甘肃省土壤农业水文特性的研究

A STUDY ON AGRO-HYDROLOGICAL CHARACTERISTICS OF SOILS IN GANSU PROVINCE

本文在研究甘肃省土壤容重、土壤凋萎湿度和田间持水量的时空分布规律及其相关因素的基础上,根据占田间持水量40％(严重干旱)、60％(轻度干旱)和80％(最适宜)时的土壤湿度标准,计算出5种地域类型26个代表点的不同土壤湿度标准的土壤水分界限值,为各地采取不同的农业耕作和管理措施提供依据。最后以凋萎湿度为主导指标,以容重和田间持水量为辅助指标,建立甘肃省土壤农业水文特性分区指标系统,把全省划分为5个大区12个副区,对各大区土壤农业水文特性值进行了评述,并提出土壤改良措施和相应的办法。

This paper first studied the distribution laws of soil bulk density, wilting moisture of soil and field capacity in terms of time and space and the facters related to them. Then according to the standard of soil wetness which defines 40 per cent of the field capacity as heavy drought, 60 per cent as and 80 per cent as optimum, we have calculated the threshold values of soil moisture of various sail wetness for twentysix representative points in five districts. This vvill provide foundations for adobting different agricultural cultivation methods and managerial measures at different localities. In the end, a regionalization index system of agro-hydrological characteristics of soil has been set up for Gansu province by using the wilting moisture of soil as the leading index and the bulk density and field capacity as auxiliary indices. According to the regionalization index, we divided the whole province into five broad regions and twelve subre-gions, discussed the agro-hydrological characteristics of soil in each broad region, and put forward the appropriate measures for soil reclamation.