干旱环境下春小麦最优调亏灌溉制度确定

以河西绿洲灌区春小麦调亏灌溉2年的平均产量、水分利用效率、供水效率和2年后的土壤养分综合指标4个单项参评因子为参数建立单因子评判矩阵,对干旱环境下春小麦调亏灌溉制度进行了综合评价。结果表明,调亏灌溉处理的综合评价指标以HFF处理最高,其次为MFM处理,而以LLL处理最低,但所有调亏灌溉处理综合评价指标均显著高于高水分处理FFF。因此,无论是从作物生产力、水资源利用效率还是水资源和土壤养分的可持续利用方面来说,HFF处理调亏灌溉模式均因其最高的作物生产力和水分利用效率、较高的供水效率(为最大值的96.3%)及较高的土壤养分综合指标(为最大值的97.7%)而具有最高的综合评价指标,成为试区推荐的春小麦全生育期最优调亏灌溉模式,即春小麦孕穗和抽穗期及灌浆—生理成熟期均高水分处理(65%~70%田持)而拔节期重度水分调亏(45%~50%田持),其灌溉定额为440 mm左右(包括晚秋季储水灌100 mm)。

Optimized Irrigation Regime of Regulated Deficit Irrigation in an Arid Environment

In this study the two years of average grain yield(y),water use efficiency(WUE),water supply use efficiency(WsUE),and the integrated nutrient index(INI)after two years of regulated deficit irrigation(RDI)in spring wheat in Hexi oasis irrigation region were used as the factors to establish the single-factor-evaluation matrix in integrated evaluation of RDI regimes in an arid environment.The results showed:The maximum IEI in RDI treatments occurred in HFF followed by MFM,then MFH.The IEI in treatment HFM and MFL were obviously lower than that in MFH,and that in LLM was significantly lower than that in MFL,while the minimum IEI occurred in LLL treatment.Anyway,IEI in RDI treatments were all significantly higher than in the FFF check subjected to free-from-water-deficit.Consequently,no matter in the crop productivity,water resources use efficiency,and sustainable utilization of water resources and soil nutrients,RDI regime HFF had the maximum IEI due to its maximum crop productivity and water use efficiency,higher water supply use efficiency(reaching to 96.3% of the maximum)and integrated nutrient index(97.7% of the maximum).As a result,RDI treatment HFF was recommended as the optimized regime for spring wheat throughout wheat growing season,in which wheat was to be subjected to free-from-water-deficit(soil water content,ie.,SWC maintained at 65% to 70% of the field capacity)during booting and heading and grain filling to physiological maturity while high water deficit(SWC maintained at 45% to 50% of the field capacity),with the total irrigation water amounting to 440 mm(including 100 mm during late autumn).