Cover crops and landscape positions mediate corn–soybean production

Abstract

AbstractEcosystem services and cash crop benefits provided by cover crops (CCs) can be affected by temporal and spatial variability of CC performances as influenced by topographic position of the field. A watershed‐scale study was initiated in 2015 to assess the influence of crop rotations [cereal rye (Secale cereale L.)–soybean [Glycine max (L.) Merr.]–hairy vetch (Vicia villosa Roth.)–corn (Zea mays L.) (CC) and winter‐fallow soybean–winter‐fallow corn (NoCC)] and topography (i.e., shoulder, backslope, and footslope) on corn and soybean productivity in southern Illinois. Cereal rye increased soybean yield by 0.29 Mg ha‐1 at the shoulder position, but it reduced yield by 0.44 Mg ha‐1 at the footslope position when compared with the NoCC treatments. At the footslope position, every 1 Mg ha‐1 increase in cereal rye biomass increased soybean yield by 0.87 Mg ha‐1. Soybean yield was negatively related to the cereal rye biomass at the shoulder and backslope positions. Within the CC rotation, corn yield was greater at the shoulder and backslope positions than at the footslope. Hairy vetch biomass affected corn yield positively within each landscape position. Cover cropping did not improve soybean and corn yield at the footslope position. Site‐specific CC management is critical if the landscape has significant variability in soil characteristics.