Practice Abstract - Research and innovation

Green fertilizers: Lucerne and clover pellets for winter wheat

There is a growing need for research into alternative fertilization methods in grain cultivation. Conventional farming typically uses a combination of synthetic fertilizer and a second application of slurry. In organic farming, fully animal-based fertilizers are more commonly used. The challenges differ between the two systems. Organic farming already relies largely on circular fertilizers, but the availability of animal manure is limited, creating a demand for alternative sources. In conventional farming, linear (non-renewable) fertilizers are still widely used, accounting for about 50% of total fertilizer input. The key challenge here is reducing dependence on these inputs. Fertilizer price shave risen sharply in recent years, and concerns about nutrient leaching into surface water are becoming increasingly urgent. A potential solution for both systems could be increased use of plant-based fertilizers, such as alfalfa or grass pellets.

The use of plant-based fertilizers offers a major opportunity to reduce chemical fertilizer use in conventional farming. Additionally, it can help lower the use of animal manure in both conventional and organic grain cultivation. By introducing this third fertilization option, farmers become less dependent on synthetic and/or animal-based fertilizers. The use of more natural products is also expected to improve soil biodiversity, which in turn supports better soil health. 

Grain farming often operates on tight margins, so rising fertilizer costs can have a significant impact on profitability. At the same time, the Netherlands faces a pressing challenge to improve water quality, an issue in which the agricultural sector plays a key role. Regulations on fertilizer use are becoming increasingly strict. The need to maintain yields while also improving water quality is urgent. Using plant-based fertilizers to help prevent nutrient leaching is a practical and forward-looking solution that fits well within the operations of many farms. 

Additional information

We are testing whether the standard fertilization in both organic and conventional winter wheat cultivation can be fully or partially replaced by alfalfa and/or grass pellets. We are examining different application rates and timings. Soil samples are taken from the fields before and after the growing season to measure how much nitrogen and other nutrients remain in the soil. Throughout the season, crop development is monitored, focusing on plant growth, common diseases, ripening, and lodging. At the end of the season, yield and grain quality are assessed, including moisture content, protein level, Zeleny index, hectoliter weight, and starch content. The pellets used in the trials have been analyzed beforehand for their nutrient composition, which determines the appropriate application rate.

Each year, the different treatments are compared. After four years of research, we aim to provide a well-founded recommendation on the advantages and disadvantages of using plant-based pellets compared to current standard fertilization practices in both organic and conventional winter wheat farming.

Challenges

  • Evaluating how Lucerne and grass pellets perform compared to conventional fertilizers in terms of yield and nutrient availability
  • Reducing reliance on synthetic fertilizers
  • Identifying the tangible agronomic benefits of using Lucerne and grass pellets on different soil types and crop systems
  • Understanding the residual effects of Lucerne and grass pellets on subsequent crops, including cover crops and main crops
  • Assessing whether plant-based fertilizers contribute to increased weed pressure in the field
  • Determining the impact of plant-based fertilizers like grass-clover on soil biological activity and soil health

Resources 

  • Sufficient availability of plant-based alfalfa and/or grass pellets
  • Possibility to apply the pellets early in the season onto the crop
  • Knowledge of soil nutrient levels through soil sampling, in order to determine the correct fertilization dosage.
Source Project
Transformation for sustainable nutrient supply and management
Ongoing | 2022-2026
Main funding source
Horizon Europe (EU Research and Innovation Programme)
Geographical location
Denmark, Germany, Hungary, Netherlands, Romania, Switzerland, The United Kingdom, China
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