Pennycress as a Cash Cover-Crop: Improving the Sustainability of Sweet Corn Production Systems

Sarah A Moore,Roger L Becker,Carl J Rosen,M Scott Wells,Russ W Gesch,Melissa L Wilson

doi:10.3390/agronomy10050614

Sarah A Moore, Roger L Becker + Show 4 more

Open Access

https://doi.org/10.3390/agronomy10050614

Copy DOI

Abstract

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.

Highlights

Sweet corn (Zea mays convar. saccharata var. rugosa) is grown in many regions across the world, including the Americas, Asia, Europe, Middle East, Africa and Australia [1,2,3], with the highest production in the United States
Sweet corn requires approximately 200 kg N ha−1 to achieve high-quality ears [6,9]. While this fertilizer rate is comparable to recommendations for field corn (Zea mays L.), sweet corn is seeded at lower population densities and is harvested as a fresh vegetable rather than at grain maturity, meaning that 34.3% to 50% of the N applied as fertilizer is not utilized by the crop, and is susceptible to transport off-site [5,10,11]
The rate of nitrogen (N) applied to sweet corn did not affect the following pennycress seed yield, total aboveground biomass or biomass N content, indicating that maximum pennycress yields may be attained under relatively low fertilizer regimes in most years

Summary

Introduction

Sweet corn (Zea mays convar. saccharata var. rugosa) is grown in many regions across the world, including the Americas, Asia, Europe, Middle East, Africa and Australia [1,2,3], with the highest production in the United States. Sweet corn has a proportionally larger potential to contribute to nitrogen (N) pollution, with three times the residual inorganic soil N of grain maize and soybean. This occurs as a result of the high fertilizer requirements to optimize ear or cut-kernel yield, which subsequently results in high N residue left on the field after harvest [6,7,8]. While this fertilizer rate is comparable to recommendations for field corn (Zea mays L.), sweet corn is seeded at lower population densities and is harvested as a fresh vegetable rather than at grain maturity, meaning that 34.3% to 50% of the N applied as fertilizer is not utilized by the crop, and is susceptible to transport off-site [5,10,11]

Objectives

Methods

Results

Discussion

Conclusion