湖南双季稻氮磷钾配方优化及追肥运筹增产效果分析

为了筛选出适合湖南双季稻生产的配方复合肥及追肥模式，采用田间试验的方法，在湖南长沙县开慧镇、干杉镇，岳阳县麻塘镇（晚稻在新墙镇）典型双季稻区开展了水稻氮磷钾肥料配方及2次追肥的增产效果研究。结果表明：与主推的配方肥（早、晚稻N-P₂O₅-K₂O分别为20-10-10和26-10-13）相比，优化配方肥（分别增加磷钾比例）适当减氮，早稻保持平产，晚稻增产187.5~378.0 kg/hm²，增产幅度为2.6%~5.9%。其中，N-P₂O₅-K₂O为18-14-16配方适合早稻的生产，N-P₂O₅-K₂O为18-9-16配方适合晚稻的生产。在追肥量一定的条件下，分蘖期、孕穗期分次追肥较分蘖期一次追肥早稻增产187.5~382.5 kg/hm²，氮肥利用率提高10.9~24.2个百分点；晚稻增产258.0~415.5 kg/hm²，氮肥利用率提高8.3~13.4个百分点。

Analysis of Optimized NPK Formulation and Top-dressing on Increasing Yield in Double Cropping Rice of Hunan

The effect of different formula of NPK and top dressed twice on rice growth in typical double cropping rice area, which located at Kaihui, Ganshan, Matang and Xinqiang Town, were studied on field experiment in order to select the formula of compound fertilizer and top dressing mode for double cropping of rice production in Hunan. The results showed that, the rice yields for the optimized formulated fertilizer treatment, which increased the proportion of phosphorus and potassium and reduced its nitrogen fertilizer by 7.5 kg/hm², could ensure early rice stable yield and increased late rice yield by 187.5-378.0 kg/hm² compared with the conventional complex fertilizer (N-P₂O₅-K₂O formula as 20-10-10 for early rice and 26-10-13 for late rice). The N-P₂O₅-K₂O formula 18-14-16 of optimized formulated fertilizer was suitable for early rice production, and the other N-P₂O₅-K₂O formula 18-9-16 was suitable for late rice production. The rice yields for top-dressing at tillering stage, booting stage increased by 187.5-382.5 kg/hm² and 258.0-415.5 kg/hm² for early and late rice, and the nitrogen use efficiency increased 10.9-24.2 percentage points (31.5%-51.1%) for early rice and 8.3-13.4 percentage points (36.2%-64.9%) for late rice compared with the top-dressing at tillering stage.