Crop-damaging nematodes and soil-borne pests can be controlled by the proper use of specific cover crops.
The natural biochemicals exuded from certain varieties suppress the growth of nematodes by inducing the eggs to hatch prematurely without a suitable food source. This causes them to starve and interrupts the reproductive cycle.
Biofumigation, which occurs when certain varieties release high levels of glucosinates into the soil, can also mitigate soil-borne pests.
Water infiltration is improved with the use of cover crops. When a field lays fallow for a period of time, the surface tends to seal, and water will run off. Cover crops protect the soil's surface, reduce sealing, and can improve drainage of wet soils. Organic matter added by cover crops can hold moisture in the soil profile for use by the following crop.
A dense stand of the right cover crops can suppress weeds by soil shading. Some species also have allelopathic qualities, which naturally inhibit weed growth. Allelopathy refers to the beneficial (or harmful) effects of one plant on another plant, both crop and weed species, through the release of chemicals from plant parts (by leaching).
Beneficial insects such as lady bugs, ground beetles, and pollinators are natural predators of harmful insects. Planting certain cover crops will attract these helpful insects, thereby lessening the need for costly insecticides.
Cover crops can feed not only organisms below ground but also those above ground - your livestock. Double up on the benefits by planting crops like annual ryegrass, balansa clover, nematode control radish, daikon radish, crimson clover, or medium red clover.
The prevention of land degradation by wind and water erosion is an important function of cover crops. Holding soil in place in order to capture and retain moisture from rainfall is one of the first steps in improving its health and productivity.
Legumes can add substantial amounts of available nitrogen to the soil. Non-legumes can be used to take up excess nitrogen from previous crops, as well as phosphorus and potassium, making it available to the following crop. Beneficial organisms in the soil, such as earthworms and microbes, thrive when fresh plant material is decomposing. Organic matter levels can greatly improve with the addition of cover crops.
Often, cover crops are planted toward the end of the growing season. For this reason, cover crop species that establish quickly and accumulate biomass in a short period of time are essential to achieve the goals you have for your cover crop.
Compaction occurs when soil volume is reduced. Compacted soil is dense and has low porosity. Cover Crops with deep, fibrous, or tap-root systems help alleviate compaction by creating root channels and breaking up dense soil and hard pan.
Nutrients left behind by cash crops are at risk of being washed away or purged through the soil strata below the reach of subsequent crops. Some cover crops are ideally suited to sequester these nutrients, preventing them from being lost. These valuable nutrients are released back into the soil for the next crop.