不同施氮量对黄河上游地区设施芹菜产量及土壤中NO_3^--N残留的影响

Effects of Different Nitrogen Levels on Greenhouse Celery Yield and Soil NO_3^-—N Accumulation in the Upper Reaches of the Yellow River Region

针对宁夏灌区设施蔬菜生产中氮肥施用过量,造成土壤含盐量过高,土壤次生盐渍化加剧,进行土壤-芹菜系统的氮素单因子田间试验。结果表明,在一定范围内(0～30kg/667m2)增施氮肥,芹菜的维生素C含量提高,芹菜产量亦随施氮量增加而增加,而施氮水平高于30kg/667m2,维生素C含量会逐渐降低,产量也下降;施氮量为30kg/667m2时,芹菜维生素C含量、产量及植株氮素表观利用率均为最高;土壤硝态氮含量,一方面随着土层深度的增加,呈现显著下降的趋势;另一方面在同一土层内随着施氮量的增加,土壤中硝态氮含量逐渐增加。综合经济效益和生态效益,提出黄河上游地区设施芹菜氮素的优化目标供应值为30kg/667m2。

For excessive nitrogen fertilizer application in facilities vegetable production can cause high soil salt contents and secondary salinization of greenhouse soils,the nitrogen single-factor field experiment on soil-celery system was carried out to find an optimum fertilizer rate.The results showed that： application of nitrogen fertilizer,within a certain range（0-30 kg/667m2）,increasing N can increase the vitamin C content and the yield of celery.When nitrogen level was higher than 30 kg/667m2,vitamin C content and the yield reduced.The highest vitamin C content,yield and apparent N recovery by crop（ANRC） was obtained when nitrogen application rate was 30 kg/667m2.Soil nitrate nitrogen decreased with the increasing of soil depth,on the other hand,in the same soil layer the NO3——N content increased with the increasing of nitrogen fertilizer application.From analysis of economic and ecological benefits,the optimization of target nitrogen supply is 30 kg/667m2 in greenhouse celery production in the upper reaches of the Yellow River region.