包膜尿素对旱地红壤氮素垂直迁移特征的影响

Effects of Resin Coated Urea on Nitrogen Vertical Migration in Red Soil Dryland

结合花生田间试验，利用原位土壤溶液取样装置，研究了一次性基施包膜尿素对典型红壤旱地0—100cm深度土壤溶液氮（N）素垂直迁移特征的影响。结果表明，①早地0—100cm土层红壤溶液N素含量以NO3--N含量最高，且以包膜肥料处理较明显；②对照处理0～100cm土层红壤N素含量变化不大，而普通尿素和包膜尿素处理0～60cm上层的N素变化较大，尤以花生花期最明显；③包膜尿素能较长时问维持耕层（0～40cm）土壤溶液较高的N素含量，减少N素向红壤较深层（60cm）迁移。④红壤旱地上一次性基施N150kg／hm2的包膜尿素种植花生，包膜尿素养分的释放与花生对N营养的吸收相配性较差，仍待进一步调整施肥量。

Based on an in situ peanut field experiment, the vertical migration of solution nitrogen in red soil dryland was studied under the application of resin coated urea as a basic fertilizer. The results showed that at 0-100cm depth, the concentration of NO3-N was the highest in various N-forms, particularly in the treatment of resin coated urea applied （BN treatment）. The variation of nitrogen concentration at 0-100 cm was smaller under CK treatment （no nitrogen fertilizer used）, but were greater at 0-60 cm under BN treatment and PN treatment （routine urea applied）, especially at the florescence stage. Compared with FN treatment, BN treatment kept a higher nitrogen supply capacity for a longer time at cultivated horizon （0-40cm） and reduced nitrogen downward migration. However, when resin coated urea was applied as base fertilizer with an amount of N 150 kg/hm2 in red soil dryland, a weak-assorted relation occurred between nitrogen release of resin coated urea and nitrogen absorption of peanut, thus the application amount of resin coated urea still needs to be adjusted.