Mole Channel

A hollow horizontal drainage channel produced by the action of a mole plough.

  Mole Drainage

A method of drainage which can be used on heavy clay soils with greater than 35% clay and less than 30% sand content. It is a primary drainage system in which the created drainage channels run into a permanent drainage trench, which is typically located at the edge of a field. The trench will typically have a pipe installed to help transport the drainage water away to an outfall.

  Mor

A type of humus, which is created under acidic conditions, with low microbiological soil activity. The breakdown of this type of humus is relatively slow, with the organic horizon of the soil profile typically having distinct layers of Litter (at the surface), Fermentation, and Humus.

  Motty

A ball of clay moulded and compressed to approximately 25mm in diameter, which is formed from a clay loam. It is dried, shrinks to about 20mm in diameter, and then broken to measure its binding strength in kilograms. More formally it is called the Adams and Stewart Soil Binding (ASSB) test after its inventors. A good binding strength for a cricket loam will typically be from 55kg for good club pitches and better; whilst for tennis courts this will be greater than 35kg.

  Mull

A type of humus which is present in many soil types which are biologically active, with the soil pH being around neutral, and especially under grassland conditions. The O horizon is primarily a Litter layer, with organic material being well mixed into the mineral soil A horizon.

  Natural Drainage

The natural removal of water from a surface without the use of an installed drainage system or specially constructed pitch profile. A slope on a surface will allow water to drain naturally in the direction of the slope, whilst a soil with good soil structure or an open texture will also provide for good natural drainage.

  Neutral Soil

A soil that has a pH value of 7.0.

  Nutrient Loss from a Soil

There are three main ways in which nutrients might be lost from a soil: 1. Through mower clippings or from scarification / verticutting arisings. 2. Leaching of nutrients from a soil profile, especially from a very sandy soil. 3. Where some nutrients are lock-up though soil pH, or where some nutrients, where present in excessive quantities, create an imbalance in the soil and reduce the availability of other nutrients. These situations can be classed as a temporary loss as changing soil pH or correcting imbalances can make other nutrients more available.

  O Horizon

A soil profile layer, often at the surface, which is dominated by organic matter. The organic layer might be of uniform consistency, especially where the pH is around 7.0 and this is termed mull, whilst in contrast in very acidic soils there could be up to three distinct organic layers, a surface litter layer, then fermentation layer and then a lower humus layer, primarily due to the relatively slow breakdown of organic matter in these soil conditions. This is called mor and might be similar to some thatch layers on very acidic golf fairways. Organic horizons that exhibit intermediate stages

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  Open Ditch Drainage System

A ditch which is not filled in with pipework and gravel but kept open to the elements. This might be considered as an outlet for lateral or main drain pipework, or for mole drains. Other situations might include: • Using on silty or unstable soils, such a Gley soils, where subsurface drainage might be unsuitable; • To remove larger volumes of water than can be achieved with pipework; or • Where resources are very limited and excavating or utilizing and existing ditch is the quickest and cheapest option.