Improving Soil Quality with Covercrops
by Ryan Graycheck — Written for June 13th CSA Newsletter
Cover cropping is one of our three C’s to improve the soil quality of the farm. It is also a great way to suppress weeds, prevent soil erosion, build productive soils, attract beneficial insects, and help to control pests and disease.
Cover cropping is a great way to reduce weeds in your fields. We are using buckwhat this summer in an effort to control summer annual and perrenial weeds. Since buckwheat germinates quickly it is an effective way to reduce germination success of weeds and shading out and out competing the weeds that have germinated.
The use of covercropping is a great way to prevent soil erosion. By reducing the amount of water that drains off of the field we can reduce the risks to waterways and ecosystems downstream as well as keeping the soil and nutrients where we want them.
Cover cropping is especially helpful in increasing soil fertility. Cover crops are planted to manage a range of soil macronutrients and micronutrients. The impact of cover crops on nitrogen management is most notable because nitrogen is often one of the most limiting nutrients in vegetable production. Often plants are grown for specific periods of time and then plowed under before reaching full maturity and at its peak nitrogen content and in order to add sufficient organic matter to the soil. Often the crops used are leguminous meaning they are part of the Fabacea (pea) family. All of the species in this family produce pods and are high in nitrogen which can typically provide the amount of nitrogen used for crop production. Leguminous crops also form a symbiotic relationship with the rhizobial bacteria that reside in legume root nodules. These bacteria help in the process of biological nitrogen fixation.
By growing cover crops that attract beneficial insects to the farm we hope to reduce the amount of pests that attack our plants and the need to spray. Cover crops can also break disease cycles and reduce populations of bacterial and fungal diseases and parasitic nematodes in the soil.
Buckwheat has a fibrous root system and the seed can germinate within days of planting. This makes it a great choice for suppressing summer annual weeds and perrenial weeds while reducing next year’s weed seed bank. The buckwheat will also help prevent soil erosion while attracting pollinators and other beneficial insects to help our plants thrive.
Buckwheat is a succulent and does not require much water making it a great choice for our hot and dry summers. Becuase it is a succulent it tends to decompose rapidly which does not add a whole lot of organic matter to the soil but will help with the soil tilth making it easier to plant your following crop. It is however efficient at taking up phosphorus from the soil and storing it in its tissues. There is research indicating that incorporating buckwheat residues in your soil can increase phosphorus availability to the subsequent crop.