ISHS Acta Horticulturae 700: International Symposium Towards Ecologically Sound Fertilisation Strategies for Field Vegetable Production
ANAEROBICALLY DIGESTED CROP MATERIAL FOR IMPROVED NITROGEN EFFICIENCY IN A CROP ROTATION WITH BEETROOT (BETA VULGARIS VAR. CONDITIVA ALEF.) |
| Authors: | A. Gunnarsson, U. Gertsson, L. Bohn |
| Keywords: | biogas, fermentation, green manure, mixed ley, organic farming, fertilization |
| Abstract:
A common practice in organic farming when ruminants are not present is to leave beet leaves and biomass from green manure leys in the field for their residual fertility effect. A two-year field experiment was conducted to evaluate whether the use of N could be improved by processing beet leaves and biomass from temporary grass/clover ley in a biogas reactor and using the effluent as a fertilizer compared to general practice. The first year included barley and mixed ley. The ley was either cut and left on ground for green manure purposes or harvested for biogas production. In the second year, beetroot was grown with a supply of different amounts of effluent. Preliminary results indicate that the crop rotation in which crop material was processed in a biogas reactor and effluent used as a fertilizer had a net increase of N yield of 29 kg N and a net increase of marketable beet root yield of 7 t from processing one ha of ley and one ha of beet leaves. The biogas system also seemed to reduce the variation in beet yield within the field compared to a system with only green manure as the N fertilizer. The experiment will be repeated. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
