长期施肥对旱地红壤磷素饱和度的影响  

Effects of Long-term Fertilization on the Degree of Phosphorus Saturation in Upland Red Soils

作　　者：许杏红 王艳玲 殷丹 樊剑波[2] XU Xing-hong;WANG Yan-ling;Yin Dan;FAN Jian-bo(International Center far Ecology,Meteorology and Environment,College of A pplied Meteorology,Nanjing University of Information Sciences and Technology,Nanjing 210044,China;Farmland Ecosystem National Field Observation and.Research Station,Nanjing Institute of Soil Science,Chinese Academy of Sciences,Yingtan 335000,China)

机构地区：[1]南京信息工程大学应用气象学院生态气象环境研究中心,江苏南京210044 [2]江西鹰潭农田生态系统国家野外科学观测研究站(中国科学院南京土壤研究所),江西鹰潭335000

出　　处：《土壤通报》2019年第4期870-877,共8页Chinese Journal of Soil Science

基　　金：国家自然科学基金项目(41571286;41571130053)资助

摘　　要：磷素饱和度(Degree of phosphorus saturation,DPS)能够有效评估土壤磷素的流失潜能及地表水磷富营养化问题,可用于评价土壤磷素环境风险。DPS值通常由酸性草酸钱提取态磷(PQ与提取态铁铝(FemAlQ的摩尔质量比除以校正常数(Corrected constant,a)计算得到,而a是通过建立土壤饱和吸磷量与影响土壤磷吸附的土壤特征值间的相关关系而计算得到的数值;a的取值大小(常取0.5)会直接影响到DPS的准确估算。因此,本文以中国科学院红壤生态实验站(28。04,~28。37取,116°4 r^117。09馆)为依托,以长期施肥(1988-2014年)的旱地红壤为研究材料,通过两种计算方法得到了土壤的DPS值,分析了校正常数a=0.5在长期施肥的旱地红壤DPS计算中的适用性,并确定了长期施肥旱地红壤DPS计算中a的适用性阈值。研究结果表明:校正常数a=0.5虽适用于长期施肥旱地红壤DPS的估算,但易导致旱地红壤DPS的过高估算;对比计算发现,长期施肥旱地红壤DPS计算时,校正常数a的最适取值范围为0.71-0.81。但是,不同环境背景下旱地红壤DPS计算公式中校正常数a的适应性阈值仍需进一步校正与验证,从而提高红壤区土壤磷素环境风险评估的准确性。Estimating the loss of soil phosphorus(P)and its potential effect on surface water eutrophication could be effectively predicted by the degree of P saturation(DPS)of soil,which is an important indicator used widely for the evaluation of soil P environmental loss risk.The DPS value is usually calculated by Pflx/[a x(Fenx+Alox)],the corrected constant a(usually at 0.5)depends on soil type and directly affects the accurate estimation of DPS.Therefore,the objectives of this study were to discuss the applicability of a of 0.5 and to determine the new adaptability of a during the calculation of DPS in the upland red soils.Soil samples were collected from Red Soil Ecological Experiment Station of Chinese Academy of Sciences(28°04‘~28°37'N,116°41'〜117°09z E)under the long-term fertilization.The P sorption capacity(PSC)and the corrected constant a were used to calculate the different DPS values.Although the corrected constant a of 0.5 was suitable for the estimation of DPS in the upland red soil under the long-term fertilization,and the results were higher than the true values.The corrected constant a at 0.71〜0.81 was suitable for the DPS calculation in the upland red soils under the long-term fertilization.Each soil type should have an exclusive corrected constant a.The applicable threshold for the corrected constant a in the DPS estimation of red soils under different environmental contexts should be further calibrated and verified in order to improve the accuracy of soil P environmental risk assessment.

关 键 词：长期施肥 旱地红壤 磷素饱和度 土壤磷吸持容量 校正常数a 

分 类 号：S158.5[农业科学—土壤学] X825[农业科学—农业基础科学]