Soil enricher is a term used to describe materials that are added to soil to improve its fertility and structure. Mulch, MANURE, PEAT, and HUMUS are all common soil enrichers. Mulch is a layer of organic material such as wood chips or straw that is spread over the surface of the soil to help retain moisture and reduce weeds. MANURE is a combination of animal waste and bedding material that is used to add nutrients to the soil. PEAT is a type of soil made up of partially decomposed plant material that is used to improve soil structure and increase water retention. HUMUS is a dark, organic material that is formed when plant and animal matter decompose and is used to improve soil fertility.