Compost to improve sustainable soil cultivation and crop productivity

Agricultural waste is one of the biggest concerns related to agronomy. The most effective approach dealing with agricultural waste is compositing. In particular, composting is a biological process in which organic waste is recycled under aerobic conditions into a value-added product that can be safely utilized for crop cultivation or livestock feed. Many factors such as temperature, pH, moisture, oxygen, particle size, and C/N ratio influence the biodegradation rate of the composting process. Temperature ranging from 45 to 55 °C in thermophilic phase, pH in 5.0–7.0, moisture 50–60%, as well as C/N ratio ranging from 25 to 35% has been indicated as the optimum conditions for composting. However, the formation of humic substances, which are by-products of the composting process, plays an important role in improving the chemical, physical, and biological properties of soil that increases crop productivity. Composting has showed its application in the improvement of crop productivity and acid and sality soil cultivation. Primary microbial communities that play key roles during different phases of the composting process and the formation and importance of humic substances has been highlighted. Factors effect on composting process and potential applying their product on soil cultivation has been reviewed, giving a guideline for composting application in the sustainable growth of global agriculture through recycling.