Mole Control: DIY Trap Construction

Mole control methods range the gamut from simple and non-toxic to chemical-based and complex. My simple mole trap was founded on the basis of field trials and personal convictions I hold regarding the environment and its inhabitants. Prior research had been done early on in the search for a humane and sustainable method for dealing with the mole problem here at Highland Hill Farm.

Highland Hill Farm is a 22-acre parcel located in the steep, rocky foothills of Mt. Sunapee. Agriculturally speaking, this area of New Hampshire is better suited for grazing pasture and forestry than for large-scale horticulture. A milestone in sustainability and independence here on the farm has been reached with the addition of a fully functioning, off-grid solar powered electrical system. Photovoltaic solar panels supply clean renewable power to maintain three farmstead dwellings as well as the two large chest freezers used to keep the summer produce fresh. This system was designed, constructed and fully funded by myself as a personal goal to act responsibly in support of the convictions I maintain toward environmental stewardship.

This article was written on a computer powered by the sun. I developed and experimented with various types of mole traps. The soil of my growing beds is rich and teeming with life, especially earthworms, the favorite food of the common northern mole (Talpa europaea ). Over the years I’ve been using a thick layer of mulch hay between the rows and around the spring plantings. This layer of hay provides cover for the moles, and as it decomposes it provides food for the earthworms. Plenty of worms create an environment conducive to plenty of moles. It’s not uncommon for me to step on a mole tunnel every third or fourth step, even around the grassy area near the trout pond. The infestation had gotten to the point where action had to be taken.

Moles undermine the root systems of plants, damaging the plants and making irrigation and nutrient up-take much more difficult. I believe the live trapping methods I’ve been developing have merit in helping farmers eradicate moles in an environmentally sound way, without toxic poisons or mechanical traps. I will continue to develop inexpensive, effective live mole traps through field trials at various farm locations throughout the area. The opportunity to develop new methods and designs may have crossover potential for other rodent pests.

mole trap
This trap is made from a common five-gallon bucket with about 70 quarter-inch holes drilled through the bottom.

Poisonous Bait

The main thrust of the commercial market relating to rodent eradication is focused on poisonous bait. Motomco Mole Killer claims, “one worm contains a lethal dose.” Unfortunately, the poisoned mole may become the prey of another unintended victim of the poisoned bait. This product is “not to be sold in AK, HI, NC and NY.” Another poison-based product, Moletox claims, “This exclusive formula pelleted bait has a unique cracked corn base, making it more palatable.” The problem here is that moles are exclusively carnivores/insectivores and would have no interest in cracked corn. This product is “not to be sold in CA, IN, NC, NH and Washington D.C.”

Clearly poisons should be an absolute last resort rather than a first choice.

Mechanical Traps

Mechanical traps offer a considerable advantage over poisons as far as environmental impacts are concerned. Most mechanical mole traps are designed to either impale or squeeze a mole, one at a time rendering the trap ineffective until it gets reset.

These traps are spring-loaded and come with their own warnings. The “innovative new scissor trap” is not to be sold in Alaska, Hawaii or North Carolina. These traps must be set over an active mole tunnel (of which there are many to choose from) and require a lot of vigilance on the part of the trapper. Here the trapper is going to spend a considerable amount of time chasing the moles, hit or miss, around the field in order to eradicate but a few.

Mole Control: Organic Mole Eradication

I had been on the search for a natural or organic method of mole eradication and have viewed many websites in a quest for a somewhat humane mole trap. The “sticky” trap seemed the best, consisting of a wide tape-like sheet that the moles were supposed to get stuck to. I made one but caught none. I’ve discovered moles are quite clever — they will test something and if they don’t like it after trying it once, they’ll stay away from it. Besides, there was no incentive for the moles to cut across the sticky sheet, no food, no reward, just a shortcut.

The mulch hay I lay over the bare soil each spring protects the microbial life-forms on the soil surface from solar UV rays that would otherwise sterilize the soil surface, killing that rich, vibrant biomass. Nature does her best to cover over bare soil with biomass in order to protect soil life-forms to keep them alive, protected from UV and erosion-proof.

