县域农田土壤磷素积累及淋失风险分析——以北京市平谷区为例  

Evaluation of Soil Phosphorus Accumulation and Loss Risk on Arable Land at County Level:The Example of Pinggu District, Beijing City, China

作　　者：柏兆海[1] 万其宇[1] 李海港[1] 段增强[1] 陈清[1] 

机构地区：[1]中国农业大学资源与环境学院,北京100193

出　　处：《农业环境科学学报》2011年第9期1853-1860,共8页Journal of Agro-Environment Science

基　　金：公益性行业(农业)科研专项"农作物最佳养分管理技术研究与应用"(201103003);北京市果类蔬菜产业创收团队

摘　　要：作物的磷素需求和投入的差异导致土壤磷素积累对环境的影响不同。通过分析京郊平谷区果树、蔬菜和粮食作物的磷素投入数量和农田土壤有效磷含量,比较研究不同作物体系中土壤磷素积累对环境的影响。结果表明,粮田、菜地和果园平均年际磷投入量分别为76、575kgP2O5·hm-2和693kgP2O5·hm-2,其中菜地和果园的磷素投入以有机肥为主,年际磷盈余分别达到498kgP2O5·hm-2和468kgP2O5·hm-2,远大于粮田的磷素盈余(38kgP2O5·hm-2)。这种状况造成粮田、菜地和果园土壤Olsen-P含量差异很大,分别为18.4(n=260)、44.3(n=108)mg·kg-1和40.4mg·kg-1(n=548)。分析钙质土壤Olsen-P与CaCl2浸提P的相关性发现,钙质土壤存在着Olsen-P与CaCl2-P突变拐点即磷的淋溶拐点,在拐点之后土壤CaCl2-P随土壤Olsen-P的增加而显著增加,且土壤磷淋溶拐点明显受土壤类型及质地的影响。按质地分类,砂壤、轻壤和重壤拐点分别是23.1、40.1mg·kg-1和51.5mg·kg-1,土壤质地由轻至重拐点Olsen-P值随之逐渐增加。根据质地模拟,7.7%的粮田、44.0%的菜田、33.6%的果园土壤磷淋失风险较高。因此,合理的磷素投入在果树、蔬菜作物的可持续生产中具有重要的意义。The variation of phosphorus demand and input among different cropping system may cause the different surplus and risk to environment. The aim of this study is to evaluate the difference of soil phosphorus （P） accumulation and potential risk of P loss to environment among cereal, fruit and vegetable cropping systems in Pinggu District, Beijing suburb, through field survey on phosphorus application and soil analysis. The results showed that the average P input was 76, 575 kg P2O5· hm^-2 a-^-1 and 693 kg P2O5· hm^-2 a-^-1in cereal, vegetable and orchard systems, respectively. Manure P was the main proportion of the total P input in vegetable and orchard systems and P surplus was 468 kg P2O5· hm^-2 a-^-1 and 498 kg P2O5· hm^-2 a-^-1, which was much higher than that in cereal system （38 kg P2O5· hm^-2 a-^-1 ）. This caused high variation in soil Olsen-P content, which was 18.4, 44.3 mg· kg^-1 and 40.4 mg· kg^-1for cereal （n=260）, vegetable （n= 108 ） and orchard （n=548） system, respectively. It was found that there were change-points when soil CaCl2-P rapid increased with soil Olsen-P was 23.1, 40.1 mg· kg^-1and 51.5 mg· kg^-1 for sandy loam, light loam and heavy loam soils, respectively, through the correlation analysis between soil Olsen-P and CaCl2 extracted P contents. The value of change-point was significantly higher in clay soils than loam soils. As classified with soil texture, 7.7%, 44.0% and 33.6% of the surveyed fields were with high P leaching potential in cereal, vegetable and orchard cropping system, respectively. It is necessary to manage P input in vegetable and orchard system following crop requirement and soil P fertility.

关 键 词：Olsen—P CaCl2-P 拐点 磷淋溶风险 粮田 果园 菜田 

分 类 号：X820.4[环境科学与工程—环境工程]