水稻小麦种植模式下长期定位施肥土壤氮的垂直变化及氮储量

为了研究不同的施肥方式对土壤全氮变化及氮储量的影响,1981年在湖北省农业科学院南湖试验站设置了施用有机肥与化肥的长期定位田间试验,2006年水稻收获后田间取样分析每个处理不同土层的全氮含量与氮储量。研究结果表明：与对照相比,单施化肥与单施有机肥0～20cm土层土壤的容重下降,化肥添加有机肥比相应的单施化肥的容重要低一些。除了对照之外,其它处理都是0～20cm土层土壤全氮含量高于其它土层,氮肥配施有机肥处理0～20cm土层土壤全氮含量最高。除了氮磷钾肥配施过量有机肥处理外,化肥配施有机肥处理土壤的全氮含量都高于单施化肥或单施有机肥处理,20～40cm土层土壤全氮含量具有相似的规律。在0～20cm土层,与对照相比,单施氮肥及氮磷肥不能增加土壤全氮储量,但是化肥配施有机肥能够增加土壤全氮的储量。单施氮磷钾肥及单施有机肥也能够增加土壤全氮的储量。在0～20cm土层,氮肥配施有机肥处理的土壤全氮储量最多,达8.82t·hm-2,而氮肥处理的氮储量最低,仅为5.38t·hm-2。在100cm深度,与单施化肥及单施有机肥相比,化肥配施有机肥都增加了土壤全氮的储量。

Vertical variation and storage of soil total nitrogen in long-term fertilizer experiment

In order to study to effect of different application fertilizer mode on soil total nitrogen concentration and storage, long-term fertilizer experiment were carried out in Nanhu experiment station, Hubei Academy of Agricultural Sciences in 1981. Soil samples were collected from each treatment in 2006 after rice harvested and soil total nitrogen concentration and storage were analyzed. The results show that soil bulk density in 0-20 cm soil layer decreased in single application nitrogen or manure treatment compared to control and decreased in combining application of chemical fertilizer with manure treatment compared to single application of chemical fertilizer. Soil total nitrogen content in 0-20 cm soil layer was higher than in other soil layer under all treatments except control. Soil total nitrogen content in 0-20 cm soil layer was the highest in combining application of nitrogen fertilizer with manure treatment than in the other treatments. The soil total nitrogen content in 0-20 cm soil layer were increased in combining application of chemical fertilizer with manure treatment compared to single application of chemical fertilizer or manure treatment except combining application of nitrogen, phosphate, potassium fertilizer with excess manure treatment and there had similar trend in 20-40 cm soil layer. Soil total nitrogen storage in 0-20 cm soil layer under single application of nitrogen or nitrogen, phosphate fertilizer treatment was low than in control, but was increased in combining application of chemical fertilizer with manure treatment and single application of nitrogen, phosphate, potassium fertilizer or manure than in control. Soil total nitrogen storage in 0-20 cm soil layer under in combining application of nitrogen fertilizer with manure treatment was the highest and reached 8.82 t·hm-2, whereas soil total nitrogen storage in 0-20 cm soil layer under single application of nitrogen fertilizer treatment was the lowest and was 5.38 t·hm-2. The soil total nitrogen storage in 0-100 cm soil layer were increased in combining application of chemical fertilizer with manure treatment compared to single application of chemical fertilizer or manure treatment.