Soybean yield response to gypsum soil amendment, cover crop, and rotation

Growing demand for soybean [Glycine max (L.) Merr.] creates pressure to expand soybean production onto marginal lands and grow soybean continuously. Experiments comparing continuous soybean with soybean–corn (Zea mays L.) rotation, cereal rye [Secale cereale (L.)] cover crop with no cover crop, and flue‐gas desulfurization (FGD) gypsum surface‐applied at 0, 1.1, and 2.2 Mg ha−1 were conducted at Shorter, AL, Farmland, IN, Hoytville, OH, and Piketon, OH, for 5 yr. The objective was to evaluate soybean yield response to these practices across a range of soil types and climatic conditions. Response to continuous soybean and cover crop varied by site (soil drainage class) with no interaction effects. Continuous soybean reduced yield only on well‐ and moderately well‐drained soil types. Cover crop reduced yield on the very poorly drained soil type and increased yield on the well‐drained soil type. Crop production practices that promote soil health and sustainability may not provide yield improvement.