Title : Field study of development and agronomic evaluation of a fortified blended organic fertilizer from municipal waste resources for maize production in Malawi
Abstract:
Malawi’s agricultural sector faces a dual challenge: smallholder farmers cannot afford imported synthetic fertilizers, while urban centres struggle with mounting organic waste. This field study developed and evaluated a low-cost fortified blended fertilizer (FBF) produced from locally available waste streams sanitized sewage sludge, wood ash, agricultural lime, and processed human urine supplemented with small amounts of commercial NPK and urea. A randomized complete block design with three replications was established at two contrasting sites in Malawi (Chitipa and Zomba) during the 2024-2025 cropping season. Three treatments were compared: T1 (unfertilized control), T2 (FBF basal plus top-dressing), and T3 (standard inorganic fertilizer at 100 kg/ha NPK + 50 kg/ha urea). Post-application soil analysis showed that FBF substantially raised nutrient levels (N: 308-359 mg/kg; P: 432-503 mg/kg; K: 988-1150 mg/kg), with a composite fertility index of 3397–3953 mg/kg. Maize grown with FBF showed vigorous growth without deficiency or toxicity symptoms, producing an average yield of 3.2 t/ha a 78% improvement over the control (1.8 t/ha) and 82% of the yield obtained with conventional inorganic fertilizer (4.0 t/ha). Soil pH remained slightly acidic (5.7-6.1), and electrical conductivity was elevated. These findings suggest that waste-derived fortified fertilizers offer a viable, sustainable, and affordable alternative to imported synthetic inputs, supporting circular economy principles and improving food security in Malawi.
Keywords: fortified blended fertilizer, waste valorisation, circular agriculture, soil fertility, food security
