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Soil fertility status and nutrient input–output flows of specialised organic cropping systems: a review | SpringerLink
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![Heinz-Christian FRÜND | Hochschule Osnabrück, Osnabrück | Faculty of Agricultural Sciences and Landscape Architecture Heinz-Christian FRÜND | Hochschule Osnabrück, Osnabrück | Faculty of Agricultural Sciences and Landscape Architecture](https://www.researchgate.net/profile/Heinz-Christian-Fruend/publication/225100092/figure/fig2/AS:349414859264012@1460318402930/Abb-3-Anzahl-von-Middens-Eingangsoeffnungen-der-Roehren-anecischer-Regenwuermer-in-den_Q320.jpg)
Heinz-Christian FRÜND | Hochschule Osnabrück, Osnabrück | Faculty of Agricultural Sciences and Landscape Architecture
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The challenge of imbalanced nutrient flows in organic farming systems: A study of organic greenhouses in Southern Germany - ScienceDirect
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The challenge of imbalanced nutrient flows in organic farming systems: A study of organic greenhouses in Southern Germany - ScienceDirect
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