Occurrence of mites (Acari) in the soil of a blackcurrant plantation after applications of organic mulches and mycorrhizal inoculum

The study was conducted in the Pomological Orchard of the Research Institute of Horticulture in Skierniewice on a plantation of blackcurrant cultivar ‘Tiben’. The following variants of the experiment were applied: control – NPK fertilization only, mulching with a peat substrate, shredded pine bark, sawdust of coniferous trees, bovine manure, plant compost, straw of cereals, and application of mycorrhizal inoculant MYKOFLOR. Mulching was performed each year in the spring in an amount of 25 dm3 per plot, and the inoculum was applied in an amount of 10 ml per shrub. Samples for acarological examinations were collected at 4 times, in the spring and autumn of successive seasons in 2012-2013. An increase in the overall density of mites, in comparison with the control surface, was observed after mulching the soil with sawdust of coniferous trees and plant compost. On all the plots, the communities of mites were dominated by mites of the order oribatid mites. For these mites, a statistically significant increase density was recorded after mulching the soil with sawdust of coniferous trees, bovine manure and plant compost. Mulching did not increase significantly the species diversity of oribatid mites. The soil of the blackcurrant plantation was found to be inhabited by relatively large numbers of two common oribatid mites species: Punctoribates punctum and Tectocepheus velatus. An increase in the population density of Punctoribates punctum was observed after mulching with peat, sawdust and compost.