咸淡水交替灌溉对冬小麦生长及产量的影响

Effects of Alternate Irrigation with Fresh and Brackish Water on Winter Wheat Growth and Yield

【目的】探究不同咸淡水交替灌溉方式对冬小麦生长及产量的影响,并通过通径分析在高产的基础上选择适宜冬小麦的咸淡水交替灌溉方式。【方法】采用避雨测坑试验,灌溉咸水矿化度设为1、3、5 g/L NaCl,以全生育期灌溉淡水(0.12 g/L NaCl)为对照(CK),分别在冬小麦的拔节-抽穗期、抽穗-开花期、灌浆期设置咸-淡-淡(BFF)、淡-咸-淡(FBF)和淡-淡-咸(FFB)3种咸淡水交替灌溉方式,研究了冬小麦生长指标、产量及其构成因子。【结果】BFF处理对冬小麦生长及产量具有较大的抑制作用,其次是FBF处理,FFB处理影响最小。在相同的咸淡水交替灌溉处理下,微咸水矿化度越大,对冬小麦生长及产量抑制作用越大;通径分析表明对冬小麦产量形成直接影响最大的性状是穗粒数,决策系数为0.697 0,其次是秸秆质量、千粒质量和穗数,决策系数分别为0.377 5、0.322 8和0.286 6,株高和单株地上干物质累积质量对冬小麦产量影响较小。【结论】在灌浆期采用较低矿化度微咸水灌溉对冬小麦穗粒数、秸秆质量、千粒质量和穗数影响不明显,从而对产量影响较小,因此在冬小麦拔节-开花期采取淡水灌溉并于灌浆期转换为3 g/L微咸水灌溉,可保证较高产量并实现微咸水资源的合理利用。

【Objective】The purpose of this paper is to explore the effect of different alternate irrigation methods of brackish and fresh water on winter wheat growth and yield, and the path analysis was tested to select a suitable alternate irrigation method of brackish and fresh water for high production of winter wheat.【Method】The experiment was conducted in lysimeters under the rain shelter. Brackish water was treated with 3 different salinities(1,3, 5 g/L NaCl). Fresh water(0.12 g/L NaCl) irrigation throughout the whole growth period was used as the control group. Three alternate irrigation methods of brackish and fresh water, i.e., brackish-fresh-fresh(BFF), freshbrackish-fresh(FBF) and fresh-fresh-brackish(FFB), were set up at jointing-heading stage, heading-flowering stage and filling stage of winter wheat, respectively. The influence of alternate irrigation on wheat growth, yield and yield components was studied.【Result】BFF treatment had a greater negative effect on the growth and yield of winter wheat, followed by FBF treatment, and FFB treatment had the least effect. Under the same alternate irrigation method, brackish water with higher salinity caused greater inhibition on winter wheat growth and yield.Path analysis results revealed that the traits that had the greatest direct impact on the yield formation of winter wheat were the number of grains per spike, with a decision coefficient of 0.697 0, followed by straw weight, 1000-grain weight and number of spikes, with decision coefficients of 0.377 5, 0.322 8 and 0.286 6, respectively.Plant height and accumulated dry matter per plant had little impact on the yield of winter wheat.【Conclusion】Irrigation with low salinity brackish water has no obvious effect on grain number per spike, straw weight, 1 000-grain weight and spike number of winter wheat during grain filling stage, thus having little effect on yield. Therefore, fresh water irrigation from jointing to flowering stage and conversion to 3 g/L brackish water irrigation during grain filling stage can ensure higher yield and realize reasonable utilization of brackish water resources.