I like using the mulch hay method because it is constantly building soil. The hay method also prevents compaction because the weight of man or equipment is distributed over the wider surface area of a thick hay mat. The mulch also holds in a lot of otherwise evaporated water and prevents erosion during a downpour.

During midday if I pull back some of the hay, earthworms will be on the surface of the soil. Earthworm castings and the soil-enriching properties of their activity are beneficial to soil conditions and therefore beneficial to the crops that the soil supports.

Star-nosed and common Eastern moles.

If a farmer has a lot of earthworms and some loose hay on the ground chances are that he/she will also have a host of moles tunneling about. The benefits of using mulch hay far outweigh discontinuing the practice due to the mole problem, but they are a problem nonetheless. I was transplanting small lettuce plants from an outside raised bed into the winter greenhouse. The raised bed lettuce was riddled with sub-surface tunnels to the extent that I was able to remove large swaths of young plants simply by running my hands through the soil 2 to 3 inches under the surface, nearly unobstructed, plowing from one tunnel into the next.

This was an advantage in transplanting, but in my other greenhouse where spinach was planted in raised beds the plants were stunted and sparse because of mole activity. Mole activity necessitates more frequent watering due to the fact that sub-surface tunneling dries the soil much faster. Safely trapping and removing the moles from the greenhouses and growing beds will increase production of both crop plants and earthworm populations.

The trapping methods I’ve employed so far have consisted of several trap designs and various baits. One design in particular has shown promise over previous ideas. The primarily successful live trap now in place on my farm has trapped as many as four moles in the same trap over a three-day cycle, indicating that this method could potentially serve to trap many more live moles over a longer period, therefore alleviating the tedious chore of checking multiple mechanical traps every day or even every three or four days.

Moles consume nearly their own weight in food each day. Moles are from a group of mammals called insectivores. This live-capture study may also prove useful in that moles could possibly be used in areas of insect infestation to remove problem insects, then recaptured live and relocated for use at other sites.

Moles have several other distinct features that may prove useful in further studies. Moles produce a toxin in their saliva that incapacitates earthworms, and moles have a high blood oxygen content. I believe these two features of the anatomy of moles are worthy of a great deal of study. Live capture could possibly be a very positive offshoot of this live trapping method in order to supply research labs.

At this time live moles are released into the wild a fair distance from the trap locations. The experience of dealing with an infestation of destructive mole activity on my farm led to the search for a nonpoisonous, non-violent, inexpensive and effective method of eradicating moles.

Through my own experimentation and expressions of ideas I’ve come up with a mole trap that works reasonably well, has no environmentally harmful side effects and is economically viable for just about anyone, anywhere. The trapping method described has been put to use here over the last few months of this past growing season and I have documented its simplicity and effectiveness.

Mole Control: Preparing the Trap

This study was a comparison between the various trap designs that resulted from my experiment and used in combinations of live baits. No commercial traps or poisons were used. The best bait was local — earthworms on the farm were dug up and refrigerated for future use. The traps are simple to construct using a common 5-gallon pail that is clean and odor-free. A pail that has been open and set outside for a while or one used for garden water and soil will work well. Drill about 70 quarter-inch holes through the bottom to allow water to move through and to give the mole a sense of openness below.

Locate the area most heavily infested for installation. Dig a hole that will loosely accommodate the bucket with plenty of room around the sides to be backfilled with loose soil. Set the bucket in about 3 inches deeper than the bucket open top so that the fill soil slopes downward around the open rim. Now fill about 25 to 30 percent of the bucket with rich, loose soil. Get a separate container for your live worms and place just enough soil in to keep the worms alive but not allow escape. Six to eight worms are plenty and should last three to four days. Depress the worm container into the rich bucket soil to keep it at ground temperature and the worms alive. While installing your trap it is helpful to stand on top of boards in order to prevent compaction. Moles commonly reuse the same tunnels so try to leave them undisturbed. Place a generous layer of mulch hay around your trap and cover with a piece of board that has been outside for a while. Your trap is set.

