太湖地区典型水稻土水力学特征及土壤库容研究

Hydraulic Characteristics and Soil Reservoir Capacity of Typical Paddy Soil in Taihu Lake Region

针对气候变化条件下温度升高对土壤水分产生的影响,选择太湖地区典型水稻土——乌栅土作为研究对象,对其土壤的水力学特征及土壤库容进行了研究。结果表明:(1)影响乌栅土水分特征曲线的主要因素是容重与黏粒含量。饱和条件下和水吸力达到1.50×106 Pa时各土层的含水量(凋萎含水量)变化均表现为:耕作层>犁底层>潴育层>潜育层。(2)乌栅土的有效水含量与容重和黏粒含量呈显著负相关关系,与孔隙度呈显著正相关关系。(3)在土壤的各种理化性质中,容重和总孔隙度是影响饱和导水率的主要因素,而毛管孔度与pH值为次要因素。(4)乌栅土耕作层总库容为91.48mm,有效水库容为22.02mm,滞洪库容为20.50mm,这种土壤具有良好的水分状况,既能保证太湖地区粮食作物的稳产高产,又具一定的蓄水调节功能。

With climate change,temperature increase may affect soil moisture movement and content.Take the typical paddy soil（Wushan soil） as a study case,the water characteristics curves and soil reservoir capacity of Wushan soil were studied.The results were as follows：（1） Main factors affecting the water characteristics curves were bulk density and clay content.Soil water content decreased in following order： plough layer,plowpan,waterlogging-hydromorphic layer,and gley layer under saturated condition and water suction as 1.50×106 Pa（wilting point）.（2） Available water content had significant negative correlation with bulk density and clay content.But it had significant positive correlation with porosity.（3） Bulk density and total porosity were the main factors impacting the saturate hydraulic conductivity while the capillary porosity and pH were the second factors.（4） Total reservoir capacity of Wushan soil in plough layer was 91.48 mm.Available water reservoir capacity was 22.02 mm,and the flood detention reservoir capacity was 20.50 mm.Therefore,this soil had good water status which not only guaranteed high and stable soil productivity,but also had a regulatory function of water storage.