Organic fertilizers in fruit orchards (Biofruitnet Practice Abstract)

Summary in the original language of the document

Alternating and integrating different fertilizers, depending on the nutrient budget and the soil status of plant available nutrients, can lead to a more balanced nutrient input.
Practical recommendations. When planning to use organic fertilizers consider alternative recommended fertilizers:
1) Clover-grass pellets or silage, from on-farm sources (preferred) or external sources; 2) Waste materials (e.g., biogas digestate, residues from yeast production, household wastes); 3) External fertilizers locally available (e.g., composts or extracts)
New fertilization strategies must be developed: 1) The mineralization rate of the products: liquid fertilizers, stillage, biogas digestate - mineralize rapidly and thus when applied in spring N supply matches well with fruit tree N demand, while compost materials have a very low N availability (< 10%) in the year of application; 2) Site specific features (e.g., cropping system, management practices, soil type, climate).
When searching for alternative fertilizers: 1) Compatibility with existing farm machinery; 2) Production costs, including labor and machinery costs (e.g., for clover-grass silage produced by the farmer) 3) Acceptance by certification bodies or additional quality schemes (e.g., from retailers) and potential contaminations (in case of waste derived fertilizers)