High Yielding Performance of Soybean in Northern Xinjiang, China
Akihiro Isoda, Masanobu Mori, Shunsuke Matsumoto, Zhiyuan Li* and Peiwu Wang*
(Faculty of Horticulture, Chiba University, Matsudo 648 Chiba 271, Japan; *Shihezi Agricultural and Environmental Institute for Arid Area in Central Asia, Shihezi, Xinjiang, China)
The experimental site (Shihezi, Xinjiang, China) is located in an arid area of central Asia with abundant solar radiation, i.e., the daily sunshine hours from Apr. to Sept. are almost 10. The yield potential in this area appears to be high if sufficient water is supplied. The yields of five soybean (Glycine max (L.) Merr.) cultivars, including three indeterminate Chinese cultivars (Shidadou 1, Xindadou 1 and Suinong 11) and two determinate Japanese cultivars (Toyomusume and Toyokomachi) were evaluated over three years. These cultivars were grown under drip irrigation, a high planting density (22.2 plants m-2) and heavy applications of farmyard manure (15 t ha-1). Each cultivar showed a large leaf area index (LAI). In particular, the maximum LAIs of Shidadou 1 and Toyokomachi were greater than seven over the three years. The three Chinese cultivars had a low leaf area in the upper layers with a high plant height. The two Japanese cultivars had larger LAIs in the middle or upper layers with a short plant height. Toyokomachi and Shidadou 1 had the highest seed yield, followed by Toyomusume. In particular, Toyokomachi averaged 8.67 t ha-1 over the three years. These high-yielding cultivars had more than 60 pods per plant (1350 m-2). Possible reasons for the high yields in this experiment were a large amount of intercepted radiation as the product of large LAI and abundant solar radiation, no marked water stress due to frequent and sufficient irrigation by the drip irrigation, and bearing a lot of pods as a sink.
Keywords: Abundant solar radiation, Drip irrigation, Glycine max (L.) Merr., Leaf area index, Pod number, Yield, Xinjiang.