What is variable rate irrigation?
Variable rate irrigation or VRI is “the ability to spatially vary water application depths across a field to address specific soil, crop, and/or other conditions” (Evans and others, 2013).
How does variable rate irrigation work?
VRI technology works by applying water at a variable rate along the center pivot rather than one uniform rate along the entire length of the system. VRI uses Global Positioning System (GPS) and Geographic Information System (GIS) technology to prescribe a specific amount of water for certain areas of the field.
What are some problems with irrigation?
Adverse impacts
- Reduced river flow.
- Increased groundwater recharge, waterlogging, soil salinity.
- Reduced downstream river water quality.
- Affected downstream water users.
- Lost land use opportunities.
- Groundwater mining with wells, land subsidence.
- Case studies.
- Reduced downstream drainage and groundwater quality.
What are the problems of irrigation in agriculture?
Evaluations document a wide range of problems, including: cost and time overruns; poor management; the non-realization of full, planned benefits; adverse environmental and health impacts; and the exacerbation of inequities in the existing social and economic distribution of assets among farmers.55 Box 18 summarizes the …
What are two problems that can result from irrigation?
There are many positive impacts of irrigation on the environment. Among the negative impacts which appear in the mentioned spheres prevalent impacts is the danger of waterlogging and salinization of soils and waters, rise in groundwater table, spread of water born diseases, pollution of waters and many others.
What are the positive and negative effects of irrigation?
The effects may be water mining, land/soil subsidence, and, along the coast, saltwater intrusion. Irrigation projects can have large benefits, but the negative side effects are often overlooked. The lower the irrigation efficiency, the higher are the losses.
What are the two main problems of irrigation?
Problems and issues of irrigation system in Pakistan
- Improvement and up gradation.
- Salinity and water logging issues.
- Irrigation system turning during rainy weather.
- water pressure issues.
- over watering and under watering.
- water runoff and polling.
- Over exploitation of fresh ground water.
- Insufficient cost recovery.
What is potential drawback to increased irrigation?
Irrigation has a downside: The biggest problem resulting from excessive irrigation in agriculture is that it has contributed to depletion of groundwater and surface water supplies in many areas of the world.
What type of irrigation is most efficient?
Drip irrigation
Drip irrigation is the most water-efficient way to irrigate many different plantings. It is an ideal way to water in clay soils because the water is applied slowly, allowing the soil to absorb the water and avoid runoff.
How does variable rate irrigation improve food production?
With an increasing demand for food production, variable rate irrigation (VRI) is a technology that may improve irrigation water productivity (yield produced per unit of water diverted for irrigation).
Which is the best irrigation system with VRI?
Valley Irrigation, for example, offers three primary ways growers can incorporate VRI into their pivot irrigation system for best results. The first and most basic level of VRI is adjusting application speed.
How are sprinklers spaced in a valley irrigation system?
Valley irrigation offers a system, the Trimble Irrigate-IQ, that allows this level of precision application. While spacing varies from pivot to pivot, generally, sprinklers are spaced around eight-feet apart. Just as the name implies, the system allows control over each individual sprinkler, providing application accuracy within feet.
How is VRI based on soil water sensors?
VRI based on soil water sensors reduced irrigation by 0.5 inch for soybeans and by 0.1 inch for corn ( Barker et al., 2018b ). Ongoing research is utilizing imagery from unmanned aircraft and is continuing to develop SETMI as a decision support tool for VRI management.