Mexican experts revalue nopal waste as fertilizer to restore soils

Researchers in Mexico are finding an innovative use for nopal cactus waste, turning prickly parts and trimmings into a valuable organic fertilizer. This development holds significant promise for restoring degraded agricultural soils, particularly in the Mexico City area. According to the National Autonomous University of Mexico (UNAM), processing nopal waste through anaerobic digestion creates an organic fertilizer that boosts crop biomass by as much as 20%. Crucially, it helps revive biological functions in soils that have been exposed to harmful agrochemicals. UNAM research indicates this organic approach yields more efficient results compared to conventional fertilization methods. The focus of this research is Milpa Alta, a district within Mexico City that is central to the country's nopal production, cultivating nearly 4,500 hectares and supplying over 90% of the capital's demand. The project, supported by the Mexico City Secretariat of Education, Science, Technology, and Innovation from 2018 to 2020, aims to establish sustainable practices for volcanic soils in southern Mexico City. Led by Bruno Chávez Vergara from UNAM's Department of Environmental and Soil Sciences, the initiative seeks to enhance sustainable food production, water recharge, and climate change mitigation. Researchers are collaborating with local farmers and a company called Sustentabilidad en Energía y Medio Ambiente (Suema) to transition from synthetic to organic fertilization and explore the potential of the fertilizer's liquid byproduct, known as digestate.