• ISSN 1008-505X
  • CN 11-3996/S
丁佳惠, 王祺, 樊秉乾, 张帅, 崔建宇, 胡兆平, 陈清. 乙二胺四乙酸和柠檬酸活化石灰性土壤磷素的潜力评估[J]. 植物营养与肥料学报, 2020, 26(2): 362-369. DOI: 10.11674/zwyf.19098
引用本文: 丁佳惠, 王祺, 樊秉乾, 张帅, 崔建宇, 胡兆平, 陈清. 乙二胺四乙酸和柠檬酸活化石灰性土壤磷素的潜力评估[J]. 植物营养与肥料学报, 2020, 26(2): 362-369. DOI: 10.11674/zwyf.19098
DING Jia-hui, WANG Qi, FAN Bing-qian, ZHANG Shuai, CUI Jian-yu, HU Zhao-ping, CHEN Qing. Activation potential of soil legacy phosphorus by EDTA and citric acid evaluated with consecutive extraction method in the calcareous soil[J]. Journal of Plant Nutrition and Fertilizers, 2020, 26(2): 362-369. DOI: 10.11674/zwyf.19098
Citation: DING Jia-hui, WANG Qi, FAN Bing-qian, ZHANG Shuai, CUI Jian-yu, HU Zhao-ping, CHEN Qing. Activation potential of soil legacy phosphorus by EDTA and citric acid evaluated with consecutive extraction method in the calcareous soil[J]. Journal of Plant Nutrition and Fertilizers, 2020, 26(2): 362-369. DOI: 10.11674/zwyf.19098

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

  • 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152 mg/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%、14.9%和37.1%、5.4%。此外,柠檬酸处理还降低了31.4%的土壤Al-P,EDTA和柠檬酸在改良土壤上对于各组分磷的浸提量与在高磷土壤上相似。
    结论 在连续浸提的条件下,EDTA 和柠檬酸在低磷土壤上无明显活化磷素的效果,而在高磷土壤上和施入白云石的改良土壤上则可持续浸提出大于总磷量20%的磷素。高磷土壤和改良后土壤中被浸提磷素主要来自Ca2-P和Ca8-P,少部分来自Al-P和Fe-P。

     

    Abstract:
    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 extractions by deionized water, EDTA and citric acid, the soil Ca2-P content was increased in low-P soil, compared to the pristine soil. The soil Ca2-P, Ca8-P contents on the other hand were significantly decreased by 16.1%, 14.9% and 37.1%, 5.4% in high-P soils extracted with the EDTA and citric acid, respectively, compared with those extracted with the deionized water. In addition, the soil Al-P content was significantly decreased by 31.4% with citric acid extraction. In the DA-soil, EDTA and citric acid showed similar extracting capacity on the change of the soil P content.
    Conclusions Both EDTA and citric acid may not possible to activate too much P from low-P soil, while may activate more than 20% of total P in the long run in the high-P soil, even though amended with dolomite. The activated P are mainly from Ca2-P and Ca8-P, and a small proportion from Al-P and Fe-P.

     

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