AG NEWS
AG NEWS

Considering Cover Crops

  • Oct 25, 2016
Farmer and Retailer
Cover crops are increasing in popularity due to benefits for sustainability. If you’re considering them, here is some information about the advantages and challenges associated with cover crops.
 
Potential advantages of cover crops
Properly established cover crops can reduce soil erosion and nitrogen sequestration, build soil tilth, increase water- and nutrient-holding capacity, and foster diverse soil fauna and microbes. These benefits could provide long- and short-term economic advantages through increased yields; better weed control; and nitrogen conservation, sequestration or addition. 
 
Potential disadvantages of cover crops
Cover crops can be challenging to establish without affecting the primary crop and may even be cost-prohibitive in the short term. If they are seeded in a broadcast fashion in a standing crop, cover crops will only establish with adequate moisture and light under the canopy.
 
If seeded after harvest of the primary crop, the window for cover crops to germinate and establish may be short. Once established, cover crop residues can make it difficult to attain quality primary crop stands, especially corn. Finally, depending on the cover crop species and operational costs, you could spend a sizable amount on seed. Check with your agronomist to see if Natural Resources Conservation Service (NRCS) cost-share options are available in your area.
 
Benefits for sustainability
Cover crops shield soil from the impact of rain and wind, which reduces erosion. Second, cover crop root systems provide many benefits. They penetrate compacted soils, creating root channels that make soil more porous, resulting in improved infiltration of air, water and subsequent crop root systems. Live root systems also foster soil microbial growth and produce organic compounds that bind soil particles together to create better soil structure, which also helps reduce erosion.
 
Some cover crops can also keep nitrogen out of groundwater. For example, cereal grains such as rye, oat, wheat, triticale, etc. scavenge for nitrates in the profile and convert them to stable organic forms.  Legume cover crop species fix nitrogen from the air and provide an organic nitrogen source for the upcoming cash crop.
 
The increased biomass created by cover crops converts to organic matter over time, providing many benefits, including increased water- and nutrient-holding capacity.
 
Cultivation practices
Although farmers employing no-till or strip-till methods may have more experience with and tools for dealing with crop residues, cover crops are not just meant to be incorporated into minimum-till systems. Keeping live plants in the soil as long as possible during the growing season provides advantages even for conventional tillage systems.
 
The time you put into planning and preparing will determine your ultimate success with cover crops. And, though there are many short-term benefits, remember that the economic advantages may become evident further down the road. Be clear about your goals and expectations before starting down the path.