摘要
维持适宜的土壤有效磷水平对保障蔬菜产量和水体安全具有十分重要的作用。而当前蔬菜种植体系磷肥投入的显著特征是高量、高频次,导致大量磷素累积在土壤中会增加磷素移动性从而引发高环境风险。一般认为菜地磷的环境阈值高于农田,但菜地的灌水和磷肥投入均远高于农田,因此磷流失程度仍高于农田。综合文献调研结果发现,我国不同地区的菜地土壤Olsen-P的环境阈值存在较大差异,集中在P 60.0~80.0 mg/kg。菜地有效磷水平通常高于环境阈值,而农田有效磷水平普遍低于环境阈值,表明菜地磷损失风险更大。同时蔬菜磷的农学阈值高于粮食作物的现象普遍,反映蔬菜对磷的高需求,而仅通过减少磷肥施用达到降低菜地磷损失风险的目的可能会导致蔬菜减产。因此,了解磷素在菜地土壤中的累积现状及特征,在明确蔬菜高产和环境友好的土壤有效磷农学和环境阈值的基础上,通过优化施磷量将土壤有效磷维持在既能满足蔬菜高产需求又能降低磷流失风险的合理水平,才能实现菜地磷养分的最佳管理。
Maintaining an appropriate soil available phosphorus(P)level is vital to ensure vegetable production and water safety.The significant feature of the current vegetable production system’s phosphate fertilizer input is massive and frequency,which causes a large amount of P accumulated in the soil,further,increasing the movement of P and causing environmental risks.It is generally believed that soil P environmental threshold of vegetable fields is higher than that of farmland,however,the irrigation and phosphate fertilizer application of vegetable fields were much higher than those of farmland.Therefore,P is still easier to loss from vegetable fields than farmland.Results of literature investigation showed that,environmental thresholds of vegetable fields varied among different regions in our country,mainly within P 60.0–80.0 mg/kg.The available P contents in vegetable fields were usually higher than their environmental thresholds,while the available P contents in croplands were usually lower than their environmental thresholds,which meant the vegetable fields had higher environmental risks than croplands.Furthermore,we found that there was a common phenomenon that the agriculture threshold of vegetable P is higher than that of cereal crops,reflecting high P requirement of vegetables.Therefore,only reducing the amount of phosphate fertilizer to mitigate the risk of P loss in vegetable fields might lead to vegetable production decline.Accordingly,on the basis of understanding the current status and characteristics of P accumulation in vegetable fields,and clarifying the agriculture and environmental threshold of soil available P for high vegetable yield and sustainable development of vegetable production,soil available P can be maintained at a level that meet the high-yield demand of vegetable plants and low P loss by optimizing the amount of P,thus achieving the best P management in vegetable fields.
作者
王瑞
仲月明
李慧敏
施卫明
李奕林
WANG Rui;ZHONG Yueming;LI Huimin;SHI Weiming;LI Yilin(State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《土壤》
CAS
CSCD
北大核心
2022年第1期1-8,共8页
Soils
基金
国家自然科学基金项目(31872957)资助。
关键词
菜地
磷素
环境阈值
农学阈值
养分管理
Vegetable production system
Phosphorus
Environmental threshold
Agriculture threshold
Phosphorus management
