Good drainage is of vital importance in the production of both cereals and root crops, as it maximises yield and allows more flexibility in timeliness, as the soil will dry out quicker allowing early entry for field operations.
Good drainage will also assist with maintenance of a good soil structure and help subsequent crops to become established.
Land drainage design tends to fall into three categories with soil type, terrain and land use determining the final design.
- Peat and fen soils require a high level of drainage because of the intensity of cropping; and with the shrinkage of the peat over the years, the clay subsoil is getting closer to the surface. Drain spacing varies from 10 to 40 metres apart with 20 being the norm. Stone backfill to the clay horizon and single outfalls are recommended.
- Clay soils represent the other soil type where the majority of land drainage is carried out, with the quality of the clay subsoil and fall on the land determining the drainage design. Drain spacing will vary between 20 and 100 metres, with the 100 metres spacing being reserved for the very best clay fields with a good even slope for the moles. In these soils regular mole draining plays a major part in field drainage.
- The third type of soils are those which have very little or no clay content within drain depth, but still have a need for land drainage. Soils that have a deep layer of clay holding up the filtration of water also fall into this category. These soils have traditionally been drained at 14 metres apart and no stone backfill, although drainage at 20 metres apart and a stone covering is an alternative.
Agricultural drainage makes up a large part of our business with Miles Drainage offering a quality GPS based design, installation and maintenance service for all types of farmland throughout the East Anglia and beyond, as well as the installation of water supplies and irrigation mains.
The full article can be found in Septembers issue of Farmers Guide 2017