Variation of Minimum Water Requirement for Plants in the Yellow River Basin
Access this Article
The crop water requirement was estimated by using the evapotranspiration estimation model and soil water balance model at a semi-arid region in the Yellow River basin from 1990-2000. We separately estimated the evapotranspiration at growing periods and non-growing periods. During the growing periods, we estimated evapotranspiration by the Hergreaves model and crop coefficient for maize, and during the non-growing periods, we estimated evaporation by the Priestly-Taylor method and the equation of Davis and Allen. The soil water balance model was the water budget model. The minimum of the crop water requirement was 380mm in 1992 and the maximum was 600mm in 1997. The minimum rainfall was 210mm in 2000 and the maximum was 375mm in 1992. In dry years, the additional irrigation water needed is more than 2.5 times as much as the rainfall. The stage when additional irrigation water is needed most is of the crop development stage. The days of water deficit are 44 days and this means that almost every day suffers from the water deficit.
- Journal of Agricultural Meteorology
Journal of Agricultural Meteorology 60(5), 1017-1020, 2005
The Society of Agricultural Meteorology of Japan