and — in the West — there are weeds that like alkaline conditions. Up in Wisconsin and Minnesota there is a weed called “devil’s paint brush” by the locals. This one joins the daisy in having a love affair with sour soils.

Almost always, such soils have an excess of iron and flush out a lot of trace minerals and rock minerals that support the hormone processes that give permission to live for these weed species. It is impossible to grow a high yielding crop when such conditions prevail. It is possible to grow red clover, mammoth clover instead of alfalfa because alfalfa simply won’t have much of a chance as a quality foliage crop.

There are sour soils, neutral soils, alkaline soils and salty soils, and there are weeds that identify with all of these conditions. There are weeds that relate to wet soils and weeds that embrace hot conditions and others that like colder conditions. The degree of sunshine and the length of day and night figure in nature’s equation.

There are weeds that get a head start on the farmer and those that emerge only after the farmer has done his job. All of these weeds have a biography and all seem to share their prophecy with those who look and actually see.

Take rotten weeds, weeds that actually exhibit rotting conditions in the soil. Take stinky weeds and fungal weeds. All reflect the sour, sick, dead excess toxic level of soil components.

There are even herbicide indicator weeds, weeds that grow too well after an accumulation of a certain level of herbicides, usually over several years. Such weeds build up a negative effect on the desirable biological things that have to happen if crop production is to be successful. These weeds tell the United States Department of Agriculture that a measure of madness is afloat when spokesmen make their annual pronouncement that without herbicides and chemicals fifty million U.S. citizens would starve.

There is a damning finality to the evidence that has piled up since Acres U.S.A. began publication twenty-five years ago, because this evidence proves that soils subjected to herbicide use year after year have now achieved a negative depressing effect and gifted degeneration to the soil system, with resultant shortfalls in crop yields. Once such soils are cleansed of herbicide residues, yields can be increased as much as 50 to 75% without the addition of more fertilizer inputs. Moreover, once these soil conditions are corrected, there is a chance to manage the weeds without the use of toxic genetic chemicals.

Every weed, generally within twenty-four to forty-eight hours after germination, has the ability to emit auxins. These are growth factors that come off the seed via rootlets and penetrate out into the soil, sometimes as much as a half-inch from the seed itself. That auxin tells every other species in the immediate neighborhood to stay asleep.

There are hundreds and thousands of seeds in every square foot of soil, and yet only so many germinate and grow each year. They seem to know better than to crowd each other out. Another year, other seeds get their chance. There are enough seed deposits in most soils to last fifty, one hundred, even five hundred years, and some seeds live that long. As long as the chemistry and biology and environmental conditions are there, certain species will wait. The dust storms did not annihilate the tumbleweed seeds or terminate the prickly pear, and all the laws passed to proscribe noxious weeds or prevent seed transport from farm to farm, county to county or state to state are merely so many monuments to the stupidity of man.

Crop Planting and Non-Toxic Weed Management

There is a lesson in all this. As the weed seed germinates, it emits those growth factors. Astute farmers can use weeds to their benefit.

In the spring, when preparing the rootbed, watch the warming and the curing and the ripening and the germinating capacity of the soil system being established. Always, certain weed seeds will start to germinate. The day that you go out and scratch the soil and see germinated weeds with roots about an inch long, that is the time to change the concentration of carbon dioxide and oxygen in the rootbed, and place the desired crop seed.

Within the first twenty-four hours that little weed seed has done its job. It has given off auxins enough to dormatize every other weed seed next to it. It is nature’s form of population control. It just allows certain weed seeds to come alive and stake out a proper domain, meaning space to ensure enough light, air, drainage, ventilation and carbon dioxide to prosper and produce new seed, the Creator’s purpose for a plant.

At the stage of its growth when it germinates, that little weed seed is very susceptible to dying. It can be killed easily simply by taking light tillage equipment through the soil to change the oxygen content. Cation balance, pH, the phosphate level, moisture, air — all determine how long an auxin system will endure in the seedbed. Soils that are completely dead and have no biological capacity, no balance, no equilibrium, soils abused to death with hard chemistry or imbalanced inputs of salt fertilizers, make it possible for the weed crop to hit the ground running, so to speak.

