Actual and potential yield for rainfed and irrigated wheat in China

Abstract

The parametric water use and crop yield model (YIELD) was applied to China and Korea in order to examine the responses of potential and actual winter wheat yield parameters necessary for optimal crop production in that region. A network of 241 stations provided the seasonal climatic input, consisting of data averaged over approximately a 20 year period. Among the results, highest annual yields under full irrigation occurred in the Yangtze River area, Yunnan—Szechwan—eastern Tibet, Korea and the northeast, and the upper Huang Ho River. Lowest yields were calculated for the northwestern interior. High annual yields exceeded 5–6,000 kg ha −1. Under rainfed-only conditions, the management efficiency of wheat production was higher in many regions than cases with full irrigation. In order to achieve optimum crop yields, about 400 mm of irrigation water was needed in the northwest, contrasted with none required in the south and east of China. A sensitivity analysis was applied to determine the degree of error introduced by faulty, uncertain, or missing environmental input data for the stations utilized in this study.