论文部分内容阅读
采用长期淹水密闭培养-间歇淋洗法(30℃),测定了长期(16年)定位的水田、旱地和林地土壤有机氮素的矿化氮数量,利用一级反应动力学模型对有机氮素的矿化过程进行了拟合,并探讨了不同利用方式下土壤有机氮素的矿化特征。结果表明,3种利用方式下土壤有机氮素的矿化过程均可用一级反应动力学模型很好地拟合;任意两种土壤利用方式之间的N0值差异均达1%显著水平,水田与旱地、林地之间的k值差异均达1%显著水平,而旱地与林地之间的k值差异则达5%显著水平,林地土壤氮素矿化势最大(72.96 mg kg-1),约为旱地和水田土壤的1.3倍和7.4倍,水田土壤氮素矿化速率最大(0.0908 d-1),约为旱地和林地土壤的4.1倍和2.3倍;旱地和林地土壤供氮能力大小相接近,分别为88.24 mg kg-1和89.11 mg kg-1,约为水田土壤的2倍左右。由此可见,长期(16年)不同利用方式对土壤有机氮素矿化特征影响显著,水田土壤可供矿化的有机氮数量最少且矿化时间最为短暂,旱地土壤可供矿化的有机氮数量较多且矿化时间最为缓慢持久,林地土壤可供矿化的有机氮数量最多且矿化时间较为缓慢持久。
Long-term flooding closed culture-intermittent leaching method (30 ℃) was used to determine the amount of mineralized nitrogen in soil organic nitrogen in paddy field, dry land and forest land with long-term (16 years) location. The first- The mineralization process of mineralization was fitted and the mineralization characteristics of soil organic nitrogen under different utilization modes were discussed. The results showed that the mineralization process of soil organic nitrogen could be fitted well by the first-order reaction kinetics model under three kinds of utilization patterns. The difference of N0 between any two kinds of soil utilization reached 1% significant level. The paddy fields And the k value of dry land and woodland both reached 1% significant level, while the difference of k value between dry land and woodland reached 5%, and the nitrogen mineralization potential of forest land was the highest (72.96 mg kg-1) About 1.3 times and 7.4 times that of dryland and paddy soil respectively. The rate of nitrogen mineralization in paddy soil was the highest (0.0908 d-1), which was 4.1 times and 2.3 times that of dryland and woodland soil respectively. Close to 88.24 mg kg-1 and 89.11 mg kg-1, respectively, about 2 times that of paddy soil. Thus, different long-term (16 years) use patterns have a significant impact on soil organic N mineralization characteristics. The available organic N in paddy soil is the lowest and the mineralization time is shortest. The available organic nitrogen A large number of mineralization time and the most slow and lasting, forest soil mineralization available for the largest number of organic nitrogen and mineralization time is relatively slow and lasting.