| 摘要: |
| 【目的】探究区域尺度冬小麦产量与水分利用效率对灌溉定额和农田蒸散量的响应。【方法】基于分布式农业水文模型SWAP-WOFOST已获得的现状灌溉情景、10种限水灌溉情景和雨养情景下的20个轮作周年的模拟结果，考虑冬小麦生育期3种降水水平和7种土壤质地剖面（STP），分别量化冬小麦产量（Y）、农田蒸散量（ET）和水分利用效率（WUE）对灌溉定额（I）的响应以及Y和WUE对ET的响应。【结果】在3种降水水平和7种STP类型下，与现状灌溉情景相比，I每减少1 mm，Y、ET和WUE分别降低5.40~19.26 kg/hm2、0.51~0.90 mm和1.46×10-3~3.78×10-3 kg/m3，Y和WUE下降程度较小的情况出现在通体砂质土和上壤下砂土分布且现状灌溉情形下Y和WUE偏低的区域。当I不超过现状灌溉情形时，Y与ET呈线性正相关；在丰水期和平水期，WUE与ET之间的关系以二次函数为主；而在枯水期，WUE随ET的增加而增加。【结论】在减少现状灌溉定额的情况下，维持相对高的产量和WUE较难，限水灌溉应优先实施在砂质土壤分布且现状Y和WUE较低的区域；在丰水期和平水期，通过减少ET来提高WUE具有可行性。 |
| 关键词: 限水灌溉；产量；水分利用效率；SWAP-WOFOST模型；土壤质地；降水水平 |
| DOI：10.13522/j.cnki.ggps.2023318 |
| 分类号: |
| 基金项目: |
|
| The effect of irrigation amount and evapotranspiration on regional-scale winter wheat yield and water use efficiency |
|
WANG Haodong, LI Pei
|
|
1. Chang’an University, School of Water and Environment, Xi’an 710054, China;
2. Hebei Cangzhou Groundwater and Land Subsidence National Observation and Research Station, Cangzhou 061000, China
|
| Abstract: |
| 【Objective】Limiting extraction of groundwater for irrigation is a strategy proposed to alleviate the imbalance between water shortage and crop demands and sustain wheat production in northern China. Understanding the responses of yield (Y) and water use efficiency (WUE) of wheat to irrigation amount (I), evapotranspiration (ET) and spatiotemporal heterogeneities of other factors is essential to minimizing yield loss due to the implementation of the strategy. This paper addresses this based on modelling.【Method】Using the SWAP-WOFOST model, we simulated wheat-water interactions continuously for 20 years under the current irrigation schedule, ten limited irrigation scenarios and rain-fed management. We compared seven-textured soils and three precipitations levels, from which we calculated the relationships between Y and I, ET and I, WUE and I, Y and ET, WUE and ET.【Result】For the three precipitation levels and the seven textured soils, compared with the current irrigation schedule, decreasing I by 1 mm reduced Y, ET and WUE by 5.40-19.26 kg/hm2, 0.51-0.90 mm and 1.46×10-3-3.78×10-3 kg/m3, respectively. In areas where the current Y and WUE are low and the whole soil profile is sandy or the topsoil is sandy and the subsoil is loamy, decreasing I did not result in decreases in Y and WUE as significantly as in other areas. When I was lower than current value, Y and ET are linearly correlated. In wet and normal years, the relationship between WUE and ET was quadratic, while in dry years, WUE increased with ET.【Conclusion】At regional scale, it is difficult to maintain both high yield and high WUE when the irrigation amount is reduced. The implementation of the limited irrigation can prioritize the areas where the soils are sandy and the yield and WUE of wheat are currently low. There is also a potential to increase WUE by reducing ET in wet and normal years. |
| Key words: limited irrigation; yield; water use efficiency; SWAP-WOFOST model; soil texture; precipitation level |
