| 控释肥条件下沿南四湖农田水稻吸氮特征 |
| 摘要点击 2596 全文点击 2234 投稿时间：2010-08-05 修订日期：2010-09-14 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 南四湖流域 水稻 吸氮速率 氮肥利用率 控释氮肥 |
| 英文关键词 Nansi Lake basin rice N uptake rate N use efficiency controlled-release fertilizer |
|
| 中文摘要 |
| 氮素是水稻必需营养元素中限制植物生长和形成产量的首要因素，同时也是南四湖水体主要营养性污染物之一.通过施用树脂包膜控释尿素不同氮肥量处理大田试验，研究了南四湖流域鱼台农田控释肥条件下水稻生育期的吸氮特征.结果表明，树脂包膜控释尿素对水稻产量有明显的促进作用，但并不随施氮量的增加呈线性增长，施用中氮量337.5 kg/hm2水平下吸氮速率和氮肥利用率最高，吸氮速率为22.48 mg/(株·d），氮肥利用率为37.17%，均显著高于低氮和高氮的处理.控释尿素对生物学特性的影响有明显的阶段性，水稻吸氮高峰出现在幼穗分化期.随着施肥水平的提高，水稻体内每积累1 kg氮素而增加的产量呈下降趋势.以南四湖流域济宁市年施氮肥量16.65×104 t为基数，如果施用包膜控释尿素337.5 kg/hm2，济宁市年均损失氮肥10.46×104 t，可年均减少损失2.55×104 t，仅鱼台县可年均减少损失2235.26 t.高量的氮肥投入引起过剩的氮素流失成为潜在的面源污染源，根据水稻生育期需肥规律确定控释肥最佳施用量，是保持水稻稳产的前提下减少因超量施肥导致氮素流入水体的关键途径. |
| 英文摘要 |
| The nitrogen(N) fertilizers overused or misused are the main contributors for water eutrophication of the Nansi Lake in eastern China. A field experiment with different application levels of controlled-release N fertilizer (CRF) was carried out at a rice field in the Nansi lake basin to provide information on the nitrogen uptake rate and use efficiency by rice with CRF application at different growth stages of rice. The fertilization levels for the controlled fertilizer in this study were 0, 300, 337.5 and 375 kg/hm2, respectively, and 375 kg/hm2 for conventional urea(CU). We estimated the N uptake rate in different growing season and apparent recovery of fertilizer in root, stover and grain of rice. The result showed that grain yield increased by higher N rate. However, the N uptake rate did not increase linearly with the nitrogen application amount. The highest N uptake rate was 22.48 mg/（plant·d） under the fertilization amount of 337.5 kg/hm2 during the young panicle differentiation stage. Apparent N recovery efficiency for CU with traditional application amount of 375 kg/hm2 was 21.86%. Apparent N recovery efficiency for CRF with application amount of 337.5 kg/hm2was highest with 37.17%. Based on the statistical data, with CU of traditional urea application amount of 375 kg/hm2，nitrogen loss and soil N residue at one growing season are 130.07×103 t for Jining city and 11.4×103 t for Yutai county of the Nansi Lake basin. If using CRF with the optimized application amount of 337.5 kg/hm2, nitrogen loss and soil residual at one growing season is 10.46×104 t for Jining city. It could reduce losses of 2.55×104 t N for Jining city and 2235.26 t N for Yutai county per year. Because of releasing patterns more closely matched to crop N uptake patterns, controlled release N fertilizer could be a good way to prevent water eutrophication due to nitrogen fertilizer overused or misused in the Nansi Lake. |
