The Drought Monitor showed marked improvement for all of central and even most of western Kansas. Northwest Kansas, except for the extreme corner which is abnormally dry, is out of dry conditions. The area of dry and moderate drought retreated to the west of Ford County and there is only a small area of severe drought along the Colorado border. The 6 to ten day outlook (March 4 to 8) has below normal precipitation and normal to above normal temperatures which bodes well for the wheat crops emergence from dormancy. Looking out 8 to fourteen days (March 6 to 12) indicates below normal precipitation and above normal temperatures. This should allow for the application of nitrogen and herbicides for the wheat crop as many producers are behind with the past few weeks weather. With the moisture present as of now, this is again good for the 2020 wheat crop and for preparing to plant the 2020 corn crop. The 30 day outlook is for below normal temperatures and a coin flip for precipitation with the ninety day outlook basically near normal for both. Today, let’s briefly discuss an extremely hot topic in production agriculture – cover crops.
First, for context, let’s define cover crop and green manure. A cover crop is defined as “plants that are planted to cover the soil rather than for the purpose of being harvested. They manage soil erosion, soil fertility, soil quality, water, weeds, pests, diseases, biodiversity and wildlife in an agroecosystem.” A green manure is defined as “A crop grown and plowed under for its beneficial effects to the soil and subsequent crops, though during its growth it may be grazed. These crops are usually annuals, either grasses or legumes. They add nitrogen to the soil, increase the general fertility level, reduce erosion, improve the physical condition of the soil, and reduce nutrient loss from leaching. They are usually planted in the fall and turned under in the spring before the summer crop is sown and while green.”
Cover crops and green manures are hardly a new topic, starting to receive renewed interest back in the early 1980s. This coincided with interest in “organic” or “sustainable” production of crops and the desire to decrease/eliminate the use of synthetic pesticides and synthetic/inorganic fertilizers. Keep in mind that a green manure can be a cover crop but the major difference is that a green manure is worked into the soil while actively growing so using a green manure doesn’t fit into a no-till system. The cover crop is terminated in time for the planting of the succeeding crop, normally with enough time to prepare for the harvested crop. While normally planted in the fall, there are also many planting summer cover crops. And while initially geared toward “organic” farming operations, they are used in more and more convention operations.
Legumes (clover, vetches, peas, etc.) are promoted as they fix nitrogen which can be broken down and provide “free” nitrogen. Non-legume broadleaves such as brassica species and annual grasses are also often used. While they don’t provide as much “free” nitrogen, they do provide organic matter and a carbon/nutrient source for a healthy microbial population. Next week – the advantages and disadvantages of cover crops.
Dr. Victor L. Martin is the agriculture instructor/coordinator for Barton Community College. He can be reached at 620-792-9207, ext. 207.