Effect of soybean on yield and nitrogen response of subsequent sorghum crops in Eastern Nebraska

• Published in: Field crops research 1982, Vol.5 (3), p.233-239
• Main Author: Clegg, M.D.
• Format: Article
• Language: English
• Subjects: Glycine max; Sorghum bicolor
• ISSN: 0378-4290; 1872-6852
• DOI: 10.1016/0378-4290(82)90026-0

Sorghum [ Sorghum bicolor (L.) Moench] and soybeans [ Glycine max (L.) Merr.] are two crops which will grow in the same environments and therefore are often grown in rotation. This study was to determine the benefit from the legume on the subsequent sorghum crop. The cropping systems were established at Mead, Nebraska, on soils that are generally Typic Argiudolls. The crop systems included continuous sorghum, continuous soybeans and sorghum and soybeans in rotation. Four nitrogen levels (0, 57, 114 and 170 kg/ha N) were applied to sorghum in each system. A randomized complete block design with four replication was used. Average grain yield of sorghum grown continuously with 0 N applied was 4616 kg/ha as compared to 6551 kg/ha when grown after soybeans in rotation. The estimated available N for sorghum after soybeans was 76± 19 kg/ha. Regression analysis showed maximum grain yields of continuously grown sorghum would be expected to occur with application of 150 kg/ha N and with application of 95 kg/ha when grown in rotation. On this soil a large portion of sorghum nitrogen requirement can be met by growing it in rotation with soybeans. Perhaps in subsistance agriculture a legume—cereal system could supply nitrogen which otherwise would not be available.