Performance of soybean cultivated following intercropped corn under varying nitrogen levels

Abstract

The intercropping of second-crop corn with ruzigrass or showy rattlebox associated with an increase in the nitrogen (N) rate can improve the performance of soybean in succession. This study aimed to evaluate the soybean performance in succession to second-crop corn cultivated under N application rates, with or without intercropping with ruzigrass (Urochloa ruziziensis) or showy rattlebox (Crotalaria spectabilis). The experimental design was a complete randomized block design with a split-plot scheme with four replicates. The plots were composed of the cultivation of either sole corn (AG 9010 PRO) or corn intercropped with ruzigrass or showy rattlebox, and the subplots consisted of different N topdressing rates (0, 60, 120, 180, and 240 kg ha-1). Soybean (BRS 1003 IPRO) was grown in succession to corn under a no-tillage system (NTS). The evaluated variables were growth and yield. The increase in N rate in second-crop corn, with or without intercropping with ruzigrass or showy rattlebox, increased the growth and yield of soybean in succession under NTS. Second-crop corn intercropped with ruzigrass provided a greater amount of straw under NTS than sole corn or intercropped with showy rattlebox. However, intercropped systems did not influence the growth and yield of soybean grown in succession. Therefore, the corn intercropped with ruzigrass promotes the sustainability of NTS and the N fertilization in second-crop corn, which subsequently improves soybeans performance