Robert Mwangi (L), founder of Nawiri organics that produces and distributes organic fertiliser, inspect the progress of mature Black soldier fly (BSF) pupae harvested from troughs of organic food waste with one of his workers at their BSF farm in Njoro constituency, Nakuru county on July 30, 2026. Agriculture is vital to East Africa's economy, but a 2025 soil report by German NGO Heinrich Boll Foundation found that more than 40 percent of the region's soils were degraded -- in part by overuse of chemical fertilisers -- costing more than $65 billion a year in lost productivity. Fertiliser prices have also increased this year due to the war in the Middle East, driving a search for alternatives. In Kenya, 32 percent of cropland was classified as strongly acidic in the soil report. Changing climatic conditions and overly intensive farming practices are among the causes, but Muturi says moving away from chemical fertilisers has boosted his harvests at his farm in Lari, about 50 kilometres from the capital, Nairobi. (Photo by Tony KARUMBA / AFP via Getty Images)