陇东旱地水肥产量效应研究

The Study of Effects of Water and Fertilizer UPon Wheat Yields in Rainfed Land in the East Gansu

在陇东旱地的典型代表高干试验区,1985～1990年两处进行定位试验研究,从不同施肥状态下的水肥效应看,氮磷肥配合农家肥是增产、提高水分生产率的主要途径,水分生产率从0.34提高到0.80kg麦/mm水。从不同供水条件下的肥水效应看,在底墒不足情况下,充分发挥肥料的促根调水作用,也能获得较高产量和较高水分利用率。从不同施肥和不同供水条件下的冬小麦产量反应看,肥料因素比水分因素对产量的贡献大。证实当前在陇东一年一熟半湿润易旱农区的主要限制因子是肥力,水分因子次之。另外,通过对麦田水分供需平衡的分析表明,陇东旱地水分在底墒正常年份亏缺69mm左右,产量降低值为14.2%左右。水分满足率85.1%,对供水过程的分析表明陇东旱地土壤供水有效性高,供水层深厚(为2m以下)。

The fixed position tests were conducted in two places in Gaoping Experiment Areathe typical rainfed land of the east Gansu in the years of 1985～1990.Viewing the ef-fects of moisture and fertilizer upon wheat yields from different cases of fertilizer appli-cations,N and P fertilizer in matching with farm manure fertilizer will promote yield in-crease,and also be an important approach to improve moisture production efficiency.Inthe case of lack of base moisture,the function of fertilizer to encourage root develop-ment and regulate water must be further brought into full play,which can also ensurehigh yields and improve moisture productive efficiency.Viewing the yield of winterwheat from different fertilizer applications and different moisture supply conditions,fer-tilizer component makes greater contribution to the yield increase than moisture condi-tions,thus,further testifying to the fact that the important constraint in yield increaseis soil fertility,and moisture is the next in importance in the semi-humid area liable todroughts with one crop a year in the east Gansu.In addition,the analysis of the balanceof water needs and supplies in wheat fields showed that in the normal year,base mois-ture in reinfed land in the east Gansu lacks 69 mm or so,and yield reduction is 14.2% ofso.Moisture required rate can be 85.1%.The analysis of water suppling processshowed that soil moisture supply in rainfed land in the east Gansu is highly effectivewith deep water supply layer(below 2 meters under ground).