If you leave the trap unchecked for three days you may have a better success rate than if you check more often. There will be less human presence sensed by the moles, and if there are some moles already in the trap, more are likely to join the festive party. Always wear gloves to prevent human odors around the trap and to protect your skin from wily moles.

The design intent for these trapping materials and methods involves materials that are available and common to most every area of the world. The design is simple to build and install at a very low cost to the farmer, involving no special tooling or hard-to-find materials. The design does not require the purchase of mechanical devices or commercial poisons.

The intent is to produce a replicable trap for mole control that can be constructed and installed by the average farmer using materials commonly found on any farm. Aspects of agricultural sustainability are addressed by the ability of the farmer to be able to build his own traps from simple materials and bait them with worms or insects that are found on the farm.

This study focused primarily on star-nosed moles and the European mole, also known as the common mole or northern mole, common to this Northeast region. Northeastern farmers who have mole infestation problems will most likely be dealing with these species, and the trapping methods should work equally well throughout the region and beyond. The simple trap designed and used here has proven to be successful in trapping moles. This method is easily transferable — the most successful design/bait combination is available to farmers everywhere. It seems likely this simple trap could work successfully for mole control most anywhere in the world.

By David Brown. This article was originally published in the September 2013 issue of Acres U.S.A. magazine.

Aphid Control: Lady Beetle as Beneficial Insect

By Dr. Ayanava Majumdar

When searching for aphid control measures, turn to nature first. Numerous vendors sell beneficial insects via their websites along with offering plenty of useful information. For example, ARBICO Organics (Arizona), Orcon (California), Gardens Alive (Indiana), and Nature’s Control (Oregon) sell insect predators in large numbers and at least one vendor sells it as a “beneficial insect program” with weekly shipments adjusted to your pest control needs. Note that beneficial insects are slow acting in pest outbreak situations, so use beneficial insects preventively when pests are in low populations and have not overwhelmed the crops you are trying to protect. Follow the release instructions that come with the products, and modify your spray schedule to adjust for the presence of beneficial insects.

Aphid Control: Convergent Lady Beetle

The convergent lady beetle is a very common species of lady beetle among the numerous others present in any crop field. The convergent beetle is common in Alabama and also a very popular beneficial insect sold by companies. The insect name comes from the two white lines seen on the thorax of adult beetles that seem to merge together on the top.

ladybug
The convergent lady beetle is a common species of lady beetle.

The number of dots can vary from none up to 13, so counting the dots alone is not a good identifier for this beetle. Larvae are black with rows of orange spots. Note that the lady beetle larva have chewing mouthparts and do not have the sickle shaped mandibles of the green lacewing larva. Eggs are elliptical and bright yellow in color; eggs are laid in clusters on plants with over 10 eggs per cluster. Eggs can also be laid in soil or plant debris. Pupae are immobile (non-feeding stage) and may be seen stuck to plant parts.

Adults and larvae feed on aphids. Adult beetles also feed on nectar and pollen. According to industry sources, each adult lady beetle can destroy about 5,000 aphids while the larvae can consume nearly 400 aphids in a week. In the absence of aphids, convergent beetles can also feed on moth eggs and small caterpillars. Female convergent beetles lay up to 1,000 eggs in ideal conditions and have a lifespan of one to three months. Larvae feed for three weeks and adults emerge two to five days after pupation.

Adults do not fly if air temperatures are below 55°F. There can be many generations of this insect every year.

lady bugs beneficial insects

The presence of a large number of lady beetles can indicate the presence of aphids. This insect can be the most abundant predator in cotton fields.

Many suppliers sell lady beetles in the adult stage when they are ready for field release (as shown in photo). The adult beetles can also be stored in their original package for some duration; provide some moisture to the lady beetles by sprinkling water on the packaging before release. Release lady beetles preferably during a cool evening. Lady beetles should be released when pest pressures are low and the beetles have something to feed on. Several weekly releases may be necessary to sustain a high predator pressure in an area. Industry sources recommend the release rate of 4,500 beetles for 2,500 square feet and much larger numbers for large areas. Out migration of adults once prey numbers dwindle is a major cause of loss of these powerful natural control agents.

