Corn cob biochar improves aggregate characteristics of a tropical sandy loam

Abstract

Most tropical soils are highly weathered and are vulnerable to soil erosion due to their poor aggregate characteristics. Soil aggregate characteristics are critical indicators of soil structural stability, and they have the propensity to influence soil physical behavior and functioning. In this study, we investigated the effect of corn cob biochar on the aggregate characteristics of a highly weathered tropical sandy loam. Biochar significantly increased soil organic carbon by 22-40% relative to the untreated soil with a surprising trend of increasing water dispersible clay as biochar rate increased. Amount of water stable aggregates was significantly improved by 15 – 34% in biochar treatments compared to control. Incorporation of biochar decreased the tensile strength of the large aggregates (4–8 mm and 8–16 mm), but increased same in the smaller aggregates (1–2 mm). Soil friability and workability were significantly improved in the BC-20 and BC-20+P treatments