Composting is a promising technology for treating organic solid waste. However, greenhouse gases (methane and nitrous oxide) and odor emissions (ammonia, hydrogen sulfide, etc.) during composting are practically unavoidable, leading to severe environmental problems and poor final compost products. The optimization of composting conditions and the application of additives have been considered to mitigate these problems, but a comprehensive analysis of the influence of these methods on gaseous emissions during composting is lacking. Thus, this review summarizes the influence of composting conditions and different additives on gaseous emissions, and the cost of each measure is approximately evaluated. Aerobic conditions can be achieved by appropriate process conditions, so the contents of CH₄ and N₂O can subsequently be effectively reduced. Physical additives are effective regulators to control anaerobic gaseous emissions, having a large specific surface area and great adsorption performance. Chemical additives significantly reduce gaseous emissions, but their side effects on compost application must be eliminated. The auxiliary effect of microbial agents is not absolute, but is closely related to the dosage and environmental conditions of compost. Compound additives can reduce gaseous emissions more efficiently than single additives. However, further study is required to assess the economic viability of additives to promote their large-scale utilization during composting.

Soil salinization and alkalization is a global problem restricting agricultural production. This study compared different fertilizer regimes (addition rate and application depth) on maize growth and soil quality in saline-alkali soil. Cow manure compost was applied with addition rates of 6, 12, 18 and 24 t·ha⁻¹, and application depths of 5 and 20 cm, along with 0.6 t·ha⁻¹ mineral fertilizer, and compared to a control treatment with only mineral fertilizer application. Results indicated that cow manure compost application could promote maize growth and ameliorate soil quality in saline-alkali soil. Increasing cow manure compost addition rate alleviated soil salinity better than alkalinity, while increasing compost application depth could reduce soil alkalinity more effectively than soil salt content. Moreover, increasing cow manure compost addition rate improved soil organic matter and soil nutrient content, thus promoting shoot growth and maize yield. However, increasing cow manure compost application depth could boost root growth, and further absorbed more nutrients to promote maize yield. Cow manure compost application increased maize yield by 6.0% to 28.4% with a maximum yield of 8.14 t·ha⁻¹ in a treatment with compost addition rate of 24 t·ha⁻¹ and application depth of 20 cm. Comprehensive evolution of soil quality, maize growth and maize yield, cow manure compost addition rate of 24 t·ha⁻¹ and application depth of 20 cm along with 0.6 t·ha⁻¹ mineral fertilizer application is suggested for use in saline-alkali soil.