Valorisation of Kitchen and Garden Wastes to Improve the Fertility of Sandy Loam Soils

In developing countries, the organic fraction of municipal solid waste (OFMSW) makes up the largest proportion of the municipal solid waste. The common practice of landfilling results in high environmental impact. Home composting offers an alternative to landfilling. However, the end compost utilization and quality have been often questioned. This work reports on an integrated pilot scale trial in Al-Sarow Municipality in Jordan. Home compost was produced at the community level, its quality and utilization as a soil amendment to produce food were examined. To evaluate its effectiveness in improving soil productivity, four treatments were evaluated: (1) Control with no fertilizer application (C); (2) Compost at a rate of 20 ton ha−1 (Co); (3) Mineral fertilizers, specifically di-ammonium phosphate and potassium sulfate, at rates of 700 kg and 500 kg ha−1, respectively (F); and (4) Combination of compost and mineral fertilizers (CoF). Sixteen pots, each filled with 4 kg of soil, were planted with maize and irrigated to maintain soil moisture at field capacity throughout the growth period. After harvest, soil and plant samples were analyzed. Applying compost, alone or combined with mineral fertilizers, decreased soil bulk density; increased organic matter content, cation exchange capacity, and nutrient availability, plant growth and nutrient uptake. The CoF treatment demonstrated superior performance, indicating a synergistic interaction that enhanced both plant growth and soil fertility. The combined application of compost and mineral fertilizers is recommended for optimal agricultural productivity and soil sustainability. Implementation of home composting can potentially reduce the climate change impact of Al-Sarow municipality by 14,390 t CO2e/year. Home composting is a valid valorization method to manage kitchen and garden waste while at the same time improving soil fertility and closing the nutrient loop.