节水控氮对黄河上游地区设施菜田氮素时空分布的影响

为了探索黄河上游地区日光温室节水控氮对氮肥利用效率及氮素运移规律的影响,以不同施氮量和灌水量为试验处理,采用随机区组处理方式,通过在西芹不同生长阶段、0～160cm土壤剖面获取土壤氮素的动态变化信息,以评价日光温室栽培条件下土壤氮素运移规律和硝态氮的淋溶情况。试验表明:在耕层土壤(0～60cm)内全氮质量分数变化较大且规律明显;硝态氮质量分数变化在整个生长周期内呈规律性明显变化,且土壤中硝态氮质量分数变化与灌水量呈负相关关系,与施氮质量分数呈正相关关系,节水控氮能够有效减轻土壤中上层中(0～60cm)硝态氮淋洗,降低土壤硝态氮积累量,有效减轻对农田周围水体污染。

Effect of Water Saving and Nitrogen Controlling on Nitrogen Temporal and Spatial Distribution in Greenhouse Vegetable Fields of Upstream Area of the Yellow River

In order to explore effect of water saving and nitrogen controlling on nitrogen use efficiency and nitrogen transport law,adopting randomized block designs,to obtain dynamic change information on soil nitrogen to evaluate soil nitrogen transport law and nitrate leaching in different growth stages of celery,in 0～160 cm soil profiles in greenhouse in the upper reaches of the Yellow River.The results showed that at the same nitrogen application rate,soil total nitrogen gradually increased(treatment 1treatment 2>treatment 5) in 20～40 cm and in 40～60 cm,with the decrease of irrigation quota,total nitrogen mass fraction,and the law was changed greatly in the topsoil(0～60 cm);NO3-N changed regularly,which was a n egative correlation with irrigation quantity,which was a positive correlation with nitrogen application rate during growing periodicity