USING THE REGRESSION MODEL TO ESTIMATE THE INFILTRATION RATE FROM SOIL PROPERTIES AFTER SHIFTING CULTIVATION IN VIETNAM
Authors: Tran Xuan Minh*, Nguyen Dinh Vinh, Ta Thi Binh, Hoang Thi Mai, and Nguyen Thi Huong Giang
Forestry Ideas
: 2/29 : 300-313
Publishing year: 11/2023
The aim of the study was: (i) to measure the different soil properties and infiltration rate; (ii) to determine the optimum soil infiltration rate model based on soil properties (soil porosity, bulk density, soil moisture, organic matter, clay, silt and sand) after shifting cultivation in Vietnam. Infiltration rates were measured using a double-ring infiltrometer at 36 sampling points, and the measurements were taken from February to June 2020. Location of each infiltration stations were marked using GPS device. The results showed that the infiltration rate in vegetation recovering (grassland, shrubland and small regenerating trees) after shifting cultivation varied from 2.41 to 3.23 mm·min-1, with an average measured infiltration rate of 2.87 ±0.22 mm·min-1. The soil poros- ity, organic matter content and sand have a positive correlation with infiltration rate, whereas bulk density, soil moisture, clay, silt have a negative one. The analysis performed for five models con- sidering the combination of soil properties and subjected to regression analysis. Result showed that in order to predict soil infiltration rate based on few properties of soil with four independent variables, multi-linear regression model IR = 1.745 + 0.026 (SP) + 0.016 (OM) - 0.026 (SM) + 0.003 (sand) with the coefficient of determination R2 = 0.856, Bayesian Information Criterion (BIC) = -55.77 and posterior probability = 15.5 % is the best model for the estimation of infiltration rate and recommended for the research area.
bulk density, multi-linear regression, organic matter, soil moisture, soil porosity