EVALUATION OF THE COMBINED APPLICATION OF AMENDMENTS (LIME, BIOCHAR AND ORGANIC ACIDS) ON ACID SOIL (GLEYSOLS) IN VUNG LIEM, VINH LONG: SURVEY OF pH AND pH BUFFERING CAPACITY

Abstract

Soil acidification is increasingly serious due to the use of chemical fertilizers, continuous intensification in agricultural production has affected the yield of crops. The objective of the study was to evaluate the applicability of combined amendmenders such as lime, biochar derived from pyrolysis coffee husks at 300℃ and organic acids in improving pH and pH buffering capacity (pHBC) of the acid soil of Vung Liem, Vinh Long. Some parameters of soil (Density, density, pH, OC) and biochar (recovery yield, OC, pH, pHpzc, number of groups H+, OH-, CEC) were determined. The study was carried out through soil incubation and simulated acidification experiments. The research was conducted based on the combination of lime, organic matter, and biochar and was carried out through soil incubation and simulated acidification experiments. With 3 treatment series including (i) Soil mixed with lime (at the ratios of 0; 0.64; 0.85; 1.06% according to CaO); (ii) Soil mixed with lime integrated with calcium - biochar (at biochar ratios 0; 0.21; 0.42; 0.84% according to biochar); and (iii) Soil mixed with lime integrated with calcium citrate (at ratios of 0; 0.53; 1.05; 2.1% according to citric acid), 3 replicates for the experiments. The results showed that the treatments of integrating calcium - citrate (with 0.5% citric acid) and calcium - biochar (with 0.21% biochar) derived from 300℃ pyrolysis coffee pods both improved pH and the pH buffering capacity of the acid soil in Vung Liem, Vinh Long. Research shows that the use of lime combined with calci - biochar improves the pH as well as improves the pH buffering capacity of acidic soils in Vung Liem district, Vinh Long province.