陕西关中蔬菜设施栽培土壤中硝态氮的累积现状

研究了陕西关中主要蔬菜产区设施栽培土壤中硝态氮的累积现状,探讨了习惯施肥对土壤硝态氮累积量的影响.结果表明:多数试验菜地氮、磷、钾肥施用不合理,作物所需钾肥仅靠有机肥补充;设施栽培0～2 m土层硝态氮累积总量远远高于相邻粮田,硝态氮含量随土层加深逐渐减少,二者呈显著负相关;部分试验地1～2 m土层中硝态氮相对含量大于40%;部分区域地下水硝态氮含量接近饮用水卫生标准限值.

The Status Quo of Nitrate-N Accumulation in Vegetables Protected Fields in Guanzhong Area of Shanxi Province

The status quo of nitrate-N accumulation in vegetables protected field in Guanzhong Area of Shaanxi province was investigated.How traditional fertilizing influences the accumulation of nitrate-N in soil was studied.Results were as follows: unbalanced fertilizing phenomenons were common in protected field in Guanzhong.The ratio of nutrition was maladjusted seriously,potassium that crops required just came from organic manure.In protected field,the nitrate-N accumulation in 0~2 m soil profile was far higher than that in grain crop field.The content was higher in upper soil layer than that in lower layer.There was a significant negative interrelation between them.The relative content of nitrate-N in 1~2 m soil layer in some tested fields was over 40%.In some groundwater it approached the drinkingwater sanitation starand value.