Effects of biowaste compost on vegetative growth, Yield and fruit quality of james grieve apples
In Lower Austria 69 agricultural composting plants are in operation in addition to municipal and commercial composting plants. The agricultural composting plants process separately collected organic household waste as contractual partners for the neighbouring municipalities. The compost produced is used to a large extent on the agricultural fields of the plants' owners. In order to improve the compost quality and to open up new markets for biowaste compost the EU project Art. 8 n° AU-95-0256 was initiated. In the framework of this project several compost application trials - in a vineyard, in a tree nursery, in horticultural potting media, in a Christmas tree plantation and in an apple orchard - were set up.
Orchards are well suited for fertilisation with compost because fruit trees take up nutrients during a very long period of the year and their nitrogen requirement is much lower than that of field crops (Dierend et al., 1996) so that, depending on the humus content of the soil and on the conditions for mineralisation, the N-mineralisation from the organic matter of the soil may be sufficient to satisfy the N-requirement of fruit trees. This trial was initiated to assess the effects of compost fertilisation on growth and yield of apple trees and on the soil conditions in the orchard.