Irrigation Efficiency
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Why irrigation efficiency is important:
Demand and rainfall
Providing an adequate amount of water to farm fields is essential for growing high-quality crops. Although we often think of Western Oregon as a rain-abundant region, summers are very dry and can include long periods without rainfall. Many of the crops grown in the Willamette Valley require irrigation throughout the summer.
- Fun fact:
Nearly 80% of water use in Oregon is for agricultural purposes [1].
The challenge:
Water is not a limitless resource.
Our water supply is facing increased pressure from climate change and expanding populations. Surface water sources are reaching their withdrawal limitsAmount of water that is allowed to be taken from ground or surface water sources. and groundwater stores are steadily declining.
Farmers can play a large role in water conservation. Irrigating crops efficiently allows more water to remain in our waterways, providing important habitat for fish and other aquatic species. Managing irrigation with conservation in mind can result in cost savings, reduced labor, and increased resiliency to water limitations.
Strategy & action:
How can you conserve water on your irrigated crops?
Irrigation efficiency practices can help you produce high-quality crops while using less water.
Use a high-efficiency irrigation system
Many irrigation systems distribute much more water across a field than a crop actually needs. This leads to overwatering in some areas and underwatering in others, making it difficult to ensure consistent crop quality. By converting to a precise system that directs water where it’s needed, when it’s needed, you can greatly reduce your water usage while ensuring your crops are getting just what they need.
Drip irrigation systems (sometimes referred to as micro-irrigation) are the most efficient way to water crops. They direct water straight to the root zone of the crops, reducing the amount of water lost to evaporation and runoffThe flow of excess water running over a surface..
High-efficiency systems can save you money by reducing the amount of water used as well as reducing the amount of soil and fertilizer lost to runoff. They also save time by eliminating the need to move more labor-intensive systems, like hand lines.
Learn About Drip Irrigation Systems at OSU
- Fun fact:
Converting to a drip irrigation system can result in a 25% to 35% reduction in water use compared to “big gun” or hand line sprinklers.
Establish an irrigation water management plan
Irrigation is not a one-size-fits-all practice. While many irrigation systems are designed to deliver water on a fixed schedule, that often isn’t what the crop needs. The ideal amount of water applied to a field is dependent on soil conditions, crop needs, and the slope or position of the land.
An irrigation water management plan outlines a schedule of how much water to apply to a field and when to apply it, based on the crop’s needs and the conditions of the field.
An irrigation plan can be determined by:
Soil moistureMonitoring soil moisture content (either by look and feel or by using soil moisture sensors), and
Read USDA's Estimating Soil Moisture by Feel and Appearance
Assessing the water needs of your specific cropsYou can explore the water needs for crops in your area by referring to the Agrimet website or checking with Oregon State University Extension.
If you’re interested in creating an irrigation water management plan, contact our Rural Conservation Program.
Maintain healthy soils
Soil with a high proportion of organic matter has higher water holding capacity, and will keep water in the soil’s root zone longer. Adding organic matter (compost) can increase the amount of water that remains available to the crop. Adding mulch to the surface of the soil can help slow the evaporation of water.
Learn About Healthy Soil
Our Rural Conservation Program can provide recommendations for improving your irrigation systems to reduce water use.
Source:
1. United States Geological Survey. (2009). 2005 Oregon Water Use Compilation Results.
Retrieved from http://or.water.usgs.gov/projs_dir/or007/or007.html