Why is drainage necessary?
Waterlogged soils result in reduced crop yields as air can’t circulate to the plants roots which limits plant respiration. The main objective of any land drainage system is to remove excess water from the soil as quickly as possible, lower the water table, and reduce the period of waterlogging.
Benefits of improved drainage:
- Increased yield due to better uptake of water and nutrients
- An extended growing and grazing season
- Improved stock carrying capacity and utilisation of grazed grass by livestock
- Reduced surface damage by livestock
- Improved accessibility for machinery
- Reduced disease risk to livestock
- Better water infiltration
The first step to improve drainage is to dig a few soil inspection pits in order to determine the cause of the problem. The type of field drainage system needed will depend on the nature of the problem, which could be either a high ground water table, a heavy poor draining clay soil or springs. If drainage is required it is advised that the drain layout of the field be mapped so that they can be maintained in years to come and for farm succession.
A number of drainage techniques have been developed to suit different soil types and conditions. There are two main categories of land drainage:
- Groundwater drainage system
- Shallow drainage system