Efficacy of soil amendments on modifying select chemical properties of soil beneath durian canopies in the Tha Mai soil series

Abstract

Study on the efficacy of soil amendments on modifying selected chemical properties of soil beneath durian canopies in the Tha Mai soil series. This research was conducted from February 2023 to January 2024. The soil amendment utilized in the experiment primarily consisted of rice husk biochar (sourced from a biomass power plant), vermicompost, cow manure, chicken manure, coconut coir, and raw rice husks, mixed in a ratio of 2:1:1:1:1:1, respectively. Soil samples were collected at a depth of 15 centimeters. The experimental design employed was a Randomized Complete Block Design (RCBD) comprising six treatments: 1) Control (no soil amendment), 2-6) Soil amendment applications at rates of 2.5, 5, 10, 15, and 20 kilograms per tree, respectively. Selected chemical properties of both the soil amendment and the soil beneath durian canopies were analyzed before and six months after the application of the soil amendment. Results indicated that after six months, the addition of soil amendment at a rate of 20 kilograms per tree significantly increased soil pH from 4.2 to 6.0 (p<0.05). Furthermore, this treatment led to increases in organic matter content, phosphorus, potassium, calcium, magnesium, iron, copper, and zinc. However, no statistically significant differences were observed in the levels of exchangeable copper, manganese, and zinc in the soil (p>0.05). The findings demonstrate that the application of soil amendment at a rate of 20 kilograms per tree can effectively improve soil pH and enhance nutrient content in the soil beneath durian canopies.