Routine inundative release of beetles in large numbers can be effective in enclosed structures for aphid control. Remember that parasitoids and pathogens also act in conjunction with predators to provide natural control of pests. Do your own research before purchasing large batches of predators and carefully plan the release for the best effect. Follow the instructions that come with your purchase of beneficial insects.

Providing cover crops or shelter plants during the fall season is a good way to facilitate continuity of predators in an area.

Editor’s Note: This article appeared in the November 2012 issue of Acres U.S.A.

Dr. Ayanava Majumdar (Dr. A) is extension entomologist and state sustainable agricultural research coordinator at Auburn University, Alabama. Join him on the Alabama Vegetable IPM Facebook page for more information on sustainable crop production systems. 

Foliar Feeding Organic Herbicides & Pesticides for Soybeans

By Dr. Harold Willis

Foliar feeding is a complex subject that cannot be covered thoroughly here, but in general it allows you to supply small amounts of deficient elements to plants (through their leaves, primarily) at the time they need them.

Fertilizers applied to the soil before planting may not be available to the plants when they need them most—during peak growth and pod fill. Foliar spraying is not an effective way to deliver large amounts of major nutrients (so it is best to have them in your soil already), but it can help pull your crop through a difficult period and produce a good yield. Foliar spraying will often stimulate the plant to take up more of the soil’s nutrients.

soybean symptoms

Ordinary field sprayers do not produce a very fine spray, so they waste a lot of material. Better sprayers homogenize or atomize the spray, allowing you to spray a field for only cents per acre in some cases. You can mix your own tailor-made spray mixture with a little experience, depending on what your plants need at that time.

A good “all-purpose” spray is a mixture of about 6 quarts liquid (emulsified) fish and 2 quarts seaweed, diluted in 100 gallons of water (deionized or soft water is best). The fish and seaweed mixture should be acid (pH 5-6.5); this can be done by first adding from 1 pint to 2 quarts of liquid phosphoric acid to the 100 gallons of water. The liquid fish should be strained to keep from plugging your sprayer. Spray at the rate of 1 quart of the mixture per acre if you have a homogenizing sprayer, or until plants are wet.

Another spray mixture for young soybeans when soil fertility is low (low calcium and phosphorus, especially) is as follows: add in this order to 100 gallons water, (1) up to 2 gallons of 9% ammonia solution (or household ammonia); (2) up to 2 quarts liquid phosphoric acid (available from feed dealers or pharmacies); (3) 1-2 pounds of iron sulfate (dissolve first in warm water); (4) 5 pounds of soft rock phosphate (stir into a container of water and skim off and use the white, milky water above the mineral); and (5) 1 pound potassium sulfate (or 8 ounces potassium hydroxide). Spray at a rate of 7 gallons per acre, or until plants are wet.

If older soybeans have blossoms falling off and failing to set seeds (some will do this anyway), a spray mixture that may help contains the following in 100 gallons of water: (1) up to 2 quarts liquid phosphoric acid; (2) 1-2 gallons ammonia solution; (3) 1-2 pounds iron sulfate (dissolve first in warm water); (4) up to 8 ounces manganese sulfate; (5) 5 pounds soft rock phosphate (stir into a container of water and use milky water); and (6) 1 quart emulsified oil (crop oil, dormant oil). Spray at 7 gallons per acre, or until plants are wet. Additional sprayings may be needed at one-week intervals; if so, use ingredients at one-half strength and eliminate the emulsified oil.

Even after soybeans are older and filling seeds, yield can sometimes be increased by using a fish emulsion spray (2 gallons fish per 100 gallons water; spray until plants are wet). Do not use fish sprays after two weeks before cutting if the crop is for hay or forage, since animals do not like the taste.

