Variation Characteristics Of Maize Effective Precipitation And Water Requirement In Liaoning During 1960-2014

Crop effective precipitation and water requirement are the basis for farmland water management and irrigation.Liaoning province is one of the main maize producing areas in our country,. Study on the variation temporal and spatial characteristics of the growing season of maize effective precipitation water requirement in Liaoning province has the important practical significance to irrigation judging by time and places, the water resources sustainable utilization etc.Based on the observation data from 23 meteorology stations during 1960-2014 and phenology data of maize from 20 agrometeorology stations in 20 years nearly over the maize growing regions of Liaoning province, the effective precipitation of maize of the whole growing period and different growth stages during 1960-2014 were estimated by using the reference crop evapotranspiration and precipitation ratio method recommended by Food and Agriculture Organization,and the water requirement of maize also were estimated by using FAO Penman-Monteith equation and crop coefficient method. Using the climate tendency rate method and GIS spatial interpolation method for the analysis of the characteristics of temporal and spatial variation, it showed some conclusions as following:(1).The results showed that the Pe of maize of the whole growing period year’s change and the growing season change reflect significantly during 1960-2014.The annual average of the Pe decreased significantly. From the point of the growing season, Pe is mainly in joining stage.The spatial distribution of Maize Pe shows that "less west more east, less north more south, fromeast to west first decre -asing and then increasing" characteristics, namely:east> south> middle> north> west,which was same with the spatial distribution of precipitation in Liaoning province.(2).The results showed that the ETc of maize of the whole growing period year’s change and the growing season change reflect no significantly during 1960-2014. The spatial distribution of Maize ETc shows that "less north more east, from east to west first decreasing and then increasing" characteristics, namely:south> east> middle> west> north,what’s more,only joining stage is the same to the above,but other stages of maize growing period not.(3).The results showed that the water deficit of maize of the whole growing period year’s change and the growing season change reflect no-significantly during 1960-2014.On the whole the annual average of the water deficit decreased no-signifi -cantly. From the point of the growing season, the water deficit of the most serious occurred in the growth stage of joining stage, sowing stage was more, and maturity stage was least. The spatial distribution of maize effective precipitation shows that "less west more east, less north more south, from east to west first decreasing and then increasing" characteristics, namely: east> south> middle> north> west.Only joining stage is the same to the above, while other stages of maize growing period not.(4).The water of maize all of the growth period can not be met. In the actual production, according to the effective precipitation, water requirement, water deficit of temporal and spatial variation, through the optimization of crop breeding, disease resistance of pest resistant and high temperature resistant varieties, the increase of the multiple crop index, regulating sowing, the adjustment of planting methods (such as plastic mulch), due to such as the time of scientific irrigation methods reasonable planting maize, to achieve regional high and stable yield of spring maize.The results of this study can provide a scientific basis for planting area of maize in Liaoning Province agricultural water use, irrigation, scientific and modern agricultural irrigation area construction.