不同施肥措施对潮土有机碳平衡及固碳潜力的影响

以中国科学院封丘农业生态实验站的长期定位施肥试验为研究平台,研究不同施肥措施对潮土有机C含量的影响,并利用Jenny模型对不同施肥措施下的潮土有机C动态进行模拟。结果表明,施肥措施明显改变了潮土有机C含量,并且有机肥处理的作用效果要明显优于化肥处理。不同施肥措施不仅改变了潮土有机C的平衡水平,也影响了有机C的分解速率,NPK、1/2OM和OM施肥处理的有机C平衡值分别为7.19、7.75和9.37g/kg,而分解速率分别为0.038、0.113和0.1451/a。在目前施肥模式不变的情况下,与试验初相比,达到平衡时CK处理的潮土将会损失C1478kg/hm2,而NPK、1/2OM和OM处理的潮土则会分别增加C7376、7790和12066kg/hm2。因此,可以认为施肥处理促进了潮土的C固定。

Effect of Fertilization on Equilibrium Levels of Organic Carbon and Capacities of Soil Stabilizing Organic Carbon for Fluvo-aquic Soil

Long-term experiment in Fluvo-aquic soil at Fengqiu Agro-Ecological Experiment Station of CAS in Henan was utilized to study effect of different fertilization treatments on soil organic carbon (SOC), and simple Jenny model was used to simulate dynamics of organic carbon. Results showed that application of inorganic and organic fertilizers significantly increased SOC contents of Fluvo-aquic soil, while effect of organic fertilizer was more obvious than inorganic fertilizer; Fertilization not only affected equilibrium levels of organic carbon but also changed decomposition rates of organic carbon significantly; Eequilibrium values of organic carbon were 7.19, 7.75 and 9.37 g/kg for NPK, 1/2OM and OM treatments, respectively whereas the decomposition rates of organic carbon were 0.038, 0.113 and 0.145 1/a for corresponding three fertilizer treatments, respectively. Compared with storage of C in 1989, when soil organic carbon reached the equilibrium state, storage of C in CK treatment would lose 1478 kg/hm2, but would increase 7376, 7790 and 12066 kg/hm2 in NPK, 1/2OM and OM treatments, respectively; Fertilization practices would intensify Fluvo-aquic soil function as C sink.