1982-2012年来杭州市郊水稻田有机质变化特征及其调控措施

目的]了解杭州市郊水稻田土壤有机质的长期演变，为杭州市正在推进的精品化、高度集约化农业生产提供土壤肥力的精确管理依据。方法]利用历史资料和近期土壤质量调查数据探讨了近30 a 来杭州市郊水稻田土壤有机质的变化特征。结果]从1982—2012年，杭州市郊水稻田土壤有机质含量总体呈下降趋势，平均降幅为2．95％，但各土种有机质变化有所差异。其中，培泥砂田、小粉田、黄斑田、泥砂田和粉泥田的土壤有机质呈现增加趋势，特别是培泥砂田，土壤有机质含量增幅高达22．86％；而青紫泥田、青粉泥田和黄松田的土壤有机质呈现下降趋势，且青紫泥田土壤有机质含量降幅高达22．59％。结论]近30 a 来，杭州市郊水稻田土壤有机质发生了较大变化，但其变化程度和变化方向因土壤种类而异。施肥结构、耕作方式及耕作制度是引起土壤有机质变化的主要原因。

Changing Characteristics and Improvement Measures of Soil Organic Matter in Paddy Land of Hangzhou Suburb During 1982-2012

Objective] We investigated the variations of soil organic matter in paddy land of Hangzhou suburb over the last 30 years in order to provide basis for accurate soil fertility management and high intensive agricultural production.Methods] Historic materials and current soil quality survey data were collected and compared to investigate the variations of soil organic matter.Results] From 1982 to 2012, the mean content of soil organic matter decreased by 2.95%. The changes of soil organic matter varied with soil types. The mean content of soil organic matter in culture muddy-sandy field, silt paddy land, Fe-accumuli-stagnic anthrosols, muddy-sandy field and silt loamy paddy land showed an increasing trend, especially, in culture muddy-sand field, soil organic matter increased by 22.86%. In contrast, the mean content of organic matter in degleyed clayey paddy soil, blue silt loamy paddy soil and yellow loamy paddy soil showed a decreasing trend, and this decreasing trend in degleyed clayey paddy soil reached to 22.59%.Conclusion] The content of organic matter in the paddy soils changed greatly during the past 30 years, and this change varied among different soil types. Fertilization structure, tillage practices and farming system were the main reasons that cause the variations of soil organic matter.