Cover crops are planted primarily to protect soil structure, and improve soil fertility and quality. It is established during the off season of the main crops to cover the soil surface to minimize land degradation by wind and water erosion and nutrient losses through leaching and runoff processes. Among the benefits of cover cropping include: improvement of soil physical and chemical properties, organic matter content, and microbial activity and diversity, all results in overall improvement of soil’s health and productivity.
In Louisiana, the adoption of cover cropping has been increasing due to its known positive impacts on soil quality and nutrient cycling, especially nitrogen. A recent work done on cover cropping in corn showed an increased in calcium, copper, magnesium and potassium content of soil for plots with cover crops grown during the off season of the main crop. However, the amount of documentation on the value of cover crops (single or mixed seeds) in terms of absolute nutrient contribution and its subsequent impact on crop fertilizer requirement is still lacking. In addition, cultural management practices that may play a role in biomass production of cover crops and its overall nutrient contribution are not well understood.
There are a lot of factors affecting the timely implementation of any field operation (e.g. planting, harvesting etc.). In addition, just like any plants, cover crops need nutrients; deficiency of any nutrients may impact their growth and biomass production. Typically, starter fertilizer is applied to facilitate the nutrient acquisition of newly planted crops at a period (at planting or crop early growth stage) where their root systems are still small and cool temperature limits the release of nutrients from organic matter decomposition. For these reasons, optimal planting date and fertilization can potentially improve biomass production of cover crops. The differences in biomass production may affect the level of soil surface protection, nutrient removal (of cover crops) and its nutrient contribution to the subsequent main crops, optimum fertilizer requirement of the main crop, and soil health.