Organic anion-to-acid ratio influences pH change of soils differing in initial pH

Abstract

Purpose: This study aimed to investigate the effect of initial soil pH and organic anion-to-acid ratio on changes in soil pH. Materials and methods: Two soils (Podosol and Tenosol) along with two carboxylic acids (malic and citric acid) and their anions (sodium malate and citrate), commonly found in plant residues, were used in this study. Stock solutions of either malic acid and disodium malate or citric acid and trisodium citrate were added to pre-incubated soils at anion-to-acid ratios of 0:100, 10:90, 25:75, 50:50, 75:25, 90:10, 100:0 and at 0.25 g C kg-1 soil. Soils were adjusted to 80 % field capacity and mixed thoroughly, and three replicates of 50 g of each soil were transferred into..