西安市设施菜地土壤养分状况分析

Analysis of Soil Nutrient Status of Protected Vegetable Fields in Xi'an

明晰施肥情况和土壤养分状况,能为区域设施蔬菜施肥管理提供一定的决策依据。研究在施肥情况调查和土样测试基础上,分析了西安市设施蔬菜化肥施用情况和设施菜地土壤养分状况。结果表明①西安市设施蔬菜氮肥施用量平均为883.05 kg·hm^(-2),磷肥施用量平均为601.50 kg·hm^(-2),钾肥施用量平均为598.05 kg·hm^(-2)。与推荐施肥标准比较,所有样点氮肥施用量整体偏高,磷肥施用量整体偏大过量明显,钾肥施用过量和不足问题并存。②与耕地相比,设施菜地土壤有机质和碱解氮富集不明显;土壤有效磷和速效钾富集极为明显,分别高出耕地的389.92%和46.49%;土壤pH达到8.06,高出耕地0.47个单位,出现碱化趋势。根据菜地土壤养分含量分级标准,设施菜地土壤有机质、碱解氮丰富和缺乏现象并存,土壤有效磷、速效钾主要表现为盈余。③随种植年限增加,设施菜地土壤有机质和pH呈现出先降低后升高的趋势,而碱解氮、有效磷、速效钾含量均呈现出逐渐增加的趋势,土壤速效养分出现累积趋势明显。实际农业生产过程中,应在重视设施蔬菜优质有机肥投入基础上,更加注重平衡施肥,以降低设施菜地面源污染环境风险,并达到节本、增效和增收目的。

Making clear the fertilization situation and soil nutrient status can provide certain decision-making basis for fertilization management of regional protected vegetables.Based on the investigation and soil sample test,the fertilizer application and soil nutrient status of protected vegetable fields in Xi'an were analyzed.The results showed that:①the average application amount of nitrogen fertilizer was 883.05 kg·hm^(-2),of which phosphorus fertilizer was 601.50 kg·hm^(-2),and potassium fertilizer was 598.05 kg·hm^(-2).Compared with the recommended fertilization standard,the overall application amount of nitrogen fertilizer and phosphate fertilizer at all sample points were relatively high,and the problems of overdose and insufficient were coexist in potassium fertilizer application.②Compared with cultivated land,the accumulation of soil organic matter and alkali-hydrolyzable nitrogen in the greenhouse vegetable soil were not obvious;the soil available phosphorus and available potassium were extremely enriched,which were 389.92%and 46.49%respectively higher than that of the cultivated land;the soil pH reached 8.06,which was 0.47 units higher than that of arable land,showing a trend of alkalization.According to the vegetable soil nutrient content classification standard,abundant and insufficientuses were coexist in the organic matter and alkali-hydrolyzable nitrogen of the vegetable soil,and the soil available phosphorus and potassium were mainly surplus.③With the increase of planting years,soil organic matter and pH showed a trend of decrease at first and then increase,while the contents of alkali hydrolyzable nitrogen,available phosphorus and available potassium showed a trend of gradually increasing,and the accumulation trend of soil available nutrients was obvious.In the actual agricultural production process,we should pay more attention to balanced fertilization on the basis of high-quality organic fertilizer input of facility vegetables,so as to reduce the environmental risk of non-point source pollution in greenhouse vegetable field,and achieve the purpose of cost-saving,efficiency-increasing and income-increasing.