长期施肥对栗褐土活性有机碳的影响

Effect of long-term fertilization on labile organic carbon in cinnamon soil

以25年长期定位施肥试验为依托,研究了不同施肥处理对栗褐土活性有机碳及碳库管理指数的影响。结果表明,长期施用不同肥料不同程度地提高了栗褐土水溶性碳、轻组有机碳的含量,其中,有机肥与氮磷肥配施(M1NP、M2NP)水溶性有机碳含量增加明显,较对照分别增加了93%和99%,高量有机肥与化肥配施(M2N、M2NP)对轻组有机碳含量的影响大,分别比对照高240%和360%。单施化肥和单施有机肥土壤易氧化有机碳含量无显著变化,而有机肥与化肥配施则显著提高。单施有机肥土壤水溶性有机碳所占比例呈上升趋势,其他处理则有所下降。单施氮肥轻组有机碳的分配比例明显降低,高量有机肥与化肥配施则明显提高。单施化肥易氧化有机碳所占比例显著下降。单施化肥栗褐土碳库管理指数有下降趋势,单施有机肥及有机肥与化肥配施有利于提高碳库管理指数,高量有机肥与化肥配合施用的效果更佳,比对照分别高145%和180%。相关分析表明,长期施肥条件下栗褐土水溶性、轻组、易氧化有机碳含量之间及其与总有机碳含量之间均呈显著或极显著正相关。

Based on a 25-year long-term fertilization experiment, the effects of different fertilizing treatments on labile organic carbon and carbon pool management index in cinnamon soil were analyzed. The results showed that compared with no fertilizer application （CK）, the treatments of different fertilizer applications increased the contents of WSOC and LFOC in cinnamon soil. The contents of WSOC in the treatments of manure combined with chemical nitrogen and phosphorus fertilizer applications （M1NP, M2NP） were 93% and 99% higher than that of CK, respectively. The effect of higherrate manure applications with chemical fertilizer （M2N, M2NP） on LFOC were more significant, increasing the content of LFOC by 240% and 360% compared to CK, respectively. After longterm application of single chemical and manure fertilizer, the content of EOC kept no significant change, while it increased significantly under the treatment of applying manure combined with chemical fertilizer. The distribution proportion of WSOC increased under the application of single manure fertilizer but decreased in the other treatments. Compared with CK, the proportion of LFOC in SOC decreased significantly under the single nitrogen fertilization but increased significantly under higherrate manure application chemical fertilizer. The distribution proportion of EOC decreased under single chemical fertilizer application. Single chemical fertilizer application had a lower soil organic carbon pool management index （CPMI） compared with CK. Longterm application of manure alone or combined with chemical fertilizer were effective measures to promote CPMI. In these treatments, M2N and M2NP had the most significant effect, and the CPMI increased by 145% and 180% compared with CK, respectively. The correlation analysis indicated that under the longterm fertilization application, the contents of WSOC, LFOC and EOC were significantly positively correlated to each other, and had a strong positive correlation with the total organic carbon content.