Injektionstechnik für Düngung und Pflanzenschutz

In natural ecosystems the soil is usually covered with a layer of organic residues that yields several benefits on moisture retention, erosion control, soil biological activity and nutrient cycling. When using plant residues as mulch and to fertilize crops silage can be used to synchronize periods of shortage and availability of clover-grass but little is known about the decomposition patterns of ensiled material and its effects on plants, the soil and the microbial community. In a field experiment, we applied fresh and ensiled clover-grass in a potato field and analyzed the effect on yield, infection by Phytophthora infestans, microbial biomass and the potential activity of soil exoenzymes of the C / and P-cycle. The yield of the plots treated with silage tended to be higher than the unmulched control. Fresh mulch was probably applied in too high quantities( resulting in depressed yields. As the dry climate was unfavourable for P. infestans, no effect on Late Blight infection could be detected. The moisture preserving properties of a mulch layer could be demonstrated but the soil pH was not affected. The microbial biomass was very large even before mulch application and only the silage mulch was able to maintain the initial level. The potential activities of several of the analyzed enzymes ß- glucosidase ß-Xylosidase and peroxidase, as well as N-acetylglucosaminidase and potential nitrification were generally increased with mulching