• 论文 •

### 作物生产、水分消耗与水分利用效率间的动态联系

1. 中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室
• 收稿日期:1997-05-13 修回日期:1997-08-18 出版日期:1998-03-25 发布日期:1998-03-25
• 作者简介:刘文兆,男,1960年11月生,研究员。1982年毕业于西北大学地理系,同年分配到中国科学院水土保持研 究所工作,1992年2月至1993年10月在加拿大莎斯喀彻温大学做访问研究。现为中国土壤学会土壤物理专 业委员会副主任,陕西省土壤学会理事。研究方向为土壤水分与作物关系及SPAC中水分运移,目前主持课题 包括国家自然科学基金项目、中科院西部之光项目及国家九五科技攻关安塞试区专题等。在国内外发表 论文20余篇。
• 基金资助:

国家自然科学基金

### DYNAMIC INTERRELATIONS OF CROP PRODUCTION,WATER CONSUMPTION AND WATER USE EFFICIENCY

LIU Wenzhao

1. Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling,Shaanxi 712100
• Received:1997-05-13 Revised:1997-08-18 Online:1998-03-25 Published:1998-03-25

Abstract: This paper introduces the concepts of marginal water use efficiency (MWUE) and elasticity of water production (EWP),and reveals dynamic interrelations of crop production and water consumption and water use efficiency (WUE) based on the functional relation between water consumption and crop yield ( or photosynthate). Providing the relation of seasonal evapotranspiration (ET) and crop yield (Y) is as Y=f(ET),then WUE=Y/ET,MWUE=dY/dET,and EWP=MWUE/WUE.WUE increases with the rise of ET if EWP>1 and decreases with the rise of ET if EWP<1. Proper construction of the function of crop water production,Y=f(ET),serves as a basis for correct analysis of WUE. If the Y=f(ET) function is linear,the changing trend of WUE with ET is directly affected by the constant term. If the Y=f(ET) function is quadratic parabolic,the maximum WUE comes earlier than the maximum yield with the rise of ET. The ET that makes WUE reach to its maximum value equals the arithmetic square root of a ratio of the constant term to the coefficient of quadratic term(). WUE increases with the rise of ET when ,conversely WUE decreases with the rise of ET when . Field experiment on spring corn yield response to water and fertilizer in the loess tableland of China showed that the form of Y=f(ET) appeared parabolic relationships at both high and low fertility levels,and high fertility plots had higher WUE and ET than low fertility ones under the same level of water supply. At high fertility plots in 1987,WUE increased with the rise of ET when ET< 472mm,reached to the maximum value of 16 3kg/ha.mm when ET =472mm,and decreased with the rise of ET when ET<472mm. The yield reached the maximum of 8 111kg/ha when ET = 524mm. MWUE always decreased with the rise of ET within the experimental range and dropped to zero when ET = 524mm. At low fertility plots,WUE reached the maximum value of 11 6kg/ha.mm when ET =436mm,and the maximum yield of 5 298kg/ha was gained when ET = 485mm; the WUE and the MWUE were similar to the ones of high fertility plots in the aspect of the changing trend.