Projects & How To

There are many projects for the urban farmer. One area where an urban farmer has a lot of flexibility is in their irrigation systems. This lets the urban farmer tailor the irrigation requirements to what they are growing and can also save water. Saving water is vital and if the urban farmer is on a river, they might be able to trade the water to another farmer for money.

The best system for an urban farmer is drip irrigation.

Drip Irrigation

This is a way to irrigate by letting the water slowly fall onto the roots of the plants. It can either be dripped onto the soil or directly under the soil on the root zone. The system involves a network of pipes, valves and emitters. This irrigation system uses smaller pipes than many other irrigation systems.

Drip irrigation has been used for thousands of years. It began in earnest in 1860 in Germany when experimenters built a drainage and irrigation system. In the 1920s, perforated pipes were developed for drip irrigation. You can read a detailed history here: http://www.gardenguides.com/79735-history-drip-irrigation.html

Another technology in drip irrigation is micro spray heads that spray water on the area instead of the typically dripping emitters. These are used on plants with roots that stretch greater distances than typical. The other main technology: subsurface irrigation utilises drip tape buried below the plant roots.

These technologies allow the urban farmer to utilise their water resources in a cost effective and water saving way. This is vital because we live in a world facing water scarcity.

Typical drip irrigation system:

Drip Irrigation

Typical components in a drip irrigation system:

  • Pumps
  • Filters
  • Backflow prevention device
  • Pressure regularo
  • Pipes
  • Valves
  • Pipe connectors
  • Emitters

Systems need filters to prevent clogging in the smaller pipes and at the emitters at the ends. This might not be necessary if your system is running from town water, but it’s still recommended to have filters.

Traditional fertiliser might not work in drip irrigation systems because the time release mechanism in the fertiliser doesn’t work with drip irrigation. So many systems employ a fertigator that mixes fertiliser with the irrigation water and applies it to the plants.

Fertigation systems can yield significant savings in fertiliser use. This is because the fertiliser is applied directly to the plants and there is no need for a time release component to the fertiliser.

Drip irrigation systems reduce evaporation and deep drainage because the water is targeted at the roots. It also lowers the chances of diseases spreading on the farm by minimising contact between the leaves and the roots. Sandy soils benefit from drip irrigation’s ability to slowly release water onto the roots.