Multiple Regression Model for Predicting Cracks in Soil Amended with Pig Manure Biochar and Wood Biochar

Abstract

This study aims to understand the influence of compaction state, and the drying–wetting cycles on cracks propagation in biochar-amended soils (BAS). The objective of the study is to carry out multiple regression analysis (MRA) and develop a multiple regression model (MRM) for estimating the crack intensity in BAS based on basic soil and biochar properties. MRA can help to understand the impact of each parameter, such as compaction, plastic limit, liquid limit, biochar content (%), and the specific gravity of soil on the crack intensity. To obtain the objective, the soil and various biochar were mixed and compacted at 65% and 80% of maximum dry density (MDD). Observations were made that wood biochar (WB) had a higher resistance to crack propagation as compared with pig manure biochar (PMB). MRA shows that there is a reduction in crack intensity with an increase in the biochar content. It was also observed that as specific gravity and plastic limit (PL) increase, the crack intensity of samples also increases. The effect of PL is more pronounced in WB as compared with PMB. The proposed MRM provides a preliminary qualitative information of cracks intensity in samples when basic soil properties are known.