【摘要】 本文报告了尿素粒肥在石灰性砂壤土上对夏玉米的效应及其氮素去向。在石灰性砂壤土上尿素粉肥条撒(雨前施肥或结合灌溉)可以起到尿素深施的作用。在供试土壤上施用尿素,肥料氮的淋洗程度是重2.17克的粒肥深施>重1.09克的粒肥深施>粉肥深施>粉肥条撒。但玉米地上部分吸收肥料氮的情况正好与肥料氮在土壤中的淋洗难易趋势相反。收获时玉米地上部分吸收利用了48.5%的肥料氮量,0—80厘米微区土壤中残留了17.6%,而氮肥损失(亏缺)为33.9%。更多还原

【Abstract】 Present article deals with the effect of granulated urea in different sizes （powder, 1.09 and 2.17g per granule） on the yield of corn grown on calcareous sandy soil derived from loessial deposits in Fenqiu County of Henan Province. Field experiments were conducted on plots of 14.0m×2.4m in 5 treatments （deep placement of granules of 2 sizes and powder, broadcasting of powder and control）, and on microplots which were laid in each plot separated by a bottomless square cylinder （50cm×40cm×40cm）. ¹⁵N-labelled urea was applied in microplots. In all the treatments, irrigation was carried on immediately after applying the fertilizer. Results obtained showed that top dressing powdered urea in band followed by irrigation or before raining gave similar grain yield of corn to the deep application of either powdered or granulated urea on the soil. The leaching rates of urea in different treatments were in a descending order of deep application of granule of 2.17g>deep application of granule of 1.09g >deep application of powder>broadcasting of powder. However, the amounts of fertilizer-N absorbed by corn plant tended to the opposite order. At repening stage, 48.5% of the fertilizer-N was absorbed by corn plant, 17.6% was retained in soil layer of 0-80cm, and 33.9% was the deficit.更多还原