关键词: 春玉米, 作物需水量, 缺水量, 有效降水量

Abstract:

Based on the maize observational data and meteorological data from 5 meteorological observation stations in Shenyang of Liaoning Province during 1960-2016, the water requirement and effective precipitation in spring maize growing season and different growth stages were estimated. Further, the crop water surplus deficit index (CWSDI) at each growth stages of spring maize were calculated and analyzed in the study area. The results show that the effective precipitation during the whole growing period and different growth stages of spring maize decreased from 1960 to 2016 except the period from sowing to emergence, emergence to seven leaf and jointing to tasseling. The water requirement at each growth stage declined over the past 57 years. The water deficit decreased during the whole growing period, especially at growth stage of jointing to tasseling over the past 57 years, followed by the periods from sowing to emergence and emergence to seven leaf. There was a significant north-south difference about effective precipitation which generally increased from north to south, but the water requirement was high in the north and low in the south. Besides, the northern region was the high area of water deficit. Comparing the water deficit at different growth stages of spring maize, it was found that the most serious water deficit occurred at the growth stage of jointing to tasseling.

Key words: spring maize, water requirement, water deficit, effective precipitation