Magnesium Ammonium Phosphate (MAP)

An inorganic source of nitrogen and phosphate. A typical fertiliser content is 40% phosphate (22% phosphorus), 10% nitrogen, and 17% magnesium.

  Manganese

A micronutrient, which is represented by the chemical symbol Mn. Manganese is involved with the formation of chlorophyll, the activation (i.e. being a cofactor) of many enzymes, and the process of photosynthesis. A deficiency can result in interveinal chlorosis (but this can also arise from manganese toxicity), possibly with misshapen leaves, reduced root and vegetative growth, and with uptake being significantly reduced in alkaline soils. Manganese toxicity can result in plant death, or by interacting with other nutrients resulting in them to become deficient for healthy growth, including Calcium, Iron and Magnesium.

  Manufactured Fertiliser

Any fertiliser that has been produced by industrial means. Compound and straight fertilisers are typically manufactured fertilisers.

  Manure [2]

An old-fashioned term, especially during the early 1900s, for a fertiliser. A good example is given in MacKenzie, Dr. A. (1920) Golf Architecture: " [they] should be used with a considerable amount of discretion and only in small quantities at a time. ... artificials are of the greatest ... value for golfing turf, ... and should be well diluted with soil or sand, and only used during moist weather. A mixture, consisting of superphosphate of lime, Sulphate of ammonia, and Sulphate of potash, supplies most of the feeding that is necessary for golf".

  Micronutrient

An element which is vital for plant growth in relatively small quantities. There are seven plant micronutrients: Boron, Chlorine, Copper, Iron, Manganese, Molybdenum, Zinc (and Nickel for some crops). Cobalt is often included as a micro-nutrient for legume crops. Another term used for a micronutrient is Minor Nutrient, or Trace Element.

  Mineral Element

See Mineral Nutrient.

  Mineral Fertiliser

Any natural or synthetic fertiliser which supplies nutrients to a plant. Sometimes this is used to refer to nutrients which have arisen from mineral ores and/or synthetic manufactured fertilisers, to the exclusion of those of organic origin.

  Mineral Nitrogen

This refers to two particular forms of nitrogen that are taken up by plants: ammonium (NH4+) and nitrate (NO3-).

  Mineral Nutrient

Any chemical element taken up by a plant, primarily via its roots. This is also called Mineral Element.

  Mineral Nutrition

How plants acquire and utilise nutrients for growth and development.