长期施肥对土壤生物活性有机碳库的影响

采用土壤培养实验方法,研究了25年施肥对平凉黑垆土土壤生物活性有机碳库(C0)的影响。结果表明:土壤生物活性有机碳库(C0)以施用有机肥处理显著增大,其中以S+NP处理最高,达1071.00μg/g,M+NP处理为940.85μg/g,M处理为776.90μg/g,分别比CK增加1.86倍、1.51倍和1.07倍,单施N肥处理对土壤生物活性有机碳库影响不大,为399.10μg/g,仅比CK增加6.4%,NP配合处理为621.60μg/g,比CK增加65.76%。增施有机肥料可明显增大土壤生物活性有机碳库(C0),NP化肥配合施用也有良好效果,N肥单施无明显作用。土壤生物活性有机碳库(C0)占土壤总有机碳(TOC)的百分比为2.70%～6.34%,生物活性有机碳库的周转速率(K)为0.0223～0.0301d-1,生物活性有机碳库在土壤中的半周转期(T1/2)为22.55～31.09d。土壤生物活性有机碳库(C0)与土壤全氮呈极显著性正相关,与总有机碳(TOC)呈显著性正相关。

Effects of Long-term Fertilization on Soil Biologically Active Organic Carbon Pool

The effects of twenty-five years fertilization on soil biologically active organic carbon pool(C_0) have been studied in Pinliang, Gansu. The results showed that active organic carbon pools were significantly increased under organic fertilization treatments,in which active organic carbon pooll(C_0) was 1071.00,940.85, 776.90 μg/g under the mixed application of manure, nitrogen and phosphorus, under the mixed application of straw, nitrogen and phosphorus and under manure, respectively, which was 1.86, 1.51 amd 1.07 time than that with the control that was 375.00 μg/g. There was no significant effect on soil biologically active organic carbon pool under the single application of nitrogen, which only increased by 6.4%, compared to the control. The active organic carbon pool with mixed application of nitrogen and phosphorus was 621.60μg/g,which increased by 65.76% compared to the control. Therefore, soil organic carbon pool can be obviously improved by increasing application of organic fertilization can increase. The mixed application of nitrogen and phosphorus also has good effect on soil organic carbon pool, but it was no obviously effect under the single application of nitrogen. Biologically active soil organic carbon pool (C_0) account total soil organic carbon (TOC) for 2.70%~6.34%. The turnover rate(K) is 0.0223~0.0301 d~(-1) ,and the semi-turnover period of C0 is 22.55~31.09 d. The C0 has highly significant positive correlation with total N, and has significant positive correlation with TOC.