Enzyme activity and C and N pools in soil following application of mulches

A field experiment was carried out to evaluate the effects of some mulching materials on soil biochemical properties that represent a component of soil quality and functionality.Wheat straw, dairy manure compost, and black polyethylene were used in the mulching experiments of a soil seeded with forage maize. Soil samples were taken from the surface (0-10 cm) and subsurface (10-20 cm) layers 1 and 4 mo after treatments were applied. Soil productivity, biochemical and chemical properties were determined. Compost treatment showed the highest agronomic yield due to the release of nutrients for plant nutrition and soil metabolism. Dehydrogenase activity was used as a measurement of overall microbial activity, whereas ?-glucosidase and urease hydrolase activities were determined as an expression of C and N cycles. In addition, a ratio between dehydrogenase activity and water soluble carbon (defined as "metabolic potential index") was calculated, in order to better represent soil metabolic potential. Compost-mulch treatment showed the lowest ratio values, while straw mulch had the highest value. A similar trend was found for ?-glucosidase activity. The data confirmed the validity and sensitivity of the metabolic potential index and ?-glucosidase enzyme in monitoring the change of soil biochemical properties and of soil quality during soil management practices.