YIELD FORMATION CAPACITY, SOIL WATER CONSUMPTION PROPERTY, AND PLANT WATER USE EFFICIENCY OF WHEAT UNDER WATER-SAVING CONDITIONS IN NORTH CHINA PLAIN

The drastically reduced underground water and shortage of the water resource have caused limitation for the winter wheat (T. aestivum) production in North China Plain. In this study, using a drought-tolerant wheat cultivar Shimai 18 as material, we investigated the yield formation capacity, soil water consumption property, and the plant water use efficiency (WUE) of wheat under various irrigation treatments. Our results indicated that the yield capacities of wheat varied largely across irrigation treatments in three growth seasons with contrasting precipitation patterns. The wheat yields showed constant in growth season with more rainfall and lowered to some extent in seasons with regular or less rainfall under I1 (water-saving condition with one time of irrigation) compared with I3 (regular irrigation with three times of irrigation). Along with increase of the irrigation times, plant WUE lowered drastically in all of three growth seasons examined, together with significantly increased evapotranspiration (ET) amount and relative constant of soil water deposits. These results suggested that the water-saving management is feasible in the winter wheat production in North China Plain. Additionally, the plant leaf area index (LAI), dry matter accumulation, and biomass partitioning rate of vegetative tissues during late growth stage (from flowering to maturity) were consistent with the yield formation capacities of the wheat cultivar. Our investigation indicates that the water-saving management using drought tolerant cultivars is effective in production of winter wheat in North China Plain, which can drastically improve the plant WUE and maintain the sustainable wheat productivity under reduced irrigation conditions.