土壤深松和补灌对小麦干物质生产及水分利用率的影响

研究一次深松耕作后土壤水分对冬小麦籽粒产量和水分利用率的影响,为小麦节水高产栽培提供理论依据.于2008-2009和2009-2010两个小麦生长季,选用高产小麦品种济麦22,采取测墒补灌的方法,研究了深松+旋耕和旋耕2种耕作方式下土壤水分对小麦0-200 cm土层土壤含水量、干物质积累与分配、籽粒产量及水分利用率的影响.结果表明,(1)深松+旋耕40-180 cm土层土壤含水量低于旋耕处理；旗叶光合速率和水分利用率,开花后干物质积累量及其对籽粒的贡献率显著高于旋耕处理.(2)W3(补灌至0-140 cm土层土壤相对含水量播种期为85％,越冬期80％,拔节和开花期75％)成熟期0-200cm土层土壤含水量与W1(播种期80％,越冬期80％,拔节和开花期75％)和W2处理(播种期80％,越冬期85％,拔节和开花期75％)无显著差异；W3和W''3(播种期85％,越冬期85％,拔节和开花期75％)60-140 cm土层土壤含水量分别低于W4(播种期85％,越冬期85％,拔节和开花期75％)和W''4(播种期90％,越冬期85％,拔节和开花期75％)处理；W3和W''3灌浆中后期旗叶光合速率较高,开花后干物质积累量及其对籽粒的贡献率显著高于其他处理,获得高的籽粒产量和水分利用率.综合考虑籽粒产量、水分利用率和灌溉效益,在深松+旋耕条件下,两年度分别以W3和W''3为节水高产的最佳处理.

Effects of subsoiling and supplemental irrigation on dry matter production and water use efficiency in wheat

Simultaneous increase of grain yield and water use efficiency is an imperative solution and a hot focus on crop production and research, especially in northern plain of China where winter wheat (Triticum aestivum) is the largest water-consumed crop. The objective of this study was to optimize irrigation scheduling for both high grain yield and water use efficiency of wheat with different tillage practices. Unlike earlier studies in which fixed irrigation amounts were given, a strategy of water-controlled irrigation based on measuring soil water content was adopted to study changes in soil water content in 0-200cm at maturity, dry matter accumulation and distribution, grain yield, and water use efficiency. In a continuous experiment across two growing seasons from 2008 to 2010, we planted wheat cultivar Jimai 22 with two tillage treatments including rotary tillage after subsoiling (RS) and rotary tillage (R). In the 2008-2009 growing season, the irrigation treatments were designed as no irrigation(W0), relative water content (RWC) of 80% at sowing, 80% at wintering, 75% at jointing, and 75% at anthesis(W1); RWC of 80% at sowing, 85% at wintering, 75% at jointing, and 75% at anthesis(W2); RWC of 85% at sowing, 80% at wintering, 75% at jointing, and 75% at anthesis(W3); RWC of 85% at sowing, 85% at wintering, 75% at jointing, and 75% at anthesis(W4). In the 2009-2010 growing season, the irrigation treatments were designed as no irrigation(W''0), RWC of 85% at sowing, 85% at wintering, 75% at jointing, and 75% at anthesis(W''3); RWC of 85% at sowing, 90% at wintering, 75% at jointing, and 75% at anthesis(W''4). Under the same irrigation treatment, soil water content in 40-180cm soil layers of RS was lower than that of R practice, whereas the flag leaf photosynthetic rate(P_n), dry matter accumulation after anthesis and its contribution to grain in RS treatment were significantly higher than those in R treatment. Compared with both W4 and W''4 treatments, soil water contents in 60-140cm soil layers of W3 and W''3 treatments were lower at maturity. However, there was no significantly difference among W1, W2 and W3 treatments. Under the same tillage treatment, P_n at late filling stage, dry matter distribution amount in grain at maturity, dry matter accumulation after anthesis and its contribution to grain in W3 and W''3 treatments were significantly higher than those in other treatments, subsequently obtaining higher the grain yield and water use efficiency. In wheat growing environment similar to the condition of this experiment, we propose the best tillage is RS, and the best irrigating regimes are W3 treatment with the precipitation of 13.8 mm from sowing to wintering stage in 2008-2009, and W''3 treatment with the precipitation of 48.1 mm from sowing to wintering stage in 2009-2010.