南亚热带丘陵土壤水分循环及其有效性的研究──Ⅱ.丘陵赤红壤水分循环动态特征

Studies on Water Cycle and Its Availability of Latored Soils in Hills of South Subtropics──Ⅱ.The Characterisics of Water Cycle of Latored Soils

根据定位观测资料，阐述了南亚热带丘陵赤红壤水分循环的动态特征。研究结果表明，南亚热带丘陵赤红壤贮水量存在年际变化和显著的季节变化：雨季（4～9月）土壤贮水量相当于田间持水量的90％以上，个别月甚至超过贮水库容量。但旱季月土壤贮水量低，相当于田间持水量的50％～80％，需要补充水分才能及时满足植物所需的水分。

Based on the observational data from the positioning experimental plots,this paper sets forth the dynamic characteristics of water cycle of latored soils in the south subtropics.Results show that,being controlled by rainfall distribution,the available water content of latored solls presented clear annual and seasonable changes.In rainy season,soil avaiable water content of latored soils was equal to 70% or more of the available water-holding capcity,while dry season,soil available water content of latored soils was only as much as 12% to 80% of the available water-holding capcity.Therefore,it is suggested that,in order to satisfy the need of plant growth,extra water should be provided with spray imigation in dry season.