磷肥输入对稻田土壤剖面胶体磷含量的影响  

Effects of phosphorus addition on soil colloidal phosphorus content in a paddy soil profile

作　　者：赵越[1] 梁新强[1,2] 傅朝栋 朱思睿 金熠[1] 叶玉适[1] 

机构地区：[1]浙江大学环境保护研究所,杭州310058 [2]浙江省水体污染控制与环境安全技术重点实验室,杭州310058

出　　处：《生态学报》2015年第24期8251-8257,共7页Acta Ecologica Sinica

基　　金：国家自然科学基金面上项目(41271314);国家水体污染控制与治理科技重大专项(2012ZX07506-006-03)

摘　　要：磷肥管理与土壤磷素赋存息息相关,选取杭嘉湖地区典型稻田定位实验,研究磷肥输入下稻田土壤剖面胶体磷含量的变化,分析不同施肥管理下胶体磷在土壤中的分布规律。结果表明,(1)胶体磷是磷素在土壤中赋存的重要形式,能够占到土壤胶体溶液(<1μm)总磷的85%以上,土壤全磷的0.1%—2%;(2)磷肥施用增加了土壤胶体磷含量,特别是在有机肥处理下0—5 cm土壤胶体磷含量达到了8.0 mg/kg;(3)随着土壤深度的增加,胶体磷含量减少,有机肥输入下对深层土壤胶体磷含量的影响较无机肥明显;(4)水稻收割后表层土壤胶体磷含量与油菜收割后相比减少明显,0—5 cm土壤胶体磷含量减少了90%左右,但有机肥施用下胶体磷含量减少较小;(5)水稻收割后30—60 cm土壤胶体磷含量有所增加,可能与胶体磷发生的纵向迁移有关。了解磷肥输入对稻田土壤剖面胶体磷含量的影响,为研究土壤磷素赋存形态及迁移变化提供科学依据,对有效评估胶体磷的环境风险起到指导作用。Phosphorus （P） fertilization must be conducted with a clear understanding of P forms and their distribution in the soil profile. Excessive application of P fertilizers could eventually cause P accumulation, especially in the topsoil. P loss from a nutrient-enriched agricultural field can lead to eutrophication of water bodies, which has been a recent global concern. Traditionally, the P obtained after filtering a soil solution by using a 0.45-μm microporous membrane is defined as ＂particulate＂ or ＂dissolved＂ P species. Compared to the immobile soil matrix, colloidal particles （size, typically, between 1 nm and 1 μm） have larger surfaces and stronger sorption capacities. Colloid-facilitated P transport in agricultural soils has received much attention in recent decades because the binding of P species to colloidal particles can largely enhance its mobility. Therefore, colloidal P is an important contributor of P according to soil particle size fractionation, and it plays a significant role in the distribution, transformation, and variation of P in the soil environment. However, to date, few studies have shown the changes in soil colloidal P under long-term P fertilization. This study was based on long-term field experiments conducted in Hangjiahu Plain. We measured the changes of soil colloidal P contents and analyzed its distribution characteristics in a paddy soil profile, under different fertilization managements. Four P fertilizer treatments were applied： no fertilizer control （CK）, low P fertilizer （P1, 26 kg P/hm2） , high P fertilizer （P2, 39 kg P/hm2） and manure treatment （M, 26 kg P/hm2）. Soil samples were collected ＇after oilseed rape and rice harvests, and the soil profiles were divided into four layers, 0--5, 5--30, 30--60, and 60--100 cm. Soil total P concentration, mass of soil colloidal particles, and colloidal and truly dissolved P in water extraction were determined. Soil colloidal and truly dissolved P were determined using extraction with water, centrifugatio

关 键 词：磷肥管理 土壤剖面 胶体磷 

分 类 号：S153.6[农业科学—土壤学] S143.2[农业科学—农业基础科学]