地下水位及有机肥对红壤性水稻土有机碳活性组分的影响

利用自1981年开始的红壤性水稻土长期定位试验,对耕层土壤有机碳活性组分、孔隙状况及团聚体进行分析,以探究不同地下水位(20、80 cm)和施肥(高量有机肥、常量有机肥、化肥)管理对红壤性水稻土有机碳活性组分的影响,并分析孔隙状况和团聚体对土壤有机碳活性组分的作用关系.结果表明:降低地下水位导致高量有机肥和化肥处理的轻...

Effects of Underground Water Table and Organic Manure on Labile Carbon Fractions in Red Paddy Soil

A long-term field experiment was conducted since 1981 in order to explore the effects of underground water table and organic manure on labile carbon fractions (light fraction organic carbon, LFOC; easily oxidized carbon, EOC; and particulate organic carbon, POC) as well as the interaction relation of aggregates and porosity on labile carbon fractions, the treatments included two underground water tables of 20 cm and 80 cm, applying organic manure with a high rate (HOM) and a normal rate (NOM), and applying chemical fertilizer (CF). The results showed that lowering underground water table resulted in significant lower content of LFOC and POC under NOM and CF, and the contents of EOC were increased significantly under different treatments; long-term application of organic manure significantly increased the contents of LFOC, EOC and POC. Two-way ANOVA revealed that the fertilization had a greater effect on labile carbon fractions than underground water table. The increased content of macro aggregates in red paddy soil could promote the formation of capillary pores, which protected or stabilized LFOC and POC; however, no obvious effect of porosity and aggregates on EOC was observed. Therefore, it is necessary to pay attention to the change of groundwater level and the rational application of organic manure in soil organic carbon management and fertility regulation of paddy fields in south China.