A "living mulching system" made up of sludge and earthworms (Eisenia fetida) were tested in a laboratory experiment with the goal of improving the biochemical and chemico-physical properties of two different agricultural soils: a clay soil (Vicarello, Italy) and a sandy-loam soil (Murcia, Spain). A sludge-earthworms mixture was layered onto the soil surface and kept moistened for 4 mo. Biochemical and chemico-physical soil properties were compared in order to assess the efficiency of living mulch as a function of soil type. The experiment showed that soil improvement starts from the activation of the microbiological processes through a gradual modification of the nutritive conditions occurring within the living mulch system due to earthworm activity. Also the physical properties of both soils were improved by increasing the total cracked area, mainly due to the formation of small (< 500 mu m) and small-medium cracks (500-1000 mu m), which represent the typical micro-habitat for soil microorganisms. In fact, in these soils a positive correlation was found between dehydrogenase enzyme activity, total shrinkage area and small-medium size cracks. The improvement of soil structure is of great agronomic relevance in that good physical properties favour water retention, oxygen diffusion and nutrient availability, which combine to improve soil quality and fertility.
Potential of on-site vermicomposting of sewage sludge in soil quality improvement
MASCIANDARO, GRAZIA;IANNELLI, RENATO
2010-01-01
Abstract
A "living mulching system" made up of sludge and earthworms (Eisenia fetida) were tested in a laboratory experiment with the goal of improving the biochemical and chemico-physical properties of two different agricultural soils: a clay soil (Vicarello, Italy) and a sandy-loam soil (Murcia, Spain). A sludge-earthworms mixture was layered onto the soil surface and kept moistened for 4 mo. Biochemical and chemico-physical soil properties were compared in order to assess the efficiency of living mulch as a function of soil type. The experiment showed that soil improvement starts from the activation of the microbiological processes through a gradual modification of the nutritive conditions occurring within the living mulch system due to earthworm activity. Also the physical properties of both soils were improved by increasing the total cracked area, mainly due to the formation of small (< 500 mu m) and small-medium cracks (500-1000 mu m), which represent the typical micro-habitat for soil microorganisms. In fact, in these soils a positive correlation was found between dehydrogenase enzyme activity, total shrinkage area and small-medium size cracks. The improvement of soil structure is of great agronomic relevance in that good physical properties favour water retention, oxygen diffusion and nutrient availability, which combine to improve soil quality and fertility.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
