| 摘要: |
| 采用电导法和好气培养连续取样法探讨包膜控释尿素保肥供肥效果及其机理，探讨评价包膜控释供肥速度的方法。结果表明，在恒温条件下培养42 d，包膜型控释尿素在土壤中确有控制养分释放、延长供氮时间的作用，与对照相比供氮时间可延长30 d以上，即将尿素包膜制成控释肥料，可以明显抑制尿素的水解，从而起到保肥的效果。试验结束时，土壤残留肥料中的含氮量为肥料含氮总量的21％。结果还证明，用电导法和土壤培养法得到的控释尿素的供氮曲线具有一致的变化规律，故可以用电导法简单、快速测定控释肥料的供氮速度，评价包膜控释肥的肥效， |
| 关键词: 包膜型控释尿素 供氮量 保肥供肥效果 电导法 |
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| 基金项目:国家自然科学基金资助项目(39870433);广东省自然科学基金资助项目(98036);教委骨干教师计划项目(2000-65-34);广东省科技攻关项目(2KB05601N) |
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| Study on efficiency and mechanism of N supply and preservation of controlled release coated urea |
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| Abstract: |
| Ventilating incubation method was used to investigate the efficiency and mechanism of Nsupply and its efficiency of controlled release coated urea (CRFUC) by successive collection of fertilizer samples after a period of incubation and analyzing EC of CRFCU as well as mineral nitrogen of soil extracts.The results indicated that the period of nitrogen release of the coated urea was 30 days longer than that of CK under the constant temperature (25 ℃) during 42 days incubation.It revealed that converting normal urea into coated compounds (coated urea) could reduce hydrolysis of urea and then keep more N in the soil.The result also showed that the remaining nitrogen fertilizer in soil was about 21% of total nitrogen at the end of the incubation.The curve of nitrogen supply was similar to those of incubation method and EC method.As a result,it was possible use EC method to evaluate N supply of the coated urea simply and rapidly insead of time consumption incubation method. |
| Key words: coated urea quantity of nitrogen supply N preservation and supply EC method |