Many proprietary brands of biologicals suitable for spraying are now on the market, and are advertised in Acres U.S.A.

Drone spraying soybeans
New technology offers farmers even more ways to effectively care for their crops!

Researchers at Iowa State University developed a foliar spray mixture that increased yield substantially when sprayed after pod set, since at that time root nodules begin to die and disintegrate. Their spray contained nitrogen, phosphorus, potassium and sulfur in the ratio 10:1:3:0.5. The fertilizer source materials they used were urea, a 3-20-18 formulation containing polyphosphate, and potassium sulfate or ammonium sulfate. Some sprays also contained 5% sugar. When tested by researchers in other states, results were disappointing, possibly because of soil imbalances. Most observers expected the Iowa State program to fail because it cost too much, and because the preparations were in danger of burning the plants.

Feeding foliar sprays through an irrigation system is an effective method of application if you are able to do this.

The best times to spray are in foggy weather or in the early morning (4:00 to 6:00 a.m.), since this is when the plants take in nutrients best. The evening (after 7:00 p.m.) is another good time to spray. Be certain your sprayer has no traces of herbicides or pesticides. Clean thoroughly with baking soda solution. You can test to see whether the spray mixture is going to help your crop if you spray several plants with a small hand sprayer (such as used with window-cleaning products). Wait a half hour and then test the sugar content of sprayed plants with a refractometer compared to unsprayed plants. If the sugar content increased, the mixture is beneficial.

Spray with Hydrogen Peroxide

An interesting development on the eco-agriculture scene is the use of hydrogen peroxide, H2O2, in a variety of ways. When added to animals’ drinking water in diluted amounts (about 30 parts hydrogen peroxide per one million parts water; or about 8-10 oz. of 35% hydrogen peroxide [or 3 quarts of 3% hydrogen peroxide] in 1000 gallons of water), the incidence of disease and sickness drops dramatically, from pneumonia to mastitis. Meat and milk production rise. Hydrogen peroxide solution can also be used to drench animals, as an udder wash, and to rinse dairy pipelines and bulk tanks. In animal (or human) use, it appears to act by providing more oxygen to internal tissues (hydrogen peroxide is basically water, H2O, with an extra oxygen atom, H2O2). Externally it also acts as a disinfectant, killing germs.
But hydrogen peroxide also helps plants grow better, although the mechanism is not clear. If seeds are soaked in a hydrogen peroxide solution (1 to 5 oz. of 3% hydrogen peroxide in 1 pint water or ½ to 2 oz. of 35% hydrogen peroxide in 2 quarts water) for about 8 hours, the percent germination should increase (germinating seeds need oxygen).

For a foliar spray to perk up growing plants, use 1 pint of 35% hydrogen peroxide (or 11 pints of 3% hydrogen peroxide) in 20 gallons of water to spray one acre.

Hydrogen peroxide also makes an effective insect spray. Use at a rate of about ½ pint of 3% hydrogen peroxide (or 1 oz. of 35% hydrogen peroxide) along with ½ pint of molasses per gallon of
water (equal to about 6 gallons of 3% hydrogen peroxide [or 5 pints of 35% hydrogen peroxide] and 6 gallons of molasses per 100 gallons water). The molasses helps the solution stick to the plants and also gums up small insects. What drips onto the ground will help the plants grow better, too.

The preferred form of hydrogen peroxide is 35%, or food grade. It is harder to get than the 3% solution sold in grocery and drug stores. The latter has small amounts of preservative chemicals added, but they may not be harmful when used on plants.

Source: How to Grow Super Soybeans

How to Solve Common Soybean Problems

By Dr. Harold Willis

Agriculture tends to be full of unpleasant surprises. Things seldom seem to go right. The weather doesn’t cooperate—too wet, too dry, too hot, too cold. Weeds, pests, diseases, all proliferate. Most of these problems seem beyond the farmer’s control, but there are things you can do to largely prevent or overcome most of the things that go wrong. The following is a list of common problems seen with soybeans, and how to solve them.

