【Objective】A field experiment was carried out to study the influence of soil water storage before sowing anddifferent water supplies (precipitation + supplemental irrigation) during a growing period on wheat yield, water consumption and
water use efficiency, to reveal the regulation mechanism of effective utilization of limited water resources in farmland, and to make
clear the achievable level of dryland production potential of winter wheat under the existing measures in the Loess Tableland.
【Method】Field experimental plots were designed as follows, based on different soil water contents achieved by either covering the
plot or growing a crop in the summer fallow period. (1) In order to analyze the response of wheat yield and water use efficiency to
the change of soil water storage before sowing, four rain-fed treatments with different soil water storage levels were formed in the
whole growth period of winter wheat. The water storage in 2 m soil profile changed in the range of 350 - 550 mm. （2）Under the same
average soil water storage of 500 mm, 3 respective treatments with one time irrigation of 40 mm at jointing stage, booting stage or
filling stage were applied to explore different responses of equal irrigation at different growth stages of winter wheat.（3）Under the
high water storage levels of 542.3 mm and 571.6 mm, treatments of 2 times and 4 times irrigation were carried out, respectively, to
study the possible increase of winter wheat yield and the features of water use efficiency under low water stress.【Result】(1) Under
the seasonal distribution of precipitation characteristics of Loess Plateau, the soil water storage before sowing had a decisive effect
on wheat yield, and wheat yield increases linearly with the soil water storage. When soil water is well conserved in the summer
fallow period, the yield of winter wheat in dryland farming can reach 88% - 90% level of wheat yields under sufficient water supply.
（2）Compared with the treatment of 500 mm water storage in the 2 m soil profile and no supplemental irrigation, per increase of 40
mm water supply yield increased by 11.8% for the soil water storage increase, followed by irrigation at the jointing stage and booting
stage respectively. However, no significant differences between the three treatments were detected. The winter wheat yield of the
treatment with higher soil water storage before sowing and 2 times irrigation in both the jointing stage and booting stage reached a
high yield level in the test years with a high WUE. (3) There was a Logistic relationship between yield and water consumption. With
the increase of water consumption, the yield increased fast at first and then slowly; the marginal water use efficiency (MWUE)
declined continuously; WUE showed three stages of change: rising, peak and falling; and the water consumption at the maximum
WUE was less than that at the maximum yield . 【Conclusion】Under the climate condition of the Loess Plateau, both the soil water
storage before sowing and different water supply during a growing period influenced the yield of winter wheat. Equal incremental
water supply by soil water storage or irrigation in different growth periods had basically the same effect on yield when the total water
supply was the same. The relationship between yield and water consumption of winter wheat could be simulated by a Logistic curve
model that can be used to reveal the intrinsic relationships among yield, water consumption and WUE.
李超,刘文兆,韩晓阳,等. 黄土塬区冬小麦产量及水分利用效率对播前底墒变化 与生育期差别供水的响应[J]. 中国农业科学,2017,50(18):3549-3560.