Âé¶¹ÒùÔº


No waste left behind: Insect droppings can improve soil fertility

No waste left behind: Insect frass can improve soil fertility
Frass fertilizer in circular agroecosystems. Rearing insects on food waste and land-applying frass on forage and crop systems can allow for the sustainable intensification needed to feed a growing population. This study paves the way for field studies using frass, and identifies research gaps that need to be filled to allow the widespread use and valorization of this disruptive fertilizer. Credit: Scientific Reports (2025). DOI: 10.1038/s41598-025-87075-8

Insect droppings, commonly known as insect frass, may seem useless and downright disgusting, but scientists found that this waste can improve soil health when added as a fertilizer in farming.

Insect frass is a mixture of excreta, feed, and molted skins. These droppings are a by-product of farming insects like yellow mealworms, banded crickets, and black soldier flies. Farmers raise and breed insects, also known as "mini-livestock," to be an alternative protein source for animals and be a more sustainable practice in agriculture.

Insect frass may also be used as fertilizer. Previous studies by this team led by the United States Department of Agriculture (USDA)'s Agricultural Research Service (ARS) show insect frass can have higher carbon and nitrogen content than fossil fuel-based fertilizers and fewer pathogens than other animal manures.

These researchers, along with collaborators from the University of Arkansas System Division of Agriculture, also studied insect frass' potential as an organic source when used as a in farming. The study is in the journal Scientific Reports.

In a two-year field study, researchers found that frass from yellow mealworm increased the amount of carbon by two times and nitrogen by three times in soils than other sources like poultry litter and ammonium nitrate. Furthermore, soils with frass addition produced and carbon dioxide emission rates similar to soils amended with poultry litter and ammonium nitrate.

No waste left behind: Insect frass can improve soil fertility
Insect frass. Credit: Taylor Adams, ARS

"Insect frass substantially improved which showed its ability to be used as an alternative to inorganic fertilizers," Amanda Ashworth, a soil scientist at the ARS Poultry Production and Product Safety Research Unit in Fayetteville, Arkansas, said.

"This is important since insect farming is on the rise and circular agricultural systems (agricultural by-products that are recycled back into ) can be sustainable avenues for growing foods in the future."

According to Meticulous Research's Global Edible Insects Market Forecast to 2030 report, the insect farming industry is expanding in response to increasing demands for sustainable protein sources for animal feed. The industry is projected to grow 28% annually and have an estimated market value of $8 billion U.S. dollars by 2030.

More information: Amanda J. Ashworth et al, Insect frass fertilizer as soil amendment for improved forage and soil health in circular systems, Scientific Reports (2025).

Journal information: Scientific Reports

Citation: No waste left behind: Insect droppings can improve soil fertility (2025, January 29) retrieved 3 July 2025 from /news/2025-01-left-insect-soil-fertility.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Explore further

Insect frass becomes food for protein-rich microalgae

27 shares

Feedback to editors