Planting pattern and pre-sowing soil moisture effect on yield of soybean

This study aimed to investigate the effects of planting patterns and pre-sowing soil moisture on the yield of summer soybean [Glycine max (L.) Merr.] in northern China from 2009 to 2010. The experiment comprised three planting patterns, namely, 30 cm uniform row spacing pattern (U), “20 + 40” wide-narrow row planting pattern (WN), and “20 + 40” furrow planting pattern (F). Three pre-sowing soil moisture treatments were performed at 90, 135, and 180 mm and involved irrigation during the winter wheat growth season. The leaf area index and chlorophyll content index of F were higher than those of U and WN under the same pre-sowing soil moisture treatment (P < 0.05). The accumulation of dry matter and the grain yield of F were significantly higher than those of U and WN (P < 0.05) irrespective of water content. The increase in grain yields of summer soybean was significant in 2009 (P < 0.05) but not in 2010 (P > 0.05) for 135 and 180 mm pre-sowing soil moisture under F. In conclusion, F and 180 mm pre-sowing soil moisture treatments were good agronomic measures to increase the yield of summer soybean in northern China.