The Impact of Conservative Soil Maintenance Practices in Vineyards on Soil Microbial Diversity and on the Biodiversity of Useful and Harmful Entomofauna

In the context of actual climatic changes, which led to an increase of soil hydric stress, new agrotechnical solutions were experimented to ensure a moisture preservation in soil and the conservation of soil microbial activity. These included the use of mulching systems and the cover crops, in order to replace the use of the classical black furrow system. In this respect, the aim of our study was to evaluate the influence of the use of soil mulching systems and of the cover crops in vineyards on the microbial biodiversity of the soil and on the biodiversity of the useful and harmful entomofauna, in comparison with the classical maintenance system, represented by black furrow. The researches were performed during two particularly dry years in two experimental plots located in Valea Cǎlugǎrescǎ viticultural center. In one of them were experimented, as soil maintenance systems, the total straw mulching and the partial mulching (interval between rows) with marc compost, in the other the artificial grassing of the interval between rows with ornamental clover Nano and with honey plants represented by Melilotus officinalis. The experimental data have shown the positive effect of mulching systems on soil microbial activity, highlighted by an increase of soil microbial load and of its diversity (represented by bacteria, fungi, algae and protozoa), especially in case of mulching with marc compost (15.94 million microorganisms/g of soil, as compared with 5.9 million in case of black furrow system). Also, the ratio between fungi and bacteria was higher in case of partial mulching, this aspect being a favorable factor for soil biological activity. The use of cover crops indicated a positive effect in the increasing of useful entomofauna, belonging to the orders Ortoptera, Coleoptera and Arahnidae (especially in case of the artificial grassing).