Crop rotation with plant residues returned as biodigestate
Project manager: Gunnar Svensson, Dept of Crop Science, SLU.
Project group: Ulla Gertsson and Anita Gunnarsson, Hortikultur, SLU
The aim of the project is to achieve nutrient supply within a five-year crop rotation through including a green manure crop and returning residues from the commercial crop and the green manure in the form of biodigestate. The crop rotation includes the following crops:
- Green manure
- Spring wheat
- Spring barley with undersown crop
The advantages of this system are that:
- Plant nutrients can be saved from one season to the next and can therefore be used at the desired time in the next season.
- Nitrogen fixation in the green manure is probably increased, since the cut biomass is removed
- The biodigestate is liquid and can therefore be used in the growing crop
- Biogas is produced as a by-product.
The beetroot crop is in a separate treatment with different pre-crop treatments and associated quality studies. To this part of the project Anita Gunnarsson is associated as a PhD-student.
Gunnarsson, A., Gertsson, U. and Bohn, L. 2006. Anaerobically digested crop material for improved nitrogen efficiency in a crop rotation with beetroot (Beta vulgaris var. Conditiva alef.). Acta Horticulturae700, 267-270.
Gunnarsson A., Lindén, B. and Gertsson, U. 2008. Residual nitrogen effects in organically cultivated beetroot following a harvested/green manured grass-clover ley. Journal of Plant Nutrition 31(8), 1355-1381. DOI: 10.1080/01904160802206190