亏缺灌溉对冬小麦生理生态指标的影响及应用

Effects of deficit irrigation on physio-ecological indices of winter wheat

华北平原是资源性缺水的地区,同时又是我国粮食的主产区。如何利用有限的水资源发展农业生产是该地区面临的主要问题。亏缺灌溉是一种新的灌溉制度,是在产生较高经济价值的前提下,科学合理地利用水资源。本文阐述了中国科学院栾城农业生态系统试验站多年以来在亏缺灌溉对冬小麦根系、冠层结构、干物质生长、产量及水分利用效率等生理生态指标影响方面的研究进展。亏缺灌溉可以明显影响冬小麦根系在土壤中的分布,并通过水分调节叶片的气孔,进而影响光合产物,优化冬小麦的干物质生长和分配,最终实现最高的经济产量。多年不同供水条件下田间连续试验和控制性盆栽试验的研究结果显示,拔节期是冬小麦对水分比较敏感的时期,不宜进行亏缺灌溉,其他时期可以进行适度的亏缺灌溉。同时,根据研究结果优化了冬小麦季的灌溉制度,提出在干旱年灌溉3水、平水年灌溉2水和丰水年灌溉1水的灌溉制度,次灌溉水量在60-70 mm之间。

Water shortage is the main limitation to agricultural productivity in the North China Plain — a main grain production base in China.It has therefore been a major research task to develop an agricultural production practice that uses limited fresh water resources in the region.Deficit irrigation is a new irrigation scheme that optimally uses water resources while maintaining high eco-nomic yield.This paper reviewed the effects of deficit irrigation on physio-ecological indices of winter wheat at the Luancheng Agro-Ecosystem Experimental Station of Chinese Academy of Sciences.Field plot irrigation experiments had shown that different levels of deficit irrigation at different growth stages of winter wheat affected root size and distribution in the soil profile,canopy structure,biomass growth,grain yield,and water use efficiency.The experiments showed that different levels of deficit irrigation facilitated leaf stomata adjustment which in turn affected the photosynthetic products and distributions of dry matter.The highest grain yield was obtained under optimal deficit irrigations at the different growth stages.This implied that the levels of deficit irriga-tion were different at different growth stages of winter wheat.The deficit sensitivity index was highest at jointing stage,when was not suitable time for deficit irrigation.In other words,deficit irrigation at other growth stages like the recovering and grain-filling stages little affected grain yield and therefore resulted in high water use efficiency.Based on the above results,an optimal irrigation scheme was developed in relation to the trend in precipitation leveling the region — i.e.,1,2 and 3 times of irrigation at about 60-70 mm every time in wet years,normal years and dry years,respectively.The optimal irrigation scheme had been widely used in the North China Plain region.