Maize-soybean intercrop silage yield and quality with different nitrogen levels and plant population

This study hypothesizes that maize-soybean intercrop with lower maize plant population and nitrogen levels can allow better soybean development and yield, which may offset lower maize biomass and silage crude protein yield. Experiment was carried out in a randomized complete block design arranged in a 2 x 5 factorial scheme, with three replications. Treatments consisted of two different maize-soybean plant stand (40,000 and 60,000 plants ha-1) and five nitrogen fertilization levels (0, 50, 100, 150, and 200 kg ha-1). As a result, soybean biomass yield increased at the lower maize plant stand, although, maize and total (maize + soybean) biomass yield were higher at the greater maize plant stand. Thus, individual maize plants and total dry matter yield increased as nitrogen levels were increased. However, there was no effect of the studied factors on the silage crude protein yield per area, indicating a great potential of soybean to offset biomass yield reduction trough silage quality improvement. Moreover, since there was no difference on total silage crude protein yield per hectare, it is suggested that the adoption of maize-soybean intercrop with lower maize plant stand (40 thousand maize plants ha-1) and with lower nitrogen values is a more environmentally friendly approach to increase farmland sustainability while decreasing environmental and productivity costs. Intermediate levels may be evaluated in future studies