长期不同施肥处理对棕壤氮储量的影响

Effect of long-term fertilization on total nitrogen storage in a brown soil

为揭示施肥对棕壤氮素状况的影响,利用29年长期肥料定位试验,研究了不同施肥处理条件下土壤全氮在0—60 cm土层的分布特征,并在此基础上计算0—60 cm土层氮库的储量变化。结果表明,不同施肥处理土壤全氮含量、C/N比值均随土层深度增加而降低,其影响主要表现在表层;而对0—60 cm土层全氮储量有显著影响(P<0.05)。长期不同施肥处理后土壤全氮及其储量变化趋势为:高量有机肥区>低量有机肥区>化肥区>无肥区>试验前(1979年),特别是高量有机肥和化肥配合施用效果最显著;单施化肥处理土壤全氮含量和储量虽有缓慢提高,但差异不显著。说明土壤氮素含量的提高与施肥措施密切相关,有机肥和化肥配合施用能提高土壤全氮含量和储量,是维持土壤肥力的最优施肥方式。

Soil nitrogen （N） is an important indicator of soil fertility, which is affected by natural factors and fertilization practices. The changes of N in 0-60 cm layer of a brown soil in a long-term fertilizer location experiment （29 years） were studied. Results showed that soil total nitrogen （TN） and the C/N ratio significantly declined with depth. Different fertilizer treatments not only significantly affected TN contents and the C/N ratio in the topsoils, but also the soil total nitrogen storage in 0-60 cm soil layer. The storage of soil total N followed the order： high level of organic manure treatment 〉 low level of organic manure treatment 〉 fertilizer treatment 〉 check treatment 〉 the formal soil （1979）. Combine application inorganic fertilizers and high level of organic manure had the most significant impact on TN and the soil nitrogen storage. Although single application inorganic fertilizer could enhance the concentration, but less significance compared to combine application with organic fertilizer, indicating the changes of soil total nitrogen content closely related to the different fertilization. Manure plus mineral fertilizer increased the content of TN and TN storage, and was considered the best way for maintaining the soil fertility and sustainable agriculture.