三江平原白浆土水分状况的研究——白浆土水分周年动态及其对农业生产的影响(二)

为了说明土壤供水与作物需水之间的关系，将观测年度4-9月土壤有效水量(土壤含水量与萎蔫系数之差)和易效水量（土壤含水量与毛管联系断裂水量之差）列于表4。作物各生育期的蒸散量（叶面蒸腾与土面蒸发之和）是难以测定的。这里我们采用布莱尼法计算作物耗水量，权资参考。布莱尼——克利德尔公式：

Research on soil moisture conditions of Albic Planosol in the "Three River Plain

A five years' (1980--1984) continous monitoring or soil moisture or hillock albicPlanosol and plain albic planosol was undertaken on the southern side of wanda Mt.,Three River plain,Heilongjiang Province. The soil layrs under inspection were 0-100cm totally. The purpose of the research were to observe the annual fluctuation of soilmoisture and their influences on crop growth; to find out the way of soil reclamationand resistence to the drought and flooding in agriculture. This work was based on thepreceeding reseach of soil moisture monitor carried out from 1962-1966 of continuousObservation.Through the interrelated analysis of moisture fluctutions in different soil layers,to find out their moisture connections; to compare the soil moisture fluctution with wa-ter requirement of crope,and the contradiction of water supply to water demend.In the spring-drought period,it must pay attention to the utilization of melting icewater in the sub-layer soil,and to reduee moisture evaporation. The autumn loggingdays always inhibit crop growth and havesting. And because soil moisture imput andout are nearly balanced for the whole year,the drainage must be controlled and drainthe surface water oulyFOr improvement of albic Planosol and increasing compound benifit,a rational ro-tation system both for land and reclamation of soli is required,and animal husbandrymust be included in the system.