Cover Crops Increase the Yield and Profitability of Soybean–Wheat Cropping Systems in Southern Brazil
摘要
The soybean–wheat cropping system holds great economic importance in Brazil, particularly in the southern region. Between soybean harvest and wheat sowing, there is a 2-month period (March–April) during which agricultural fields are typically kept fallow. An alternative is to plant cover crops during this period. The study aimed to investigate the effects of distinct cover crop species grown sole or as intercrops between soybean harvest and wheat sowing on the yields and profitability of a soybean–wheat production system in southern Brazil. We conducted a 3-year experiment in an Oxisol with a highly clayey texture. The seven cover crop treatments, applied between March and April, consisted of slender leaf rattlebox, buckwheat, oilseed radish, maize at a high planting density, pearl millet, maize + oilseed radish, and pearl millet + oilseed radish. Pearl millet, pearl millet + oilseed radish, and maize had the highest mean biomass productivities during the 3-year experimental period (5234, 4732, and 4573 kg ha− 1, respectively). Wheat grown in succession to slender leaf rattlebox, fallow, oilseed radish, buckwheat, and maize + oilseed radish showed the highest yields (3249, 3231, 3044, 2983, and 2982 kg ha− 1, respectively). Maize + oilseed radish, oilseed radish, slender leaf rattlebox, maize, pearl millet, and pearl millet + oilseed radish produced the highest soybean yields (4050, 3996, 3915, 3904, 3884, and 3849 kg ha− 1, respectively). The profits obtained from soybean–wheat production were higher with the cultivation of maize + oilseed radish, oilseed radish, and slender leaf rattlebox (US$700, 687, and 662 ha− 1) than with fallow (US$642 ha− 1).