Effect of Water Table Depth on Growth and Yield of Soybean Yudou 16

Abstract

In 2005–2006, a multilysimeter study was conducted to determine the effect of various water table depths (WTDs) (0.2, 0.4, 0.6, 0.8, 1.0, 2.0, 3.0, 4.0, and 5.0 m) on the growth of soybean variety Yudou 16 in the transitional zone of northern semitropical and warm temperate climatic conditions of the Huaibei Plain, Anhui Province, China. In the experiment, precipitation was accounted for and WTD was controlled. The yield of Yudou 16 soybeans was greatest with a WTD of 2 m; yield decreased when the WTD was deeper or shallower than 2 m. From 0.2 through 2.0 m soybean yield increased rapidly with increasing WTD because shallow WTDs produced an oversupply of water in the root zone. From 2 through 5 m yield decreased slowly with increasing WTD under the experimental conditions. This was apparently because deeper WTDs could not compensate (through phreatic evaporation) for rainless periods of moisture stress during the growing season. When the constant WTD changes from 0.8 to 4.0 m, the yield is equal to or greater than the local field yield, with a variable WTD of 0.3 to 3.4 m. This suggested that field production could be improved if WTD were controlled to changing within 0.8 to 4 m. These results should help to guide more precise planning and efficient management of soybean cultivation in this region.