Emergence

The first problem likely to strike soybeans is difficulty for the seedling to break through a surface crust. This is an emergency, and you should break the crust immediately with a rotary hoe or cultivator. Driving on emerging soybeans will not significantly reduce stands. The problem can be prevented by getting good soil structure so that crusting will not occur. This can be done by adding compost or light amounts of manure or poultry litter to the soil; that is, increase the soil’s organic matter content. The organic matter should be worked into the upper several inches of soil.

common soybean problems - a healthy soybean
Healthy soybeans depend on healthy soil.

Weeds

Weeds compete with soybeans for moisture, soil nutrients and sunlight, reducing yield. They can also interfere with harvesting, and their seeds contaminate harvested soybean seed. Weeds should be controlled if the probable yield loss (dollar loss) exceeds the cost of control. Weeds can be controlled by management, mechanical and chemical control. Chemical control is rapidly becoming less an option. Heads-up bio-farmers feel themselves secure in the knowledge that weed control is based on fertility management, and not in buying a more powerful poison from Dow Chemical or Monsanto.

For weeds that have germinated, control must be made within the first four weeks after soybean emergence to prevent yield reduction. Weeds that emerge after six weeks will have little effect on yield. Weeds growing before planting should be killed by seedbed preparation tillage. Soybean seeds should have good soil-seed contact to get the seedlings off to a rapid start so that the soybean foliage will shade out weeds.

Deep-planted seedlings grow more slowly than shallow-planted ones. Leaving a rough between-row seedbed will slow down weeds. Narrow rows allow soybeans to shade out weeds more quickly.

Before soybeans are one inch high, rotary hoeing is an effective method of killing emerging weeds. It works best at relatively high speeds (8 to 12 miles per hour) late in the day when soybean seedlings are less brittle. A shovel cultivator is effective on small or larger weeds when soybean seedlings are a little larger. Shovels should be set at a shallow depth (1 to 2 inches) to reduce pruning of soybean roots. A rolling cultivator can also be used effectively for small weeds when operated at 6 to 10 miles per hour. These mechanical methods cannot be used in narrow-row or solid seeded stands.

The use of herbicides to control weeds in soybeans has grown gradually since World War II, and is now both questioned and under fire. Newer, more powerful herbicides have been developed. Some kill broadleaf weeds, others grasses. Some are applied before planting, others after soybean emergence. Some are incorporated into the soil, others are surface-applied. Some are more toxic than others, but they are all designed to kill living plants and thus should be used with great care if used at all. The Acres U.S.A. position is that they do not belong in a sound management program. Many problems can arise, including killing (or damaging) soybean seedlings, spray drift into unwanted areas, carryover into succeeding years, toxicity to beneficial soil organisms, and human or animal toxicity. Since most weeds can be eliminated by having healthy, balanced soil, herbicide use should be unnecessary.

Most of the weeds afflicting soybean growers prefer to grow in poor, out-of-balance, waterlogged or poorly aerated soil. These include quackgrass, giant foxtail, Johnsongrass, smartweed, bindweed and velvetleaf. I know it will be hard for some to believe, but the above weeds, and many others, grow best in “sick” soil; in healthy, balanced, well aerated soil, they grow poorly or not at all. A 2:1 phosphate to potassium ratio (as shown on water-soluble soil tests) will help eliminate weeds. Only a few weeds grow well on good soil. These include lamb’s quarters and redroot (rough) pigweed. Milkweed, purslane and cocklebur grow well on fairly good soil.

Diseases

About 50 diseases attack soybeans in the U.S. with viruses, bacteria, fungi and nematodes (roundworms) being involved as pathogens. There are seed and seedling diseases, root diseases, stem and leaf diseases. Some can cause serious yield or quality losses, whereas others cause little problem. The worst are the fungal Phytophthora rot and the root knot nematode. Some varieties are resistant to these two diseases.

The thing about diseases is that they only attack plants that are already under stress. That is what really causes the disease. The so-called pathogens—bacteria, fungi, worms—then move in to destroy the sick and unfit plant. Nonsensically, we treat the symptoms and spray toxic chemicals to kill the pathogens and save the sick, poor quality crop. (Unfortunately farmers feel they have to do this to survive in farming today.)

