Proposed revision to the FAO procedure for estimating crop water requirements

被引：15

作者：

Allen, RG ^{[1
]}

Smith, M ^{[1
]}

Pereira, LS ^{[1
]}

Pruitt, WO ^{[1
]}

机构：

[1] Utah State Univ, Logan, UT 84322 USA

来源：

SECOND INTERNATIONAL SYMPOSIUM ON IRRIGATION OF HORTICULTURAL CROPS, VOLS 1 AND 2 | 1997年 / 449期

关键词：

evapotranspiration; evaporation; crop-water use; guidelines;

D O I：

10.17660/ActaHortic.1997.449.2

中图分类号：

S3 [农学（农艺学）];

学科分类号：

0901 ;

摘要：

The forthcoming revision of the FAO ID-24 publication (Crop Water Requirements) utilizes the FAO form of the Penman-Monteith equation to predict grass reference evapotranspiration (ET) and includes modified procedures for estimating crop coefficients (K-c). The K-c of the initial growing period has been reexpressed using an integrated, volumetric-based decay equation to describe the effect of the surface soil water balance on evaporation. The K-c table of the original FAO ID-24 publication, which had multiple entries for four wind-relative humidity classes, has been condensed into one column representing K-c's for conditions of low wind and moderate relative humidity. K-c's for other climatic conditions are derived using an equation containing wind speed and relative humidity. Procedures are introduced for applying FAO K-c's as "basal" coefficients, where increases in K-c during evaporation from wet soil are computed using decay functions based on a moisture balance of the soil surface.

引用

页码：17 / 33

页数：17