氮肥对甘蓝产量、硝酸盐含量及土壤硝态氮含量的影响

通过田间小区试验为研究不同氮肥用量对北京地区甘蓝产量、品质以及土壤硝态氮含量的影响。试验结果表明:(1)0~60 cm土层中3个采样周期土壤硝态氮含量随氮肥量级增加而升高,并且随着作物的生长,0~30 cm土层中土壤中硝态氮含量呈现下降的趋势,30~60 cm土层中基本呈现上升的趋势;60~90 cm土层中变化较小;(2)随着氮肥投入增加,甘蓝产量呈现先增加后降低的趋势,当氮肥的添加量为240 kg/hm2时产量最高;(3)随着氮肥施用量的升高,甘蓝对氮素的吸收量呈现先上升后下降的趋势,添加氮肥处理的甘蓝对氮素的吸收量均显著高于不添加氮肥处理,并且施用氮肥的处理中甘蓝叶片硝酸盐含量显著高于不施氮肥处理,并且不同供氮水平叶片硝酸盐含量变化各不相同。综合以上试验结果可知,氮肥的添加对0~60 cm土层中硝态氮含量的影响较大,并且适量的氮肥添加量(240 kg/hm2)能够有效提高北京地区甘蓝的产量以及甘蓝对氮素的吸收量等。

Effect of Nitrogen Fertilizer on Yield and NO3--N Content of Brassica oleracea and NO3--N Content of Soil

The effect of yield and quality of brassica oleracea and NO₃-N content of soil with different nitrogen fertilizer level was studied according to the field experiments. The results showed that: (1) The content of NO₃-N in soil was increased with the increase of nitrogen level with three sampling period in 0-60cm soils. Besides, with the growth of the crops, the content of NO₃-N in 0-30cm soils showed the tendency of decline, and the content of NO₃-N in 30-60cm soils increases, and the content of NO₃-N in 60-90 soils had almost no change; (2) The yield of brassica oleracea showed a trend of lower after the first increase with the increasing of nitrogen inputs, and the yield was the highest when the inputs of nitrogen was 240 kg.hm_-2; (3) ) The absorption of nitrogen by brassica oleracea showed a trend of lower after the first increase with the increasing of the nitrogen fertilizer application. Compared with the treatment without nitrogen fertilizer, the treatment with nitrogen fertilizer was higher respectively, and so as the nitrate content in leaves of brassica oleracea. Besides, the nitrate content in leaves of brassica oleracea were different between different levels of nitrogen fertilizer.