Drainage is an important issue because most plants cannot survive waterlogging for more than a short time. Most plants need at least 10% to 15% of the soil pore to be filled with air to survive. Soil becomes waterlogged when its pores fill with water. Once the soil is saturated, root growth in most plants can occur only on the surface. When there is more water than the soil pores can hold, the water will collect on the soil surface and drain by gravity to the lowest point.
Surface drainage is the removal of water that collects on the land surface. Many fields have low spots or depressions where water ponds. Surface drainage techniques such as land leveling, construction of ditches or waterways can allow the water to leave the field rather than causing prolonged wet areas.
Subsurface drainage removes excess water from the soil profile and reduces the watertable below theroot zone. Subsurface drainage is used where surface drainage is not effective. With subsurface drainage, slotted polydrain is installed below the surface, covered with gravel to prevent soil particles from being carried into the drain and to improve the flow of the water.
TG Drains installs subsurface drainage using a laser controlled, purpose built, drainage machine. Both machines are imported from the UK. The 26/15 can cut a trench up to 3.0 metres deep and the 20/15 can cut a trench up to 2.2 metres deep. The digging chain of the machine cuts a trench on the design grade and the drainage pipe is laid with a backfill of gravel in one single operation.
A tractor hauling a gravel trailer with a conveyor belt drives along side the drainage machine to deliver a continuous flow of clean, fine gravel into the machine's hopper. This avoids slumping of the trench walls and prevents excavated material falling on the pipe and possibly blocking the drainage slots. The elevation of the gravel hopper at the back of the drainage machine can be altered hydraulically, allowing the thickness of the permeable backfill to be varied according to the soil type.
After the drains are installed, TG Drains can backfill the trenches with their custom built, V-shaped bade, which fits in the 4 in 1 bucket of the backhoe.
To ascertain the optimum position of the drains we can take our own levels or if a large part of the farm is involved, or a drainage plan is to be put in over a number of years, we use farmmaps created by Farmworks.
All installed drains are GPS mapped for future reference.
Copyright © TG Drains 2020- All Rights Reserved.