Water is critical to the survival of all living organisms and that includes all the plants in your garden. Some gardeners and farmers live in regions where rainfall is plentiful during the growing season but if you live in an arid region like I do summer precipitation is almost non-existent and irrigation is essential. Even if you live where adequate precipitation to maintain a crop does usually occur, it may not always come during critical stages of plant growth that can affect quality and yield. Convenient access to a reliable source of water can be a factor in locating your garden. Also what type of irrigation system you choose can impact the layout of the garden.
There have been many developments in irrigation technology since Kain wrote his book “Five Acres and Independence”. He also farmed in a region where irrigation and water conservation were not as critical to farm productivity and sustainability. However, as noted in my first paragraph, even in regions of adequate precipitation you can end up with water stressed plants if the distribution of that moisture doesn’t come at the right time.
The new technologies include drip irrigation, timers, and rain sensors. These technologies can be expensive and depending on your particular situation they may be unnecessary. Some of these technologies only work with particular irrigation systems so it is best to assess what system will work in your situation. For example timers and rain sensors are useless if you have a flood or furrow irrigation system.
Flood and furrow systems require you to personally monitor the field both between and during irrigations. To use these systems you will need to develop a good sense of what adequate soil moisture looks and feels like. Also you must know the critical stages of plant development where water stress could negatively impact yield and quality of your crop.
Timers and rain sensors work better with drip or sprinkler irrigation systems. These systems also tend to be better at conserving water with drip being far superior to sprinkler at water conservation.
Which irrigation system you choose will depend on your source of water and financial resources. Flood and furrow irrigation require gravity to work so your source of water must either be pumped up to the highest point in your garden or field or your source of water must be higher so it can flow to the lower portions of the field. The field or garden must be leveled with a slight slope to allow water to flow from a high point in the field to a lower point. How much slope is required to get uniform irrigation throughout your field or garden will depend on the texture of the soil. Clay soils require less slope than sandy soils to achieve good coverage.
Drip and sprinkler irrigation aren’t as sensitive to field level but do require the ability to pump water into the system whether it is from a well or from a surface body of water. One complication of many agricultural regions of the arid Western United States is they are serviced by irrigation districts that are designed to deliver water to furrow and flood irrigation systems. In order to use drip or sprinkler irrigation, you may need to construct some sort of holding pond or tank for water delivery. From this water holding structure you can pump water into a sprinkler or drip irrigation system.
Flood and furrow irrigation requires the farmer to make the decision as to timing of irrigation and be present while it is occurring. Sprinkler and drip irrigation systems, if hooked up to timers and rain sensors can be allowed to run without the farmer or gardener present during irrigation. However, both drip and sprinkler systems need to be periodically checked for plugged up nozzles and emitters to insure they delivering water.
To help make a decision on which irrigation system will work best for you, talk with other farmers and gardeners in the area you want to garden or farm. Also talk to local Extension agents. Then assess what you can afford and what your source of water will be.