配施有机肥条件下油菜化肥氮减施潜力研究

Effects of applying the same amount of organic fertilizer at different nitrogen application rates on the growth,yield and economic benefits of rapeseed

探明湖南省油菜种植区配施有机肥条件下化肥氮减施潜力,为该地区油菜生产中氮肥减施增效提供参考。田间试验在湖南省郴州市进行,供试油菜品种为湘油420,采用裂区设计,研究配施等量(2250 kg/hm^(2))有机肥条件下不同氮肥用量(0、90、135、180、225、270 kg/hm^(2))对油菜生长、产量、理论产油量和经济效益的影响。结果表明,所有氮肥水平下配施有机肥均显著提高油菜产量,且在低氮水平下增产效果更加明显,有机肥的增产效果主要通过增加单株角果数和每角果粒数来实现。在不施与施有机肥条件下,施氮量分别为213和199 kg/hm^(2)时油菜籽产量最高,分别为1754和2514 kg/hm^(2),氮肥减少了6.6%、产量提高了43.3%;施用有机肥条件下达到不施有机肥的最高产量值仅需127 kg/hm^(2)氮肥,减少了44.1%。所有供氮水平下,施用有机肥可显著增加氮素积累量、理论产油量和经济效益,包括有机肥氮的氮肥偏生产力也呈增加趋势,而包括有机肥氮的氮肥农学效率和氮肥表观利用率变化较小;与不施有机肥相比,施有机肥的最高理论产油量施氮量减少了3.0%,最高效益施氮量减少了20.0%,而理论产油量和效益分别增加了41.1%和50.0%。

The effect of organic fertilizer application under different chemical nitrogen fertilizer managements on rapeseed crop performance was explored to provide reference for reducing chemical nitrogen rate application and increasing nitrogen efficiency in rapeseed production of Hunan province.A field experiment was conducted using a widely grown rapeseed variety Xiangyou420 in Chenzhou county,Hunan province,China.The experiment was arranged in a splitplot design,with six chemical nitrogen application rates(0,90,135,180,225 and 270 kg/hm^(2))as main plots and two organic fertilizer application(0 and 2250 kg/hm^(2))as subplots.The results showed that as compared with treatment without organic fertilizer,applying organic fertilizer significantly increased rapeseed yield in all chemical nitrogen rate treatments,with significantly higher yield increment in lower chemical nitrogen rate.Higher yield in treatment of applying organic fertilizer was mainly due to the higher number of siliques per plant and the number of seeds per siliques than those in treatment without organic fertilizer.The highest rapeseed yield was 2514 and 1754 kg/hm^(2)in treatments with and without organic fertilizer at chemical nitrogen rate of 199 and 213 kg/hm^(2),respectively.The results indicated that applying organic fertilizer increased the highest yield by 43.3%with 6.6%lower chemical nitrogen rate relative to treatment without organic fertilizer.Applying organic fertilizer reduced chemical nitrogen rate by 44.1%to a rate of 127 kg/hm^(2)to achieve the same high-yielding level as compared with treatment without organic fertilizer.Applying organic fertilizer significantly increased crop nitrogen accumulation,theoretical oil production,and economic benefit.Application of organic fertilizer increased partial factor productivity of applied nitrogen from both chemical and organic fertilizers,while it had no impact on agronomic efficiency and apparent use efficiency of applied nitrogen from both chemical and organic fertilizers.As compared with treatment without organic fertilizer,applying organic fertilizer reduced nitrogen application rate by 3.0%and 20.0%for achieving the highest theoretical oil production and economic benefit,respectively,while increased oil production and economic benefit by 41.1%and 50.0%,respectively.