NEEM (Azadirachta indica) OIL COATED UREA IMPROVES NITROGEN USE EFFICIENCY AND MAIZE GROWTH IN AN ALKALINE CALCAREOUS SOIL
NEEM (Azadirachta indica) OIL COATED UREA IMPROVES NITROGEN USE EFFICIENCY AND MAIZE GROWTH IN AN ALKALINE CALCAREOUS SOIL
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DOI：
10.21162/pakjas/20.9850
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发表时间：
2020-06-01
影响因子：
0.8
通讯作者：
Awan, Masood Iqbal
中科院分区：
文献类型：
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作者：
Ali, Mohsin;Maqsood, Muhammad Aamer;Awan, Masood Iqbal
为了评价印楝油包膜尿素（NOCU）作为天然硝化抑制剂和提高玉米氮素利用效率，进行了两个独立的试验。在第一个实验中，用递增水平（即1%、2%和3%w/v）的印楝油涂层进行土壤培养28天，以监测NH 4+和NO3-含量的释放。印楝油包膜尿素减缓了无机氮的释放，与2%和1%相比，印楝油包膜尿素在3%水平下具有最大的硝化抑制（40%），因此被选择用于下一个研究。在随后的盆栽试验中，NOCU按照推荐剂量（250 kg ha（-1））以三种不同水平（50%、75%和100%）施用于玉米作物。地上部和籽粒中的氮含量显著增加，最终引起玉米籽粒中蛋白质含量的增加。施用NOCU可提高氮素的有效性，延长氮素的利用时间，从而促进氮素的吸收，提高籽粒产量。NOCU用量为75%时，氮肥的农学效率最高（24.38 g g（-1）），而NOCU用量为100%时，氮肥的利用率最高（0.44 g g（-1））。总之，施用NOCU比普通尿素节省25%的氮肥。
Two independent experiments were conducted to assess neem oil coated urea (NOCU), as a natural nitrification inhibitor and to improve nitrogen use efficiency in maize. In first experiment, soil incubation with increasing levels (i.e. 1%, 2% and 3% w/v) of neem oil coating was done for 28 days to monitor the release of NH4+ and NO3- contents. Neem oil coated urea slowed down the release of mineral N with maximum nitrification inhibition (40%) at 3% level of neem coating as compared to 2% and 1%, hence selected for next study. In the subsequent pot study, NOCU was applied according to recommended dose (250 kg ha(-1)) of urea at three different levels (50%, 75% and 100%) for maize crop. There was a significant increase in N contents of shoot and grains that ultimately provoked high protein contents in maize grains. Application of NOCU enhanced the N uptake due to its increased availability for longer period of time, resulting in higher grain yield. Maximum agronomic efficiency (24.38 g g(-1)) of applied N was observed with 75% dose of NOCU, while maximum recovery efficiency (0.44 g g(-1)) was recorded with 100% dose of NOCU. Conclusively, application of NOCU saves 25% N application compared to ordinary urea.