Economic and Ecological Impacts of Agricultural Waste Recycling in Integrated Plant Protection Systems
Agricultural waste recycling offers a circular approach to reducing residue burdens while supporting soil management, crop protection, and resource recovery. This review evaluates the ecological and economic impacts of incorporating compost, digestate, biochar, and related products into integrated plant protection systems. A structured narrative review of peer-reviewed literature published between 2003 and 2026 was conducted, covering disease suppression, nutrient cycling, crop productivity, greenhouse-gas emissions, life-cycle performance, and economic viability. The evidence indicates that compost provides the strongest support for suppressing soil-borne diseases through microbial competition, antibiosis, and modification of the soil environment, whereas biochar can enhance nutrient retention, regulate rhizosphere microbial communities, and induce plant resistance, although its effectiveness depends on feedstock, production conditions, and application practices. Digestate contributes primarily through nutrient recovery and renewable-energy production, with limited evidence of direct pest or disease suppression. Economic benefits include reduced fertilizer and pesticide inputs, avoided waste-disposal costs, renewable-energy generation, improved crop productivity, and potential carbon value, although these gains may be offset by processing costs, transportation, emissions, nutrient losses, and inconsistent field performance. Thus, recycled agricultural products should be regarded as complementary, context-dependent components of integrated plant protection, supported by standardized product characterization, long-term field validation, and integrated ecological and economic assessment.