
Sustainable agriculture is booming, and with it, increased attention is turning to innovative solutions such as frass, a revolutionary organic fertilizer produced from insect droppings. Known for its exceptional nutritional properties and its positive environmental impact, Frass is positioned as a promising alternative to conventional chemical fertilizers.
According to the definition of the 2021 EU regulation, frass is a mixture of livestock insect excrement, food substrate, insect parts and dead eggs, with a dead insect content of no more than 5% by volume and 3% by weight. These insects convert organic matter into a fertilizer that is rich in essential nutrients such as nitrogen, phosphorus, potassium, calcium, and magnesium. It is a natural source of fertilization that not only helps to nourish the plants but also to improve the overall health of the soil.
Complete Plant Nutrition : Frass provides a comprehensive range of essential nutrients to support crop growth and development in a balanced and sustainable manner.
Improving Soil Structure : By enriching the soil, frass increases its ability to retain water and allow better root infiltration, thus promoting robust root growth and better nutrient absorption.
Stimulation of Microbial Life : The microorganisms found in frass enrich the soil and promote beneficial microbial biodiversity, contributing to the long-term health of the soil.
Recent research has highlighted the significant benefits of frass on various types of crops:
Cereals (especially maize): Studies have shown that the use of frass from black soldier fly larvae (BSF) leads to notable increases in yield. A study compared the performance of BSF frass with that of a commercial organic fertilizer on maize production (H513). Both fertilizers were applied at doses of 0, 2, 5 and 7.5 tons per hectare, as well as 0, 30, 60 and 100 kg of nitrogen per hectare. A mineral fertilizer (urea) was also applied at the same doses to establish the nitrogen equivalence (NFE) of organic fertilizers.
The results were impressive:
- Maize grown on plots treated with BSF frass showed taller plants and a higher chlorophyll concentration.
- Plots treated with 7.5 tons per hectare of BSF frass had 14% higher grain yields than those treated with an equivalent quantity of commercial fertilizer.
- There was a 27% and 7% increase in grain yields in plots treated with 100 kg of nitrogen per hectare of BSF frass compared to those treated with equivalent doses of commercial fertilizer and urea, respectively.
- The application of BSF frass at 7.5 tons per hectare significantly increased nitrogen uptake by up to 23% compared to the equivalent rate of commercial fertilizer.
- The application of frass to 100 kg of nitrogen per hectare increased maize nitrogen uptake by 76% and 29% compared to commercial fertilizer and urea, respectively.
- Maize treated with 2.5 tons per hectare and 30 kg of nitrogen per hectare of frass showed higher nitrogen recovery efficiencies compared to equivalent levels of commercial fertilizer.
- The agronomic efficiency of the use of nitrogen (AEN) of maize treated with 2.5 tons per hectare of BSF frass was 2.4 times greater than that obtained with an equivalent quantity of commercial fertilizer.
- The NEA of maize grown with 30 kg of nitrogen per hectare was 27% and 116% higher than the values obtained with equivalent levels of commercial fertilizer and urea, respectively.
- BSF's application rates of 2.5 tons per hectare and 30 kg of nitrogen per hectare of frass from BSF were effective in improving maize yield, while double doses of commercial fertilizer were required.
Vegetables (such as tomatoes): According to a study published in the Journal of Economic Entomology in 2023, the use of frass led to more vigorous plant growth and more abundant fruit production. Tomatoes grown with Frass showed a significant increase in size and number of fruits compared to conventional fertilization methods.
Leaves (such as lettuce): Improvements in leaf quality and increased crop weight were documented in Frontiers in Sustainable Food Systems in May 2024. Studies show that insect frass has diverse and positive effects on leafy vegetable production:
- The nutrient profile of the compost used is crucial in determining the results of the plants.
- The addition of black soldier fly larvae (BSF) frass improves the nutritional quality of arugula and lettuce.
- Lettuce, in particular, which is a more domesticated crop, responds very favorably to treatments in terms of productivity and greenery.
- Arugula seems to benefit more in terms of micronutrients thanks to the incorporation of BSF.
- Leafy vegetables are essential crops grown all over the world. Increasing the sustainability of their production contributes to making fresh, nutrient-rich foods more accessible.
- Practices aimed at improving the long-term environmental results of controlled environment agriculture can offer sustainable production solutions.
- For producers wishing to adopt insect frass in their potting soil mixtures, it is recommended to start by replacing the peat with 10% frass by volume.
Ornamental plants: A study published in the International Journal of Environmental Research and Public Health in January 2023 found an increase in the number of flowers and better pest resistance through the use of frass. In a recent study, frass was shown to be a potentially valuable and safe source of nutrients, especially nitrogen, for plants. The recommended levels of mineral nitrogen in a horticultural substrate for the production of vegetables and ornamental plants were not exceeded in treatments with high levels of frass (200 and 400 mg N dm³), indicating that organic nitrogen was mineralized at a moderate rate and that nitrogen losses were minimized. However, due to periodic increases in soil salinity, a nitrogen level of 400 mgdm³ is not recommended for plants grown from seed. In contrast, a frass level of around 10 g dm³ of substrate (400 mg N dm³) provides optimal quantities of bioavailable nitrogen, phosphorus and potassium for plants grown from seedlings. In addition, high levels of FRASS (5 and 10 g dm³) increase the abundance of the microbiota responsible for the decomposition of organic matter. Unlike frass, urea increases the number of nitrogen-fixing bacteria in peat. These results can be used in large-scale plant growth experiments. With the increasing popularity of insect farms, frass is becoming increasingly available and could be a promising and environmentally friendly alternative to conventional fertilizers in the near future.
Compared to traditional chemical fertilizers, frass has several distinct advantages:
Sustainability : As a natural and renewable product, frass reduces the carbon footprint of agriculture while providing essential nutrients to plants.
Environmental safety : Being free of synthetic chemicals, frass does not pollute soils or groundwater, maintaining the health of local ecosystems.
Continuous Soil Improvement : By nourishing the soil and improving its natural fertility, frass contributes to maintaining healthy and productive agricultural land over the long term.
In summary, frass is much more than just a fertilizer; it is a holistic solution to promote sustainable and environmentally friendly agriculture. By promoting robust crop growth while maintaining soil fertility, frass offers farmers an effective and responsible alternative to traditional methods. By adopting frass, we are not only improving agricultural yields, but we are also contributing to the preservation of our planet for future generations. Make the decision today and invest in a greener and more prosperous agricultural future.