缓释尿素不同用量对土壤氮素变化状况的影响

Effects of Different Slow-release Urea Rates on Soil Nitrogen

通过田间试验,研究了缓释尿素用量与土壤氮素的变化情况。结果表明,缓释尿素对土壤全氮的含量没有影响,能够增加土壤碱解氮的含量,但是不同层次增加的幅度不同,由表层向下依次增加,说明缓释尿素容易随水向下土层迁移。土壤碱解氮的含量萌芽前至开花期明显增加,开花期到坐果期基本稳定不变,说明由于缓释尿素的缓释作用,在不追肥的情况下,能够使土壤碱解氮在坐果期仍能保持较高的水平。

The field experiment was conducted to study the relationship between application rates of slow - release urea and soil nitrogen variation. The results showed that the slow - release urea did not affect the to- tal nitrogen content in soil, but the content of soil alkali - hydro nitrogen was increased with the deepening of soil layers, which indicated that slow- release urea could shift easily downward soil layers along with water. The alkali -hydro nitrogen content in soil increased significantly from pregerminating to flowering period, and was basically stable from the flowering period to fruit - setting period, which indicated that the alkali - hydro nitrogen could maintain a high level in the fruit - setting period without topdressing because of the slow release effect.