What type of fertilizer do manure and sewer sludge represent?

Manure and sewer sludge are considered organic fertilizers because they are derived from natural biological processes involving the decomposition of organic matter. Organic fertilizers, like manure and sewage, provide essential nutrients to plants in a form that is often more beneficial than synthetic alternatives. They not only supply nutrients such as nitrogen, phosphorus, and potassium but also add organic matter to the soil, which improves soil structure, enhances moisture retention, and promotes microbial activity beneficial for plant health.

In the context of fertilization, using organic materials can lead to long-term benefits for soil fertility and overall ecosystem health. These materials are typically less concentrated than synthetic fertilizers, which is why their application usually requires larger volumes to achieve the desired nutrient levels in plants. However, the sustained release of nutrients from organic fertilizers means they can improve the soil over time, contributing to a more balanced and sustainable agricultural practice.