2006 Volume 68 Issue 4 Pages 56-64
Compaction experiments on a Haplic Andosol sandy loam soil were conducted in a soil bin in order to observe the immediate effects of compost incorporation on compaction behavior characterized by penetration resistance, stress state and vertical strain. A selected type of compost processed from cattle manure and sawdust was added to the soil in proportions of 0, 79 and 132g/kg at soil water contents of 58 and 67%. Our results show that penetration resistance decreased with increasing amounts of compost at the lower water content, while the reverse occurred at the higher water content, probably due to changes in soil consistency. Similarly, the peak stresses significantly decreased as the amount of compost increased at the lower water content but this decrease was less pronounced at the higher level of soil moisture. Vertical strain was found to be greater in soil treated with compost than in control soil, indicating that soil-compost mixtures absorb stress transmission by allowing greater deformation.
