Influence of earthworms on soil properties and grass production in reclaimed cutover peat

The effects of earthworms on grass growth and soil structure in reclaimed peat were studied in a glasshouse bucket experiment, Cumulative grass yields from 13 cuts taken over a period of 20 months were 89% higher in organically fertilized and 19% higher in inorganically fertilized buckets with earthworms than in similarly fertilized buckets without earth worms. When fertilizers were withheld from some buckets after 7 months grass growth during the remainder of the study was significantly greater in the presence of earthworms under both organic (+222%) and inorganic (+114%) regimes. It is considered that grass growth responses were mainly due to enhanced organic matter decomposition and mineralization. Soil subsidence rates, hydraulic conductivity: moisture characteristics, bulk density, porosity, fibrosity, and soil morphology and micromorphology were significantly influenced by earthworm activity. The results show that earthworm activity can significantly accelerate the process of maturation and profile development in reclaimed peat soils.