IMPROVING HEAVY CONTENT IN SALINE ACID SULFATE SOIL WITH BIOCHAR APPLICATION

Abstract

The presence of heavy metals in the soil can have negative impacts on the quality of agricultural products as well as the health of consumers. The use of biochars made from agricultural residues to ameliorate the concentration of heavy metals in agricultural soils could be a potential solution that needs to be investigated. The purpose of the current study is to assess the capacity of biochars made from rice husks and longan branches to remediate heavy metals in saline acid sulfate soils. The study used the soil mixed with two types of biochars at five rates 0,7; 1,5; 3,0 and 6,0%. The experiment was conducted in a greenhouse for 60 days, and the soil in the experimental pots was sampled after 5 and 60 days to determine the exchangeable concentration of five heavy metals. The results showed that depending on the applied rate, biochar reduced the exchangeable concentration of various metals such as Cd, Ni, Pb, Sr, and Zn. The biochar rate of 6% led to the lowest metal concentration in the exchangeable form. Biochar made from rice husk was better in remediating heavy metals of the tested soil than that made from longan. The pH of the soil rose in proportion to the amount of biochar used. A decrease in the exchangeable concentration of the analyzed metals could be related to the adsorption capacity of the tested biochars as well as an increase in the pH value of the biochar-added soil. More studies on different types of biochar as well as in actual agricultural fields are in need to gain more precise conclusions for sustainable development.