Change of dry bulk density and Ksat after incubation of a soil in the presence of organic amendments

Abstract

Abstract Kamouraska Ap horizon samples were incubated in the presence of organic amendments, peat moss, straw, compost and green manure, applied at a rate equivalent to 7.5 t of carbon/ha. Water was added to reach 80% of field capacity. The soil‐amendement mixtures were incubated at 37°C for periods of 4, 8, 16, 32 or 64 weeks. Settling tests were performed using a jolting volumeter. Minimum dry bulk density (mDBD), saturated hydraulic conductivity (Ksat) and water content at field capacity were determined. For the unamended soil, mDBD corresponded to 1.1 g.cm‐3 and Ksat max to 265 cm/h. After incubation, mDBD varied from 1.02 to 1.12 g.cm‐3 and Ksat max values were generally below 150 cm/h. The results were discussed in relation to the decomposition of the organic amendments and the formation of stable aggregates.