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本文应用~(15)N示踪法,测定并探讨了土壤中三种水分状况及四种不同C/N值肥料对肥料氮素转化的影响,试验结果表明:土壤水分和肥料C/N值均对水稻产量有较大的影响,相比之下,土壤水分的影响似更大。水稻对肥料氮的吸收利用率,淹水栽植高于旱植,氮素固定在旱地条件下作用加强,淹水并有一定渗漏的土壤上肥料氮的损失最大,示踪结果说明从土壤渗漏液中淋失的氮素80%以上为土壤固有氮素,相对而言肥料氮的损失较低。试验还表明肥料中碳氮值与肥料氮的吸收利用率之间呈负相关,与肥料残留率呈正相关。此外,本试验还测定了土壤水湿状况和肥料碳氮值在土壤氮素转化中的作用,讨论了当土壤氮素矿化和固定作用相等时,有机肥的碳氮临界值及其实用意义。
In this paper, the effects of three water conditions and four different C / N fertilizers on nitrogen transformation of fertilizer were determined and discussed by ~ (15) N tracer method. The results showed that soil moisture and fertilizer C / N ratio Both have a greater impact on rice yield, in contrast, soil moisture seems to be more influential. The uptake and utilization rate of nitrogen by fertilizers in rice was higher than that in dry land, and the effect of nitrogen fixation in dry land was stronger. The loss of fertilizer nitrogen in the flooded and some leaking soil was the largest. Leakage leaching of nitrogen more than 80% of the soil intrinsic nitrogen, nitrogen fertilizer relatively low loss. The experiment also showed that there was a negative correlation between the carbon and nitrogen of fertilizers and the nitrogen uptake and utilization rate of fertilizer, which was positively correlated with the residual rate of fertilizer. In addition, the experiment also measured the effect of soil moisture status and fertilizer carbon and nitrogen value on soil nitrogen transformation, and discussed the critical value of organic carbon and nitrogen and its practical significance when soil nitrogen mineralization and fixation are equal .