Research on Composting of Garden Waste and Its Application in Cultivation Substrates

To achieve the resource utilization of garden waste, in this study, we used garden waste as the main raw material and conducted static composting with high-temperature aerobic treatment and forced ventilation by adding appropriate external additives. Our results showed that during the composting process, the pH was weakly alkaline, and the electrical conductivity was between 1.42 and 1.50 mS/cm. The E4/E6 (an important indicator of the quality or degree of condensation and aromatization of humic acid) gradually decreased, and nitrogen, phosphorus, and potassium contents increased. The germination index gradually rose and ultimately exceeded 80%. Treatment (T2) with a final C/N ratio of 25:1 and the addition of 0.3% bacterial agent resulted in the highest nutrient content and the best degree of compost maturity. All indicators met the requirements of the Chinese “Technical Requirements for Urban Landscape Waste Resource Recycling and Deep Processing (GB/T 40199-2021)”. When using a composite substrate of garden waste and other horticultural substrates for planting, a membership function was executed for comprehensive evaluation. The V (T2):V (peat):V (vermiculite):V (vermiculite) = 135:135:30:00 substrate treatment resulted in optimal lettuce growth and quality. In summary, combining the compost products of garden waste with traditional cultivation substrates at a specific ratio shows favorable applicative prospects.