Indian Journal of Agricultural Research

SCOPUSWeb of Science
  • Year: 2024
  • Volume: 58
  • Issue: 1

Effects of Electrolytes and Soil-to-suspension Ratios on pH in Acidic-coarse Textured Soil

  • Author:
  • Somchai Butnan1,*, Pranee Sriraj2, Banyong Toomsan3
  • Total Page Count: 6
  • Page Number: 120 to 125

1Plant Science Section, Faculty of Agricultural Technology, Sakon Nakhon Rajabhat University, Sakon Nakhon, 47000, Thailand

2Department of Thai Traditional Medicine, Faculty of Natural Resources, Rajamangala University of Technology Isan, Sakon Nakhon, 47160, Thailand

3Department of Agronomy, Faculty of Agriculture, Khon Kaen University, Khon Kaen, 40002, Thailand

Abstract

Soil pH is determined using a variety of methods. The key differences among them are the electrolytes and soil-to-suspension ratios. However, an optimal procedure tailored to a particular soil is required. This study, therefore, aimed to evaluate the effects of electrolytes and soil-to-suspension ratios on soil pH and to optimise pH measurement methods for acidic-coarsely textured soil.

Varied standard electrolytes (water, 0.01 M CaCl2 and 1 M KCl) and soil-to-suspension ratios (1:1, 1:2.5 and 1:5 w/v) were used to measure the pH of thirty samples of acidic-coarsest textured soil.

Soil pH values were observed in the following order: water > 0.01 M CaCl2 > 1 M KCI. Higher soil pHs were a result of higher suspension volumes. The most optimal pH measurement method for an acidic-coarsely textured soil was obtained from the 1:2.5 soil-to-suspension ratio of 1 M KCl, which held the highest R2 (0.850), as well as the lowest root mean square error (RMSE) (0.010), indicating the most precise method. An alternative method suitable for a cost-saving laboratory was the 1:1 soil-to-suspension ratio of 0.01 M CaCl2, which owned R2 of 0.766 and RMSE of 0.013, as its pH measurement was similar to those under the most optimal method.

Keywords

Acid soil, Hydrogen ion concentration, Ionic strength, pH assessment, Soil reaction