MANUR - Feces, urine, other excrement, and bedding produced by livestock that has not been composted.
METHANE (CH4) - The principal component of natural gas that is associated with all hydrocarbon fuels. It is an important greenhouse gas with a global warming potential approximately 21 times higher than carbon dioxide (on a 100-year time frame). Methane emissions are generated by the decomposition or conversion of carbon compounds in the absence of oxygen (i.e., anaerobic conditions), such as in landfills, peat bogs, the intestines (especially of ruminants), or in an anaerobic lagoon or digester.
MINERLIZATION: The process by which plant nutrients in soil organic matter are released by microbial action into soluble or available forms, which plants can absorb. Nitrogen mineralization is ammonification. For example, organic forms of nitrogen are converted to nitrate.
MINIMUM TILL (REDUCED TILL) - Tillage system that does not involve soil inversion and maintains a high level of surface residue.
MOLDBOARD PLOW - Traditional primary tillage tool consisting of the following key ground engaging parts: the plow share (slices the soil horizontally), the moldboard (lifts and rolls the soil, bringing about inversion), the landside (transfers the sideways thrust), and the coulter (slices the soil vertically). The coulter is essential if plowing sod or soil with significant residues. The moldboard plow is often the best tool for breaking sod.
MONOCULTURE - A field with a single crop in it, or pertaining to such a field.
MULCH - Any non-synthetic material, such as wood chips, leaves, or straw, or any synthetic material included on the National List for such use, such as newspaper or plastic that serves to suppress weed growth, moderate soil temperature, or conserve soil moisture.
MULCH TILL - Full-width tillage involving one or more tillage trips that disturbs all of the soil surface, and is done prior to and/or during planting, but leaves residues concentrated at the soil surface. Tillage tools such as chisels, field cultivators, disks, sweeps, or blades are used. Weed control is accomplished with crop protection products and/or cultivation.