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What Are The Benefits of Mealworm Frass? (2023)

Updated: May 9, 2023

benefits of mealworm frass cover

Mealworm frass possesses high levels of nitrogen, phosphorus, and potassium, making it ideal for fertilizing crops such as wheat or corn, vegetables, fruits, and grains. In addition, mealworm frass has been shown to possess a wide range of macronutrients, micronutrients, and beneficial microorganisms that can help to improve soil health.

Mealworm frass may be an interesting alternative to "traditional" NPK fertilizers as it is natural and circular. Indeed, mealworm frass is a by-product of mealworm farming, which is known to use organic waste to feed the insects being reared.


The rearing of insects to obtain protein for human food, animal feed, and plant fertilizers has seen tremendous growth in the past years.

Indeed, insect production has sparked the interest of many investors and actors in the food chain, given their high protein levels and much smaller ecological footprint: insect rearing requires less land and water compared to chicken, pig, and cattle farming.

In addition, it has been shown that insects have a lower feed-to-meat conversion ratio. In simple terms, you need far less feed and water to produce 1kg of insects than to produce 1kg of chicken.

Anyway, let’s get on topic here.

This article covers another output of insect rearing: fertilizer. More specifically, we will be discussing the benefits of mealworm frass as a fertilizer for plants and crops.

Where does mealworm frass come from?

During their farming process, mealworms eat, grow, and produce waste. This waste, mealworm faeces, known as “frass” turns out to be very rich in nutrients and has a great potential impact on soil fertility.

Many companies, including world insect production leaders Ynsect, Protix, Tebrio, and Innovafeed – to name a few – are already commercializing frass as fertilizer.

high quality soil

Is mealworm frass of the same quality as “traditional” NPK fertilizers?

First of all, let us define NPK fertilizers: these are products containing high levels of nitrogen (N), phosphorus (P), and potassium (K), three primary macronutrients essential for plant growth.

While these nutrients are essential for plant growth, they do not provide the additional benefits that mealworm frass can offer. Indeed, in addition to having a high NPK value, mealworm frass contains a wider range of macronutrients and micronutrients, as well as beneficial microorganisms that can help to improve soil health.

In addition, mealworm frass is a natural and sustainable fertilizer that is produced from insect waste (the faeces we mentioned earlier).

This makes it a more environmentally friendly option compared to many synthetic NPK fertilizers, which are often made using fossil fuels and other non-renewable resources.

farmed mealworms in a hand

How expensive is mealworm frass compared to “traditional” NPK fertilizers?

Currently, NPK fertilizers tend to be more affordable than other organic fertilizers, including mealworm frass.

As the use of mealworm frass is relatively novel, the demand for it and the levels of production most companies can operate are not always high enough to produce mealworm frass which can compete with NPK from a price standpoint. That being said, the price of mealworm-based fertilizer has been decreasing as the demand for organic fertilizers is on the rise.

Mealworm frass as a long-term investment

Most importantly, insect companies and academics argue that mealworm frass contributes to improving soil health, which in turn leads to more productive plants over time, leading to higher crop yields and ultimately, ROI (return on investment).

In other words, while the price per kilogram may not be in mealworm frass’s favour, you may want to consider the long-term benefits of using mealworm faeces as a natural, nutritive and sustainable fertilizer alternative.

What is the NPK fertilizer ratio of mealworm frass?

The percentage of levels of nitrogen (N), phosphorus (P), and potassium (K) in mealworm frass vary from one producer to the next.

While some companies commercialize mealworm frass with an NPK value of 2-3-2 (2% nitrogen, 3% phosphorus, 2% potassium), others sell mealworm frass with NPK values at 3-1-1, 2-1-2, or 2-2-2.

picture of mealworm

Wrap up

The future of mealworm frass as an organic and sustainable fertilizer seems bright. As the production of insects for food and feed is forecasted to grow in the next 5 years, high quantities of frass are expected to be generated. Many studies, including the ones used as sources for this article, have proved the benefits of using mealworm frass on pot plants and barley for instance.

The challenge will now be for producers to scale their operations to achieve full-price competitiveness and adapt their products to the needs of different crop types.


Houben, D., Daoulas, G., & Dulaurent, A. M. (2021). Assessment of the short-term fertilizer potential of mealworm frass using a pot experiment. Frontiers in Sustainable Food Systems, 5, 714596.

Houben, D., Daoulas, G., Faucon, M. P., & Dulaurent, A. M. (2020). Potential use of mealworm frass as a fertilizer: Impact on crop growth and soil properties. Scientific Reports, 10(1), 4659.


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