There is no one-size-fits-all approach when it comes to utilizing cover crops. Cover crops can be a boon for soil health, but how much the covers can improve the soil depends on how much biomass that cover crop species produces. In turn, larger amounts of biomass means more sequestration of carbon in the soil, better control of water erosion and nitrate leaching and improving other soil properties.
Using cover crops to build biomass is not a new concept. In fact, there are multiple combinations of cash crops and covers that can be rotated to accomplish this goal. In addition, some forms of biomass — such as cover crop species used for hay and/or silage for livestock — can be another income stream for growers, while still taking advantage of the soil health benefits that cover crops have to offer.
Using nitrogen-fixing cover crop species can also mean less use of synthetic fertilizer on fields, which leads to less nitrate leaching.
Of course, growers have a plethora of considerations when choosing the best cover crop species for their operations, including soil type, climate, timing of cover crop seeding, and more.
A team from the University of Nebraska is starting a 4-year research project to look at how altering planting and termination dates of cover crops can increase biomass production. Leading the team is Humberto Blanco, a professor of soil management and soil physics. Funding for the project is provided by a grant from the USDA National Institute of Food & Agriculture.
The study will evaluate cover crops planted pre- or post-harvest and terminated a month before or at main crop planting. Data will evaluate the physical, chemical, fertility and biological properties of the soil, in addition to the quality of water stored in the soil, amount of carbon stored in the soil and the crop yields from fields where covers were planted. Data will also look at the economic analysis of cover crops, including production inputs, outputs and value-added benefits from the covers.
The project will focus on sloping and sandy soils, which are more prone to leaching nitrates.
It will be very interesting to see what results come from the University of Nebraska research.