Ridge-furrow planting promotes wheat grain yield and water productivity in the irrigated sub-humid region of China

Determining methods for increasing irrigation water productivity is important for sustaining high wheat grain yields in the irrigated region of the Loess Plateau in China. Plastic-covered ridge and furrow planting has been widely applied in dryland farming, as it markedly increases precipitation productivity and crop yields. However, whether this planting system can significantly increase irrigation water productivity and whether it can reduce the irrigation volume for high-yielding wheat production in irrigated regions of the Loess Plateau are unclear. In the present study, plastic-covered ridge and furrow planting and traditional flatbed planting were performed at four irrigation levels. The objective was to investigate whether applying plastic-covered ridge and furrow planting to an irrigated farmland system could reduce the irrigation water requirements and increase water productivity for high-yielding wheat production. The results suggested that plastic-covered ridge and furrow planting significantly increased soil moisture content and increased both grain yield and water productivity of wheat. At the 0, 400, 1200, and 2000 m(3) ha(-1) irrigation levels, compared with that resulting from traditional flatbed planting, the grain yield resulting from plastic-covered ridge and furrow planting was 51.7 %, 64.8 %, 25.5 %, and 5.84 % greater, respectively. At the high-grain-yield level (6-7 t ha(-1)), the plastic-covered ridge and furrow planting system at 1200 m(3) ha(-1) irrigation conserved 40 % of irrigation water during wheat production. And it coordinated the relationships among grain yield, quality, water protuctivity and for wheat production. These findings show that the plastic-covered ridge and furrow planting system with 1200 m(3) ha(-1) irrigation is suitable for sustainable high-yielding wheat production in the irrigated regions of the Loess Plateau of China.