The simple solution to crop diseases is this: healthy, vigorous plants growing in good, balanced soil don’t get sick. They have the ability to resist disease pathogens in much the same way as our bodies resist germs, as long as we eat right, get plenty of rest and exercise, and avoid stress. Plants often resist diseases by producing substances that prevent pathogens from growing; some of these are called phytoalexins.

Of course, the way to grow healthy plants is to have fertile soil with good structure. As we have mentioned earlier, this means well aerated, loose soil with high levels of humus and beneficial soil organisms, and high, balanced levels of nutrients (high calcium is essential for disease resistance, for example). Some of the beneficial soil organisms actually protect a plant’s roots from pathogenic bacteria, fungi and nematodes. Others channel nutrients and water into the roots, helping the plant to grow.

If your soil is in good shape, the only other stresses that could affect the plant are from adverse weather. But even here, good soil can counteract most weather stresses. Loose, well drained soil will soak up heavy rain. Humus holds water in drought conditions, and the sticky secretions of soil microbes also help drought-proof soil. Friable soil will not crust and will allow plenty of air to reach roots and nitrogen-fixing bacteria. Most disease pathogens cannot live in well-aerated soil.

Pests

The story about soybean pests is about the same as for diseases and weeds. Many species of insects and mites will attack soybeans, although only a few cause economically serious damage. Some eat seeds and roots, others attack stems, leaves or pods. Some chew, while others suck juices. Again, the scientists come to the rescue by spraying toxic chemicals (and a farmer may feel he has to resort to that technology to save a crop), but again, the simple solution is the same—healthy, vigorous plants growing in good soil. Such plants are naturally immune or resistant to pest attack. The pests either avoid the plant altogether or else just take a few nibbles and then go away. As with herbicides, toxic fungicides, insecticides, and other pesticides, their use should become unnecessary after ecological farming principles have been used for a year or two.

Nutrient Deficiencies

If a plant is not getting the proper amounts of nutrient elements, it may develop certain symptoms, abnormal colors or growth deformities. By the time these symptoms appear, it is often too late to do much to alleviate the problem (unless plants are still small or you can foliar feed them), but you can try to trace the cause and overcome it for the future.

Nutrient deficiency symptoms may not necessarily mean one or more elements are deficient in the soil. The nutrient may be adequate but the plant may not be able to take it up, perhaps because of high or low pH, or too much or too little of some other soil element. Or perhaps stress on the plant from drought, wet soil, cold weather or toxic soil conditions causes roots not to absorb the element. Nutrient deficiency symptoms in soybeans are listed in the accompanying box.

soybean symptoms

Sick Root Nodules

Healthy, active nitrogen-fixing root nodules will have a pink or reddish internal color. You should monitor the health of these furnishers of free nitrogen by occasionally digging up a plant and examining its root nodules. They should be abundant and pink when cut open. If the nodules are few in number or greenish or yellowish inside, something is wrong in the soil. Perhaps there are toxic substances (from pesticides or too much raw organic matter) in the soil which are harming the bacteria.

Perhaps the soil is poorly aerated, since nitrogen-fixing bacteria need oxygen and nitrogen from the air. Perhaps there is a molybdenum deficiency or low pH (acid). Perhaps the soil already has plenty of nitrogen, either from past fertilizers or from heavy manure application (this is not necessarily a problem, however). Sick root nodules are just one more symptom that you may be able to use to trace down and solve a problem.

Foliar Feeding

If your soybeans seem to be lagging in growth or standing still, perhaps because of weather stress (cool, cloudy weather), you may be able to give them a “shot in the arm” and pull them out of it. With a high value crop such as soybeans, it may be economically feasible to foliar feed to help the plants along.

