The Use of Faba Bean Cover Crop to Enhance the Sustainability and Resiliency of No-Till Corn Silage Production and Soil Characteristics

Abstract

Sustainable corn production requires a dramatic shift toward natural soil fertility rather than relying solely on synthetic fertilizers. Cover crops play an important role in improving the productivity of subsequent row crops through improving soil properties. The main goal of this study was to investigate if increasing cover crop biomass through applying a higher density can enhance soil characteristics in the short term and contribute more nitrogen to succeeding corn silage. In a two-year field study (2018–2019), the influence of faba bean (Vicia faba L.) as a cover crop on soil characteristics and corn silage (Zea mays L.) production was evaluated. Treatments consisted of five levels of faba bean density (0, 25, 35, 40, and 80 plants m−2) and four application rates of urea-based nitrogen fertilizer (0, 100, 200, and 300 kg ha−1) in a no-till system. The measured soil characteristics were not significantly affected through increasing cover crop density to 80 plants m−2. The faba bean roots comprised 33% of total biomass in densities ranging from 25–40 plants m−2. The highest total N yield (root + shoot) was 133 kg N ha−1, obtained from 40 faba bean plants m−2. The faba bean root decomposed faster than the shoot, and the addition of N to the corn accelerated 50% N release from the roots but had no significant effect on shoot decomposition. Corn planted after 40 plants m−2 faba bean yielded 28% more than the corn with no faba bean. Corn yielded less in no-cover-crop fields even when it received the highest synthetic N rate (300 kg N ha−1), indicating the value of including faba bean in rotation with corn.

Keywords

• faba bean cover crop
• biological nitrogen fixation
• faba bean residue decomposition
• nitrogen yield of roots and shoot
• soil characteristics
• sustainable corn production