乙二胺四乙酸和柠檬酸活化石灰性土壤磷素的潜力评估  

Activation potential of soil legacy phosphorus by EDTA and citric acid evaluated with consecutive extraction method in the calcareous soil

作　　者：丁佳惠 王祺[1] 樊秉乾 张帅 崔建宇[1] 胡兆平 陈清[1,3] DING Jia-hui;WANG Qi;FAN Bing-qian;ZHANG Shuai;CUI Jian-yu;HU Zhao-ping;CHEN Qing(College of Resources and Environmental Sciences,China Agricultural University,Beijing 100193,China;Kingenta Ecological Engineering Group Co.,Ltd.,Linyi,Shandong 276700,China;State Key Laboratory of Nutrition Resources Integrated Utilization,Linyi,Shandong 276700,China)

机构地区：[1]中国农业大学资源与环境学院,北京100193 [2]金正大生态工程集团股份有限公司,山东临沂276700 [3]养分资源高效开发与综合利用国家重点实验室,山东临沂276700

出　　处：《植物营养与肥料学报》2020年第2期362-369,共8页Journal of Plant Nutrition and Fertilizers

基　　金：国家重点研发计划(2016YFD0801006);现代农业产业技术体系专项(CARS-23-B16)。

摘　　要：【目的】长期施磷形成的高磷残留土壤,面临土壤酸化、钙镁离子淋失等问题。本研究采用肥料中常见的螯合剂乙二胺四乙酸(EDTA)和柠檬酸,研究其对不同磷含量的石灰性土壤中磷素的活化作用,以期为磷肥减施和土壤残留磷高效利用提供有效途径。【方法】供试低磷、高磷和白云石改良土壤取自北京市房山区的石灰性土壤,3种供试土壤的全磷含量依次为0.95、1.90和1.91 g/kg,有效磷含量依次为7.39、160和152mg/kg。采用室内往复振荡浸提方法,两种浸提剂为EDTA和柠檬酸,低磷土壤浸提剂浓度为0.05 g/L,浸提时间为12 h,高磷土壤和改良土壤浸提剂浓度均为0.5 g/L,浸提时间分别为12 h和1 h。每个土壤样品采用相同方法连续浸提10次,同时以去离子水浸提作为对照。测定了浸提液中磷、钙、镁、铁、铝含量,计算各元素的单次浸提量和累积浸提量。全部浸提后,用蒋顾磷分组法测定了土壤中不同组分磷的含量。【结果】EDTA和柠檬酸在低磷土壤中单次磷素浸提量均较低,且累积浸提量之间差异不显著,连续浸提10次后磷素的累积浸提量不及土壤全磷的3%;而在高磷土壤和施入白云石的改良土壤中,柠檬酸和EDTA的单次磷素浸提量为低磷土壤的7~64倍,磷素累积浸提量超过土壤总磷的20%,且柠檬酸处理高于EDTA处理。在低磷土壤中,磷素的累积浸提量仅与铁和铝离子的累积浸提量显著相关,在高磷土壤中,磷素的累积浸提量与钙、镁、铁和铝离子的累积浸提量均显著正相关,且相关系数均在0.78以上,而在白云石改良土壤中,磷素的累积浸提量与铝离子的累积浸提量之间无显著相关关系。进一步分析浸提前后土壤磷素组分变化可知,在低磷土壤中,去离子水、EDTA和柠檬酸经10次浸提后土壤Ca2-P显著增加;在高磷土壤中,EDTA和柠檬酸处理浸提的土壤Ca2-P、Ca8-P较去离子水处理显著降低了16.1%、1【Objectives】Long-term phosphorus(P)application causes the occurrence of high residual but low available P in soil,in which soil acidification and leaching of Ca2+and Mg2+are prone to occur.We investigated the effect of using EDTA and citric acid to activate the P in calcareous soils,thereby providing a theoretical basis for reducing P fertilizer application and increasing P use efficiency.【Methods】All the calcareous soils were collected from Fangshan district,Beijing.The total P contents in low-P,high-P and dolomite amended(DA-soil)soils were 0.95,1.90 and 1.91 g/kg,and available P contents were 7.39,160 and 152 mg/kg,respectively.Indoor sequential extraction method was used to simulate the activation of P from soils,with EDTA and citric acid as extractants.In low-P soil,the concentrations of EDTA and citric acid were 0.05 g/L and extracting time was 12 h;in high-P soil and DA-soil,the concentrations were 0.5 g/L and extracting time were 12 h and 1 h.The extraction were repeated 10 times,with deionized water as control.The contents of P,Ca,Mg,Fe and Al in the extracts were measured,and the cumulative extracting amount of each element was calculated.Soil P fraction was conducted at the end of extraction.【Results】In low-P soil,both EDTA and citric acid were not significantly effective on the cumulatively extracted P which accounted for<3%of the soil total P(TP).However,in high-P soil and DA-soil,both of EDTA and citric acid exhibited a strong P extracting capacity and the cumulatively extracted P accounted for more than 20%of the TP.Generally,the extracting amount of P in the high-P soil and DA-soil was 7-64 times higher than that in the low-P soil.And,citric acid extracted more P than EDTA(P<0.05).The extracted P by deionized water,EDTA and citric acid were all significantly and positively correlated with the extracted Al and Fe in the low-P soil,significantly and positively correlated with Al,Fe,Ca and Mg in the high-P soil(r>0.78),but not significantly correlated with Al in the DA-soil.After 10 extra

关 键 词：连续浸提 EDTA 柠檬酸 土壤含磷量 磷素活化 活化磷形态 

分 类 号：S153.6[农业科学—土壤学]