包膜尿素对玉米和小麦的生物学与环境效应

应用渗滤池研究了褐潮土不同用量包膜尿素(POCU)和普通尿素对小麦玉米轮作条件下作物生长发育和地下水污染的影响。结果表明,施用包膜尿素可以显著提高玉米的产量、吸氮量和氮肥利用率;小麦收获期土壤残留氮也明显高于普通尿素处理。玉米的氮肥利用率(55%～140%)明显高于小麦(29.96%4～5.26%)。在每季作物施尿素和包膜尿素N.1002～25.kg/hm2的条件下,地下水淋溶损失的硝态氮量只占施肥量的0.43%1～.12%,表明在目前施肥水平下,中国北方实行的小麦玉米轮作制,一般不存在化肥氮素的淋溶损失。

Biological and environmental effect of coated urea on maize and wheat

A 1-year Lysimeter experiment was conducted to study the effect of different N-release rates of polyolefin-coated urea(POCU) and common urea(U) at different application rates on development of wheat and maize and N losses in a wheat-maize rotation at Changping,Beijing.The results showed that N uptake,N use efficiency and maize yield were higher at POCU plots than at U plots during maize seasons.The residual N in soil with POCU after wheat harvest was higher than that of U.The N use efficiency for maize was higher than that for wheat.N application rates between 100 kg/ha and 225 kg/ha per crop did not significantly affect inorganic nitrogen leaching losses.The total amount of leached inorganic N accounted for 0.43%1.12% of N applied(nitrate accounted for 98% of the leached N).These results indicate that leaching was not the major path of N losses under the environmental conditions of the test site.