Efficient strategies for using composts in agriculture demand for parameters to estimate their nitrogen effect (mineralization, immobilization) in soil. To find such a parameter different extraction methods (water extract, K2S04 extract, hot water extract) were carried out on 81 different biogenic waste composts. Besides this selfheating capacity, total organic carbon and total nitrogen were determined. The results of compost analysis were correlated with nitrogen uptake by oat in two pot trials. Selfheating capacity did not correlate with the nitrogen effect of the composts. The C/N ratio of the solid phase of composts was considerably well related to N uptake by oat and is therefore an important quality criterion of composts. But the correlation was found to depend on the similarity of law materials and management of composting. All in all the best correlation to N uptake by plants was given by the total organic carbon to total nitrogen ratio of K2SO4 extracts (C/NK2SO4). The correlation coefficients were almost the same in both pot trials. C/NK2SO4 is therefore proposed to be a good parameter to estimate the nitrogen effect of composts. This is further supported by results from field trials.
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- Parameters to Estimate the Nitrogen Effect of Biogenic Waste Composts
- Springer Netherlands