Deliverable 5.7.Technical report on alternative fertilisers (arable farming and vegetables)

Summary

This Deliverable D5.7 is a ‘Technical report on alternative fertiliser’. It is a shorter version, containing key facts and characteristics about the material investigated and described in the much longer ‘Summary paper of alternative fertilisers’ (Deliverable D5.6), from the Horizon2020 project "Organic-PLUS" (2018-2022). In organic farming, a considerable amount of nutrients and organic matter are derived from conventional farming as fertilisers from organic sources are not available in sufficient quantities, in particular for stockless organic farms or intensive vegetable and fruit production. Furthermore, the EU Regulation on Organic Food and Farming restricts the use of recycling fertilisers from urban sources. Relying on fertilisers from conventional production is a challenge for the integrity of organic production.
The ‘contentious fertilisers’ include animal manure and other animal-derived products such as hydrolysed proteins or keratins from non-organic, conventional, animal husbandry, but also plant-derived products such as vinasse from conventional sugar-beet production. Furthermore, there may be issues with veterinary drugs and pesticide residues in such fertilisers, as shown for liquid vinasse-based fertiliser which contained residues of pyralid, a herbicide used frequently in conventional sugar beet farming (e.g. McKinnon et al. 2021). In addition, the rapidly increasing demand for vegan products and the reduced consumption of meat for environmental reasons contributes to the importance of finding alternatives to animal-derived fertilisers in general. We also addressed other soil-related contentious inputs in Work Package 5 in Organic-PLUS: Within Deliverable 5.1 the current use of peat in growing media, plastic for mulch films and fertilisers in organic agriculture was assessed, followed by a report discussing possible alternatives to these contentious inputs (Deliverable 5.2). The topics of peat in growing media and biodegradable plastic for mulching made from renewable materials have been described in separate deliverables (D5.8; D5.9; D5.10; D5.11).
For alternative fertilisers, several trials have been conducted with funding from Organic-PLUS in five countries: Norway (NORSØK), UK (CU), Denmark (ICOEL), Poland (CUT) and Germany (UHOH). In work package SOIL, Task 5.4 “Examination of promising alternatives, fertilisers” the trials investigated the use of the alternative fertilisers in the open field, protected cropping and in pot trials in organic vegetable production and in arable farming. For some trials, fertiliser effects were assessed for the main crop and the residual effects were tested in subsequent crops. In Task 5.4, we have collaborated to produce two deliverables, D5.6 and 5.7, where D5.6 is a summary paper describing the output of the fertiliser trials. As outlined this deliverable (D5.7) is a technical report describing some essential characteristics of the fertiliser materials which were tested at different locations in Europe and reported in deliverable (5.6).
To structure a scientific discussion about the future fertilisation inorganic agriculture, we have developed three categories to classify the fertilisers applied in Organic-PLUS: URBAN, VEGAN, and RESID:
URBAN fertilisers are defined as materials which contribute to close the rural-urban nutrient and organic matter cycles by recycling resources derived from agricultural land, via urban food systems and back to the land. A relevant example which has been intensively studied in Organic-PLUS is digestate from source-separated organic household waste, which is used for biogas production by anaerobic digestion. These fertilisers are available in several European countries at the level of a municipality.