Auxins from weeds can endure in the soil for as long as six to eight weeks. Unfortunately, in most soils managed under the precepts of mainline agriculture, crop auxins can endure only three or four days. That is why partial and imbalanced fertilization usually becomes a sales ticket for insurance spraying, a benchmark for the chemical amateur.

Wild Mustard
Wild mustard is usually related to a field planted to small grains and the development of slime molds. The weed grows best in areas stressed due to poor drainage and poor structure. Control comes down to applying good compost or nitrogen to get the decay process moving properly. Above, an artist’s conception of pinnatifida variety (A); the seedling (B); a flower (C); siliques, an elongated fruit divided by a partition between the two carpels in two sections (D); and seeds (E).

Thus the equilibrium established in the soil determines how long growth factors can endure and exercise a dormatizing effect on a crop of weeds. If good biological management gives the crop seed time enough to send out its hormones and say, I command power over this domain for this generation, weeds cease to be the grower’s boogeyman and coffee klatch excuse for bad farming.

No one need accept my word for this. As Rudolf Steiner often said, “Experiment, experiment!’’ Almost every corn grower finds that certain rows were missed or that there are gaps in certain rows. The instant impulse is to replant, sometimes one seed at a time. But it never comes to anything. The new and later plants lack vigor and seem deprived of the potential they ought to have. The reason is simple. The other rows out there have already taken command over that soil domain and do everything they can to shut down the come-lately arrivals. They have sent their hormones out into the soil, and injected a negative effect for the replants to field.

That is why it is necessary when planting any seed crop to control the depth of planting and the spacing of the seed, so that they all come up on equal footing.

Any seed that germinates one or two or four days later than the seed placed next to it never has the potential for producing a high-yielding, field-ripened harvest. Weeds have the most serious effect on crop production during the first week or ten days of their life. That is why a small weed, one only a half inch above the surface of the soil, has such negative effect on the yield and quality of the crop.

C.J. Fenzau, my consultant for An Acres U.S.A. Primer, was so adamant on this point he sometimes repeated it several times in the same conversation. “We must control weeds in the early stages,’’ he would say. “Once the crop is this tall [indicating a foot or more] and a few weeds arrive underneath, they aren’t going to have much of a chance to do a lot of damage.’’

The Bottom Line on Weeds

Across more counties than most people see in a lifetime, this has been the lesson I learned “watching crops grow.’’ You can live with these weeds because they have less effect on yield and quality than when the corn crop is emerging from the soil with weeds arriving at the same time. In theory some of the pre-emergent herbicides set up this condition, but their legacy of damage is worse than the problem they presume to solve.

The bottom line is simply that good soil structure, good soil drainage and good aeration can control biological activity in the soil. In turn, the farmer can increase the nutrient supply and grow a high-yield crop even if a few weeds are supported underneath. But a sick soil with inadequate nutrient release and conversion will have a depressing effect on the yield potential. This allows the weeds to have a more negative effect simply because there are not enough nutrients to feed both the desired crop and the weeds. It also allows weeds to impose water limitations.

Weeds can set up severe competition for water, plant nutrients, air and light. If a crop is dominating and restricting the amount of light, then the light that filters through to the weeds underneath is subdued. Thus the weed is not able to grow as fast as its programmed genetic potential might otherwise allow. Instead of having a fat stemmed plant with a lot of root capacity, it is restricted because it failed to get enough light, and thus becomes a weak, thin-stemmed plant, one with smaller heads.

Any farm reporter who travels from one end of the country to the next can observe how weeds reflect reasonable variables such as altitude, sea level conditions, the amount of light and the angle at which the sun is exposed to that part of the earth. All these things have a bearing on establishing the character and the form and the potential of various weeds. You see some weeds that are short and blocky and thick-stemmed with great leaves, and others that are tall with thin stems and small leaves. These are all reflections of growing conditions. That is why weeds are an indicator of the limitations that exist. Farmers who learn how to read them find that this knowledge confers an ability to make better management decisions on how to live with weeds and still grow a good crop.

Source: Weeds—Control Without Poison