辽河平原地区长期施肥水稻土氮素矿化及其模拟的研究

Nitrogen Mineralization and Simulation of Paddy Soil under Different Long-term Fertilization in Liaohe Plain Region

采用长期淹水密闭——间歇淋洗培养方法和分析手段,研究了辽河平原地区连续16年长期不同施肥(不施氮肥、氮肥、氮肥+有机肥、氮肥+有机肥+放萍)水稻土氮素的矿化过程。结果表明长期不同施肥水稻土氮矿化量为N15.61～103.57mgkg-1,为全N的1.25%～5.66%;氮肥+有机肥处理土壤氮矿化量最高,占全氮比率最大,而氮肥处理土壤氮矿化量最低,占全氮的比率最小;氮矿化量与全氮、有机质、C/N之间呈显著相关关系(P<0.05)。选择有效积温式(EATM);一级反应式(One-pool模型);带常数项的一级反应式(Special模型),对实验数据进行拟合。非线性拟合结果表明Special模型明显优于One-pool模型和有效积温式(EATM)。分析表明Special模型能更为准确地描述长期不同施肥措施下水稻土有机氮素的矿化。

Based on a 16-year long-term fe fertilizer ＋ Organic fertilizer, Nitrogen fertilizer rtilizing practices （No nitrogen fertilizer, Nitrogen fertilizer, Nitrogen ＋ Organic fertilizer ＋Azolla ）in paddy soil in Shenyang, Liaohe plain region, the effect of long-term fertilizing practices on nitrogen mineralization of paddy soil was studied used long-term （126 days） flooding-intermittent leaching cultivation. Results showed the nitrogen mineralization amount of paddy soil was among 15.61 - 103.57mg kg^-1, which was 1.25% - 5.66% of total N. The treatment of nitrogen fertilizer ＋ Organic fertilizer resulted in the biggest nitrogen mineralization amount and accounted for the main part of total N. The treatment of Nitrogen fertilizer resulted in the least nitrogen mineralization amount and accounted for the minimum of total N. There were significantly correlation between nitrogen mineralization amount and total N, organic matter and C/N（p〈0.05）. The fit of experiment data was proceeded choose effective accumulated temperature model （EATM）, first order exponential model （one-pool model） and mixed first and zero order exponential model including a constant term （Special model）. The results of nonlinear fitting showed that special model was distinctly superior to One-pool model and EATM and it could describe clearly nitrogen mineralization of paddy soil under different long-term fertilizing practices.