Research & Practice
This page summarises European research comparing bio-based nutrient materials (like Soil Synergy) compared with processed organic fertilisers such as poultry manure pellets. All figures shown are ranges observed across multiple independent field trials, not best-case values.
The purpose of this page is to explain observed agronomic differences under practical farming conditions, based on independent research.
1. Mineralisation & Nitrogen
Interpretation
Independent studies consistently show that bio-based nutrient materials achieve 10–30 percentage points higher first-year nitrogen efficiency compared to pelletised organic fertilisers.
These differences are most pronounced in crops with:
early nitrogen demand
rapid vegetative growth
Underlying mechanism
Pelletised organic fertilisers contain a higher proportion of organically bound nitrogen, resulting in slower mineralisation and partial immobilisation during the first growing season.
Bio-based nutrient materials contain a higher share of plant-available ammonium-N (NH₄⁺), enabling faster uptake and improved synchronisation with crop demand
2. Crop Yield Performance
Observed across multiple crop groups
Cereals
Maize
Forage crops
Horticultural crops
Interpretation
No structural yield penalty is observed for bio-based nutrient materials.
In several cases, yields are equal or up to ~10 % higher, mainly due to improved nitrogen efficiency
Pelletised organic fertilisers may show stronger residual effects, but these typically do not translate into higher first-year yields.
3. Soil Biology
When bio-based nutrient materials and pelletised organic fertilisers are applied at comparable organic matter rates per hectare, independent research shows consistent differences in short-term microbial response.
Interpretation
Bio-based nutrient materials tend to trigger faster microbial activation, driven by:
higher proportions of soluble carbon fractions
readily available ammonium-N
Pelletised organic fertilisers show a slower but more gradual microbial response.
These differences primarily affect nutrient cycling speed, not total organic matter accumulation.
4. Agronomic implication
Independent European research shows that when organic matter input per hectare is aligned, bio-based nutrient materials and pelletised organic fertilisers differ primarily in nutrient timing and release dynamics, not in total organic matter contribution.
Bio-based nutrient materials tend to drive faster nutrient cycling and higher nitrogen efficiency, while pelletised organic fertilisers mainly influence the gradual release of nutrients over time rather than immediate availability. Separating nutrient delivery from release speed therefore enables more precise fertilisation strategies under practical farming conditions.
Product-specific trials to further quantify these effects are ongoing.
Sources
Möller, K. & Müller, T. (2012). Effects of anaerobic digestion on digestate nutrient availability and crop growth.
Engineering in Life Sciences.Gutser, R. et al. (2005). Short-term and residual availability of nitrogen after long-term application of organic fertilizers.
Journal of Plant Nutrition and Soil Science.Sigurnjak, I. et al. (2017). Fertilizer performance of liquid fraction of digestate as synthetic nitrogen substitute in maize cultivation for three consecutive years.
Science of the Total Environment.Alburquerque, J.A. et al. (2012). Agricultural use of digestate for horticultural crop production and improvement of soil properties.
European Journal of Agronomy.Reuland, G. et al. (2022). Assessment of the Carbon and Nitrogen Mineralisation of Digestates Elaborated from Distinct Feedstock Profiles.
Agronomy.Insam, H., Gómez-Brandón, M. & Ascher, J. (2015). Manure-based biogas fermentation residues – friend or foe of soil fertility?
Soil Biology & Biochemistry.
Related Comparisons
Poultry manure pellets account for the majority of the organic fertiliser market and therefore serve as the market reference.
To ensure a reasonable and honest comparison, this analysis relies solely on data, figures and independent research rather than opinions or reviews.
Further agronomic and trace-element comparisons are provided in the sections below.
