Comparative earthworm research in various ecosystems with different anthropic impact

Abstract

Using pedofauna research in the integrated agro-ecological monitoring is a necessary perspective, considering that some populations, such as earthworms, characterize the potential soil fertility, health quality and vitality, providing thus ecological stability. Research of pedofauna with positive role for soil fertility allows to monitor the vitality and activity of soil biota and to avoid the critical levels. The present research was conducted in long term field experiments (41 years), in crop rotation, and in monoculture (55 years) at the Didactic Experimental Station "Chetrosu" of the State Agrarian University of Moldova, from Chisinau, Republic of Moldova. Earthworms’ numerical research was performed in six different crop agroecosystems, forest strip and in the Scientific Reserve "Codrii". There were investigated the morphological and physicalchemical features of the soil, which was diagnosed as chernozem (FAO System). Earthworms have been collected in soil samples by 0,25 m2, in 8 repetitions, removing the soil up to 40 cm depth, in layers of 10 cm and further quantitative measurements (number, weight, abundance) were made. Also, the formaldehyde method of earthworm extraction from soil was used (ISO 23611-1/2006). According to research results, the earthworm density in the soil of different field agro-ecosystems can be arranged in the following decreasing range: fallow, alfalfa, wheat, corn, sun-flower, peas. As concerning the distribution by depth horizons, was found a larger earthworm number in the tillage soil, in the horizons with humus, roots and plant debris totally or partially decayed.