A team of international scientists has found a practical and affordable way to reduce locust damage to crops, offering fresh hope to farmers who have long struggled against these destructive pests. The breakthrough study, led by researchers associated with Arizona State University, shows that improving soil nutrition can dramatically cut locust numbers, reduce crop damage and even double yields under real-world farming conditions.
Locust swarms, often compared to biblical plagues, continue to devastate crops across large regions, wiping out livelihoods and worsening food insecurity. Swarms can stretch across hundreds of square kilometres, consuming nearly every green plant in their path. While chemical pesticides have traditionally been used to control outbreaks, they are costly, environmentally harmful and often inaccessible to small farmers.
The new research marks the first time a soil-based intervention has been tested directly on working farms and proven effective.
On How Changing Soil Nutrition Weakens Locusts
The study builds on more than a decade of research into locust biology and behaviour. Scientists found that plants grown in nutrient-poor soil tend to be high in carbohydrates and low in protein, creating an ideal “energy-rich” diet for locusts that fuels population growth and mass migration. This carbohydrate-heavy diet helps locusts survive long-distance swarming and increases their destructive potential.
By contrast, plants grown in nitrogen-rich soil contain more protein and fewer carbohydrates. Such plants are difficult for locusts to digest and do not provide the energy they need to swarm. The research team set out to test whether improving soil quality could change plant nutrition enough to disrupt locust feeding and reproduction.
To do this, researchers partnered with 100 farmers in two villages in Senegal, where outbreaks of the Senegalese grasshopper regularly threaten food security. Each farmer planted two millet plots, one treated with nitrogen-rich fertilizer and one left untreated. Over the growing season, scientists monitored locust presence, crop damage and final yields.
The results were striking. Fields treated with nitrogen showed significantly fewer locusts, much lower crop damage and nearly double the harvest compared to untreated plots. Importantly, the researchers found no evidence that improving soil nutrition attracted other pests or created new agricultural problems.
Onwards to Sustainable, Farmer-Led Solutions
While chemical fertilizer was used for the experiment, the researchers emphasised that long-term success depends on affordable and environmentally friendly alternatives. Follow-up work has shown that composting crop residues can deliver similar results by naturally increasing nitrogen levels in the soil.
Encouraged by the findings, farmers involved in the study have already changed their practices. Instead of burning crop waste after harvest, many are now composting residues to fertilise their fields. This shift not only improves soil health and crop productivity but also helps reduce locust and grasshopper infestations without relying on pesticides.
Despite the cancellation of project funding in early 2025, local communities in Senegal have continued using the compost-based approach independently. Researchers are now seeking new funding to expand the method to other regions affected by locust outbreaks.
Scientists believe the discovery could reshape how the world manages locusts, moving away from reactive chemical control toward preventive, nature-based solutions. By understanding how soil, plants and insects interact, farmers may finally gain a sustainable tool to protect crops, strengthen food security and stay one step ahead of one of agriculture’s oldest threats.