黑龙江省土壤湿度的气候响应及其与大豆产量的关系

Responses of soil moisture to climate change and relationship between soil moisture and soybean yield in Heilongjiang

利用黑龙江省32个农业气象站1980~2007年作物生长季的旬土壤湿度、月气温和月降水观测资料,采用统计分析方法,分析了研究区表层（0~30 cm）土壤湿度的时空变化特征及其对气温、降水量等气候变化的响应,建立了研究区大豆产量与土壤湿度的关系模型。结果表明：1980~2007年间,黑龙江省不同地区作物生长季表层土壤湿度均呈减小趋势,黑龙江省表层土壤存在干旱化趋向,其中,西部地区尤为明显;20世纪90年代以前,研究区表层土壤处于比较湿润阶段,之后土壤湿度持续降低,并发生了偏干现象;研究期间,黑龙江省作物生长季平均气温呈周期性波动上升,每6 a一个周期,期间小幅波动,1992年开始明显上升;生长季降水量的年际变幅较大,存在一个4~5 a的波动周期;研究区作物生长季表层土壤湿度与气温呈极显著负相关关系,与降水量呈极显著正相关关系（P〈0.01）,气温和降水量是影响黑龙江省作物生长季表层土壤湿度变化的主要气候因素;研究区大豆产量与表层土壤湿度存在极显著的相关关系（P〈0.01）,土壤偏干或偏湿对大豆产量的形成均存在不利影响。

Based on the 1980～2007 observation data of ten-day soil moisture,monthly air temperature,and monthly precipitation during crop growth season（from May to September） from 32 agro-meteorological stations in Heilongjiang Province,the spatiotemporal variation of surface soil（0～30 cm） moisture and its responses to the air temperature and precipitation in the study area were analyzed by using statistical method,and the model for analyzing relationship between soybean yield and soil moisture was built by use of regression methods in the study area.The results showed that in Heilongjiang,the surface soil moisture during crop growth season in 1980～2007 had a decreasing trend,and tended to be aridified, especially in the west parts.Before the 1990s,the surface soil was relatively humid,but thereafter,the humidity kept decreasing,and partial dryness occurred.In the study period,the mean air temperature during crop growth season had a periodical increase before 1992,with a small fluctuation in a cycle of 6 years,but increased obviously after that.The precipitation during crop growth season had a larger inter-annual variation,with a cycle of 4～5 years.The surface soil moisture during crop growth season was significantly negatively correlated to air temperature and positively correlated to precipitation.Both air temperature and precipitation were the main climatic factors affecting the variation of surface soil moisture in Heilongjiang.Soybean yield was significantly correlated to the surface soil moisture in the study area,and partial dry or wet soil had a adverse influence on soybean yield.