Difference between revisions of "Irrigation"
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When it comes to irrigation water, efficiency is often thought of as minimizing use of water at all costs. However, in a regenerative agriculture system, the [[definition of efficiency]] must be more [[holistically]] derived. Efficiency in using every available drop of water to grow crops regardless of the cost in energy, capital and labor can be a destructive and non-regenerative task which can ultimately result in destruction of eco-systems (by diversion of rivers or springs or lowering a [[water table]] by pumping for example), pollution and a waste of energy. | When it comes to irrigation water, efficiency is often thought of as minimizing use of water at all costs. However, in a regenerative agriculture system, the [[definition of efficiency]] must be more [[holistically]] derived. Efficiency in using every available drop of water to grow crops regardless of the cost in energy, capital and labor can be a destructive and non-regenerative task which can ultimately result in destruction of eco-systems (by diversion of rivers or springs or lowering a [[water table]] by pumping for example), pollution and a waste of energy. | ||
Revision as of 10:43, 7 February 2015
Contents
Comparing irrigation types
Capital cost, water and land scarcity, land tenure, water right security, investment and labor availability. See alsoDefining efficiency in water usage
Surface Irrigation
Also called "flood Irrigation" using pipe systems, ditch systems or vinyl pipe
Furrow irrigation
Paddy irrigation
Sprinkler irrigation
Installed sprinkler systems
Surface hose systems
hand line systems
wheel line systems
Center pivot systems
Drip Irrigitation
t-tape
subsurface drip
Defining efficiency in water usage
When it comes to irrigation water, efficiency is often thought of as minimizing use of water at all costs. However, in a regenerative agriculture system, the definition of efficiency must be more holistically derived. Efficiency in using every available drop of water to grow crops regardless of the cost in energy, capital and labor can be a destructive and non-regenerative task which can ultimately result in destruction of eco-systems (by diversion of rivers or springs or lowering a water table by pumping for example), pollution and a waste of energy.
To define efficiency we must begin with an understanding of a system's limitations. It's often useful to do an audit, or calculation of the final cost/benefit ratio of an agricultural system in terms of the energy, labor, water and capital (in both materials and financial resources) required and the value of the crop produced in both economic and nutritional terms.
Drip irrigation systems are frequently spoken of as "highly efficient" because of the low throughput of water required to raise a crop. But they can be characterized as highly inefficient in terms of materials (lots of plastic pipe and fittings are needed and the need to be frequently replaced), energy (pumps must push the water through filers and networks of pipe with high friction losses) and labor (installation and maintenance labor as well as additional labor for hand weeding where mechanical weeding would interfere with pipes.
Where labor AND capital are plentiful but water is scarce and there is a great demand for fresh vegetables, places like Israel/Palestine or Arizona for example, it may be worth considering drip irrigation. However even in these situations, energy and materials usage as well as impact to the local ecosystem and financial cost of a proposed agricultural system might mean that it would actually be better to transport vegetables from a region with a lower impact to raising vegetables, or indicate that the local diet and population base is not sustainable in that environment. A holistic cost/benefit analysis of using systems like drip irrigation may produce surprising results to people who assume that those systems are the "most efficient"
