水保所知识产出(1956---)知识库

【目的】通过黄土塬区播前底墒变化和生育期差别供水（降水+补充灌溉）对冬小麦产量、耗水量
以及水分利用效率影响的田间试验，揭示该区域农田有限水资源高效利用的调控机制，明确现有措施下冬小
麦旱作生产潜力可实现水平。【方法】划设田间试验小区，在夏闲期通过覆盖保水与生物耗水措施形成底墒差
异的基础上，设计如下试验：（1）由不同底墒+生育期降水形成4 个冬小麦全生育期无补灌处理，以分析冬小
麦产量及水分利用效率对播前底墒变化的响应。其2 m 土层底墒变化范围为350—550 mm。（2）相同底墒下
不同生育期灌一水处理：在平均底墒约为500 mm 下分别在拔节期、孕穗期和灌浆期补充灌溉40 mm，探讨冬
小麦不同生育期对等量灌溉的响应差别。（3）高底墒542.3 mm 与571.6 mm 下分别进行灌2 水与4 水处理，
形成冬小麦全生育期比较充分的供水条件，研究冬小麦在低水分胁迫下产量提升的可能程度及其水分利用效
率特征。【结果】（1）在黄土塬区降水季节分布特征下，播前底墒对冬小麦产量具有决定性作用，产量随底墒
线性增加。在做好夏闲期蓄水保墒的基础上，旱作冬小麦产量可达到充分供水情况下能够取得产量的88%—
90%水平。（2）与2 m 土层底墒为500 mm 且生育期无补充灌溉的处理比较，供水增加同为40 mm 时，表现为
底墒增加处理的产量提高了11.8%，次之是在拔节期与孕穗期分别补灌的处理，但三者间产量无显著差异；
播前底墒较高并在拔节期及孕穗期补充灌溉的处理冬小麦产量达到试验年份较高水平，且作物水分利用效率
（WUE）也得到提高。（3）冬小麦产量与耗水量表现为Logistic 曲线关系，随着耗水量的增大，产量提升速
率表现为先快后慢，边际水分利用效率（MWUE）则持续降低，而WUE 表现为上升、达到峰值和下降三个阶段，
且WUE 到达其最高值的耗水量小于产量到达其最高值的耗水量。【结论】黄土塬区气候条件下，播前底墒差别
与生育期差别供水对冬小麦产量均有影响，由底墒或不同生育时期分别增加等量供水在总供水水平相同时其
增产效应基本一致；采用Logistic 曲线模型可以较好地模拟冬小麦产量与耗水量之间的关系，揭示产量、耗
水量及WUE 间的内在联系。

【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.