This is not a comprehensive list of all research conducted at this time.
Pennycress as a Cash Cover-Crop: Improving the Sustainability of Sweet Corn Production Systems.
Commercial sweet corn (Zea mays convar. saccharata var. rugosa) production has a proportionally high potential for nutrient loss to waterways, due to its high nitrogen (N) requirements and low N use efficiency. Cover crops planted after sweet corn can help ameliorate N lost from the field, but farmers are reluctant to utilize cover crops due to a lack of economic incentive. Pennycress (Thlaspi arvense L.) is a winter annual that can provide both economic and environmental benefits. Five N-rates (0, 65, 135, 135 split and 200) were applied pre-plant to sweet corn. After the sweet corn harvest, pennycress was planted into the sweet corn residue with two seeding methods and harvested for seed the following spring. Residual inorganic soil N (Nmin), pennycress biomass, biomass N and yield were measured. The nitrogen rate and seeding method had no effect on pennycress yield, biomass, or biomass N content. The nitrogen rate positively affected Nmin at pennycress seeding, wherein 200N plots had 38–80% higher Nmin than 0N plots, but had no effect on Nmin at pennycress harvest. Control treatments without pennycress had an average of 27–42% greater Nmin. In conclusion, pennycress can act as an effective N catch crop, and produce an adequate seed yield after sweet corn without the need for supplemental fertilization.
Moore, S. A., Wells, M. S., Gesch, R. W., Becker, R. L., Rosen, C. J., & Wilson, M. L. (2020). Pennycress as a Cash Cover-Crop: Improving the Sustainability of Sweet Corn Production Systems. Agronomy, 10(5), 614. https://doi.org/10.3390/agronomy10050614
Tillage intensity influences nitrogen cycling in organic kura clover living mulch.
Perennial cover crops, also known as living mulches, have the capacity to improve soil quality, yet their effects on nitrogen (N) cycling and provisioning in organic systems are not well understood. We evaluated soil N contributions of kura clover (Trifolium ambiguum) between and within crop rows for four zone tillage approaches of varying intensity for corn (Zea mays). In 2015 and 2016, an established kura clover field was subjected to tillage treatments including no-till, traditional shank till, also known as strip-till (ST), novel, PTO-driven rotary zone till (ZT), and a combination of ST and ZT (DT; double till) in Rosemount, MN, followed by corn. An earlier planting date in 2015 (May 5, 2015 vs. May 18, 2016) contributed to a substantially lower rate of kura clover biomass at corn planting in 2015 (518 kg ha−1) compared to 2016 (3035 kg ha−1). The substantial difference in kura clover biomass contributions at tillage and planting between years appeared to govern N cycling indicators. For instance, soil inorganic N differed by tillage treatments only in 2016. After tillage, within row soil inorganic N was 68% and 106% greater than between rows for ST and DT treatments, respectively. At harvest, DT within row soil inorganic N was approximately double that of ST. We conclude that the N benefit from a legume living mulch depends on both the intensity of tillage and the amount of biomass present, and thus there may be advantages to delayed planting, particularly when used for organic production.
Peyton, G., Grossman, J., Baker, J., & Sooksa-nguan Thanwalee. (2020). Tillage intensity influences nitrogen cycling in organic kura clover living mulch. Nutrient Cycling in Agroecosystems, 116(1), 71-82. https://doi.org/10.1007/s10705-019-10025-0