A Simple Apparatus for Measuring Clod Breaking Strength

A simple, low cost apparatus, using proctor penetrometer and screw jack was developed for a rapid empirical assessment of clod breaking strength (CBS) of soils. The CBS values for nine soils growing rice varied from 168 to 691 kPa. with coefficients of variation between 7 and 16 per cent. The preliminary investigations on five soils (loam to silty clay loam) showed dependence of CBS on texture, organic carbon and water content of clods. The CBS increased linearly with the clay and organic carbon content, and decreased exponentially with the water content of clods.