Growing perennial cover crops under annual maize crops can bring substantial benefits to the soil and environment without compromising maize yields, according to Iowa State University research. The study shows that soil and water quality, and possibly even farm profits could all stand to benefit from this technique.
The researchers used standard agronomic practices to manage a cover crop of perennial Kentucky bluegrass – the most suitable crop found – between rows of maize which was established annually using strip tillage. The system they used kept soil, carbon and nutrients in the fields, rather than it being lost to erosion, runoff and the atmosphere, and still allowed 200 bushels of corn to be yielded per acre (12.6 tonnes/hectare). This compares very favourably with these 10-year average yields for the state of IOWA.
One of the drivers for the research was the potential future demand for stover – corn residues – for use in producing biofuels. Currently this usually remains on the ground after the crop is harvested and helps reduce soil erosion and replenishes nutrients and organic matter. But the prospect of this being removed led many to fear that soil erosion and nutrient loss would increase as biofuel technologies developed.
Read the full report here.