The Dynamical Change of Soil Water During Dry and Wet Period in Black Soil Zone in Hailun,Heilongjiang Province

Soil water status is an important factor associated to crop growth.Dry period and wet period could be indentified based on precipitation more or less than evapotranspiration in a given period.The dynamical change of soil water in dry period and wet period under no fertilizer(CK),chemical fertilizer(NP) and chemical fertilizer plus manure(NPM),was tested in field experiment in National Field Research Station of Agro-ecosystem in Hailun.Rainfall could infiltrate deeply into 0~170 cm soil depth when cumulative rainfall was 135 mm in given 5 d.And more than 51.5% of rainfall was stored in 0~50 cm soil depth with the increasing order of NPM>NP>CK,indicating that soil capacity to rainfall was improved after manure was applied.However,water stored in 0~150 cm soil profile was consumed when soil water was in dry conditions,at that time evapotranspiration was 98.2 mm greater than rainfall.NPM treatment utilized more water compared to CK and NP.Therefore,Black soil had large capacity in regulating soil water that could be stronger when manure was applied.