树脂膜控释尿素对小白菜生长的影响

目的]为控释肥的研制和应用提供理论和实践依据。方法]以普通尿素为对照，通过对比试验研究了不同控释尿素对小白菜生长的影响。结果]4月8日，树脂膜控释尿素处理的叶绿素测定值比普通尿素处理低0．6％～7．3％；5月8日和28日，其叶绿素测定值分别比普通尿素处理高10．8％～21．8％和26．1％～35．9％。收获期测定的树脂膜控释尿素处理的根系活力为普通尿素处理的1．2～1．4倍。与空白处理相比，普通尿素处理的增产幅度为11．6％，树脂膜控释尿素处理的小白菜的氮、磷、钾平均含量分别增加了35．6％、55．9％和90．5％。与普通尿素处理相比，树脂膜控释尿素处理的平均增产幅度为28．3％，其氮、磷、钾平均含量分别增加了32．7％、22．4％和46．5％，其硝酸盐含量平均降低了31．4％，其Vc含量平均升高了53．1％。结论]6％树脂膜控释尿素的释放规律与释放期与小白菜的养分吸收规律和生育期拟合最佳。

Influences of Controlled-release Urea Coated by Resin Film on the Growth of Pakchoi

Objective] The research aimed to provide theoretical and practical basis for preparing and applying controlled-release fertilizers.Method] With common urea as CK,the influences of different controlled-release urea on the growth of pakchoi were researched through comparative experiment.Result] On Apr.8th,the spad value in the treatment with controlled-release urea coated by resin film was 0.6%-7.3% lower than that in the treatment with common urea;on May 8th and 28th,its spad values were 10.8%-21.8% and 26.1%-35.9% higher than that in the treatment with common urea resp.The root vitality detected in harvest stage in the treatment with controlled-release urea coated by resin film was 1.2-1.4 times of that in the treatment with common urea.Compared with blank treatment,the yield of pakchoi treated with common urea was increased by 11.6% and the average contents of nitrogen,phosphorous and potassium in the pakchoi treated with controlled-release urea coated by resin film were increased by 35.6%,55.9% and 90.5% resp.Compared with the treatment with common urea,the average yield of pakchoi treated with controlled-release urea coated by resin film was increased by 28.3%,its average contents of nitrogen,phosphorous and potassium were increased by 32.7%,22.4% and 46.5% resp.,its average content of nitrate was reduced by 31.4% and its average content of Vc was increased by 53.1%.Conclusion] The release law and release period of controlled-release urea coated by 6% resin film were best fit with the nutrient absorption law and growth period of pakchoi.