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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #407358
Research Project: Sustaining Productivity and Ecosystem Services of Agricultural and Horticultural Systems in the Southeastern United States

Location: Soil Dynamics Research

Title: Relationship between pH and base saturation associated with soil cation exchange capacity in soils of Mato Grosso do Sul, Brazil

Author
item DE ALBUQUERQUE, CARLA - Federal University Of Technology - Parana
item GAVELAKI, FABIANA - Federal University Of Technology - Parana
item MATERA, HENRIQUE - Federal University Of Technology - Parana
item MOTTA, ANTÔNIO - Federal University Of Technology - Parana
item Prior, Stephen - Steve
item ERCOLE, TAMIRES - Federal University Of Technology - Parana
item ARAÚJO, ELOÁ - Federal University Of Technology - Parana

Submitted to: Bragantia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/21/2024
Publication Date: 5/3/2024
Citation: De Albuquerque, C.G., Gavelaki, F., Matera, H.B., Motta, A.C., Prior, S.A., Ercole, T.M., Araújo, E.M. 2024. Relationship between pH and base saturation associated with soil cation exchange capacity in soils of Mato Grosso do Sul, Brazil. Bragantia. 83:e20230291. https://doi.org/10.1590/1678-4499.20230291.
DOI: https://doi.org/10.1590/1678-4499.20230291

Interpretive Summary: Knowledge on factors influencing soil acidity is important in managing agricultural cultivation and ensuring environmental sustainability. However, the relationship between soil pH and base saturation (V%) including the influence of cation exchange capacity has been poorly studied in Brazil. A large dataset (30,244 analyses of soils collected from 0-20 and 20-40 cm depths) was used to target this topic. Prediction of V% versus pH was affected by CEC. Decreased correlations were related to low clay content (17%) of soils with low CEC, which provided low buffering power. For soils with higher CEC and higher clay content (45%), there was greater buffering power associated with kaolinite. Thus, soil CEC, texture, and buffering power should be evaluated in isolation to better understand the relationship between V% and pH. With better understanding of this dynamic, liming method can be more efficient by not compromising availability of other nutrients or losing nutrient bases by leaching.

Technical Abstract: Soil pH and base saturation are very important parameters for evaluating effects of acidity on plant growth. However, the relationship between soil pH and base saturation (V%) has been poorly studied in Brazil. The goal was to evaluate the influence of cation exchange capacity (CEC) on this relationship for soils of Mato Grosso do Sul (Brazil) using a large database consisting of 30,244 analyses of soils collected from 0-20 and 20-40 cm depths. The CEC at pH 7.0 of analyzed soils varied from 3.4 to 40.5 cmolc·dm-3 and were grouped into four classes (< 6, 6-10, 10-20, and > 20 cmolc·dm-3) for each soil layer. The V% versus pH relationship was CEC dependent for both soil layers. For 0-20 cm, V% was directly related to CEC (< 6, 6-10, 10-20, and > 20 cmolc·dm-3) and reached 50, 55, 60, and 74 % at pH 5 and 66, 73, 81, and 88 % at pH 6.0, respectively. Prediction of V% versus pH was also affected by CEC, with a decrease in the correlation of p = 0.82 for CEC < 6 cmolc·dm-3 to p = 0.64 for CEC > 20 cmolc·dm-3. The decrease in this correlation was related to low clay content (17%) of soils with CEC < 6 cmolc·dm-3, which provided low buffering power. For soils with CEC > 20 cmolc·dm-3 and higher clay content (45%), there was greater buffering power associated with kaolinite. Findings suggest that CEC should be considered in order to understand the relationship between V% and pH CaCl2.