Source: How to Grow Super Soybeans

Signs of Nutrient Deficiencies in Soybeans

By Dr. Harold Willis & Neal Kinsey

If a plant is not getting the proper amounts of nutrient elements, it may develop certain symptoms, abnormal colors or growth defor­mities. By the time these symptoms appear, it is often too late to do much to alleviate the problem (unless plants are still small or you can foliar feed them), but you can try to trace the cause and overcome it for the future.

Nutrient deficiency symptoms may not necessarily mean one or more elements are deficient in the soil. The nutrient may be adequate but the plant may not be able to take it up, perhaps because of high or low pH, or too much or too little of some other soil element. Or perhaps stress on the plant from drought, wet soil, cold weather or toxic soil conditions causes roots not to absorb the element. Nutrient deficiency symptoms in soybeans are listed below.

Potential problems with fertilizers

Using commercial fertilizers that are toxic or that cause nutrient imbal­ance can lead to poor soil structure and weed problems. In addition, highly soluble fertilizers leave excess soluble nutrients to fertilize the weeds.

Types of fertilizers used and careful placement can greatly reduce the fertilization of weeds. Anhydrous ammonia and fertilizers that release high amounts of ammonia (solid urea and diammonium phosphate, or DAP) can kill crop seedlings and cause worsening soil conditions (acidity, loss of humus and denser soil). High-salt fertilizers such as muriate of potash (or Kalium potash) can also injure seedlings and cause salt build-up which may favor weeds.

leaf analysis
Examining foliar health could give you the clues you need to find which nutrients and minerals are deficient, or in too much abundance.

Soil life is beneficial

Encourage a high earthworm population. With their tunneling and production of casts, earthworms can eliminate com­paction and increase granulation of soil. They need a supply of fresh organic matter (manure, crop residues, etc.) for food and as little distur­bance as possible from tillage (at least until their population builds up).

Other beneficial soil life also helps improve soil structure — the micro­scopic bacteria and fungi that decompose organic matter. They need aer­ated soil and occasional additions of raw organic matter for food. Usually if earthworms are common, the microscopic organisms will be too. Earthworms often eat weed seeds and either destroy them or lower their germination capability. Some weed seeds may be destroyed by microor­ganisms. Composting manure or other materials is a good way to kill weed seeds.

Mineral deficiency symptoms in soybeans

(from Modern Soybean Production, 1983, p. 171-73)

  • Nitrogen. Pale green or yellowish leaves. Seldom a problem if root nodule bacteria are present. Can be due to a molybdenum deficiency.
  • Phosphorus. Plants stunted; leaves blue-green and sometimes cupped.
  • Potassium. Irregular yellow border around leaves.
  • Calcium. Few nitrogen-fixing root nodules, causing nitrogen deficiency symptoms.
  • Magnesium. Leaves turning yellow or brown between veins; leaf tip curled down.
  • Sulfur. Slow growth; leaves becoming yellowish.
  • Iron. Slow growth; new leaves yellow or brown between veins.
  • Manganese. Leaves light green to white between veins.
  • Molybdenum. Reduced growth; leaves with nitrogen deficiency symptoms.
  • Zinc. Plants stunted; lower leaves turning yellow to brown to gray and dropping off; young plants with pale green leaves. Few flowers and pods; pods mature slowly.

Sick Root Nodules

Healthy, active nitrogen-fixing root nodules will have a pink or reddish internal color. You should monitor the health of these furnishers of free nitrogen by occasionally digging up a plant and examining its root nodules. They should be abundant and pink when cut open (until the plant begins its period of senescence). If the nodules are few in number or greenish or yellowish inside, something is wrong in the soil. Perhaps there are toxic substances (from pesticides or too much raw organic matter) in the soil which are harming the bacteria. Perhaps the soil is poorly aerated, since nitrogen-fixing bacteria need oxygen and nitrogen from the air. Perhaps there is a molybdenum deficiency or low pH (acid).

Perhaps the soil already has plenty of nitrogen, either from past fertilizers or from heavy manure application (this is not necessarily a problem, however). Sick root nodules are just one more symptom that you may be able to use to trace down and solve a problem.

Source: How to Grow Super Soybeans