Grain yield and apparent N recovery efficiency of dry direct-seeded rice under different N treatments aimed to reduce soil ammonia volatilization

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• 作者：Xiaoli Qi ; Lixiao Nie ; Hongyan Liu ; Shaobing Peng ; Farooq Shah ; Jianliang Huang ; Kehui Cui ; Liming Sun
• 关键词：Ammonia volatilization ; Apparent N recovery efficiency ; Dry direct-seeded rice ; Grain yield ; N management practice
• 刊名：Field Crops Research
• 出版年：2012
• 出版时间：12 August, 2012
• 年：2012
• 卷：134
• 期：Complete
• 页码：138-143
• 全文大小：275 K

文摘

Soil ammonia volatilization induced by urea application at sowing negatively affects seed germination and early seedling growth of dry direct-seeded rice. Previous research suggests that ammonia volatilization can be reduced through nitrogen (N) management practices such as split application of urea, delaying the first urea application, and using N fertilizers which are less prone to volatilization. The objective of this study was to examine the impact of these N management practices on grain yield and nitrogen use efficiency of dry direct-seeded rice. Pot and field experiments were conducted under different N treatments. In the pot experiment, N treatments were 1.0 and 0.5 g N pot^?1 as urea at sowing, 1.0 g N pot^?1 as urea at 10 days after sowing (DAS), and 1.0 g N pot^?1 as ammonium sulfate at sowing. In the field experiment five N treatments were used while keeping the total N rate as 150 kg N ha^?1. These treatments included reducing the rates of urea applied at sowing from 90 to 60 and 30 kg N ha^?1, delaying the first urea application to 10 DAS at 90 kg N ha^?1, and application of ammonium sulfate as 90 kg N ha^?1 at sowing. Reducing rate of urea applied at sowing, delaying the first urea application, or application of ammonium sulfate significantly increased plant growth, grain yield, above-ground N uptake and apparent N recovery (ANR) efficiency of dry direct-seeded rice, compared with higher rate of urea application at sowing. Here we demonstrate that by adoption of proper N management practices, a grain yield of above 6 t ha^?1 can be achieved in dry direct-seeded rice production system. Such findings may greatly help in the wide spread of dry direct-seeded rice technology, particularly in central China.