Land application refers to the practice of applying organic waste materials, such as manure, biosolids, or compost, to agricultural land as a method of recycling nutrients and improving soil quality. This practice helps to replenish soil fertility, enhance crop productivity, and reduce the need for chemical fertilizers. Land application research typically focuses on optimizing the application rates and timing of organic waste materials, assessing their impacts on soil health and crop yield, evaluating potential environmental risks such as nutrient runoff or leaching, and exploring the potential for greenhouse gas emissions. Overall, land application research plays a crucial role in sustainable agriculture by promoting the efficient use of organic waste materials while minimizing environmental impacts.