EFFECT OF GROUNDCOVER ON AVAILABLE MACRONUTRIENT CONTENT OF SOIL AND PLANT UPTAKE IN NON-BEARING PEAR ORCHARD

The impacts of different groundcover materials on soil nutrient availability and nutrient uptake of trees in non-bearing pear (Pyrus sativa) orchard in east Hungary were investigated from 2006 to 2008. Trees of the pear cultivar ‘Vilmos’ grafted on quince rootstock were planted into a lowland chernozem soil in 2003. The mulches were placed on the ground with 0.75 m wide edges buried in the soil on both sides of a tree row. Applied treatments were: pine bark mulch, straw, straw plus cow manure, cow manure and as a check: control treatment without any mulch application. Soil samples were taken at the beginning of the study in April and after defoliation in November (2006) and it was repeated in 2008. Leaf samples were taken every August in the studied period. It was found that manure containing treatments slightly increased the easily soluble nitrogen forms, phosphorus and potassium content of soil. Furthermore, the manure containing treatments increased the N and P content of the leaf, while the applied treatments induced decreases of leaf K. In addition, our results suggest that leaf nutrient concentrations respond differentially to different mulches. Our results indicate that groundcover management is a useful tool to satisfy the demand of trees because it improves the availability of soil nutrients, reduces weed competition and results harmonized nutrient ratios in leaves.