Einfluss der Düngung mit Gärrückständen aus der Biogaserzeugung auf den Ertrag von Silomais und auf die bodenmikrobielle Aktivität

Summary

Organic manuring with slurry from biogas plants may contribute to plant nutrition and maintenance of soil fertility in organic farming. However, the chemical properties of biogas slurry depend markedly on substrate input and process technology. The aim of this study was to gain more insights into the relationship between the quality of biogas slurry and its influences on plant and soil parameters when applied as organic ma-nure. We studied the effects of slurries from two different biogas plants on yield of maize and soil microbial activity in a two-year field experiment. The investigation took place on a loam-clay soil near Göttingen, Lower Saxony. Biogas slurry A was obtained from a biogas plant with liquid pig manure as main input, slurry B originated from a biogas plant operated with renewable primary products. Slurries were applied as 30 and 60 m3 ha-1 respectively. Highest yield of maize was obtained in the treatment with slurry B when given as 60 m3 ha-1. N content in biomass of maize was the highest in the treatment with slurry A (60 m3 ha-1). β-glucosidase activity was not affected by any of the slurries. Conversely, both slurries were found to significantly increase dehydro-genase activity as well as total soil C and N contents.