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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #321815

Research Project: Integrated Water and Nutrient Management Systems for Sustainable and High-Quality Production of Temperate Fruit and Nursery Crops

Location: Horticultural Crops Research Unit

Title: Irrigation scheduling: When, where, and how much?

Author
item Bryla, David

Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/2/2015
Publication Date: 4/1/2015
Citation: Bryla, D.R. 2015. Irrigation scheduling: When, where, and how much? Proceedings from OSU Blueberry School; 2015 March 16-17; Corvallis, OR. p. 63-68.

Interpretive Summary:

Technical Abstract: Irrigation scheduling, a key element of proper water management, is the accurate forecasting of water application (amount and timing) for optimal crop production (yield and fruit quality). The goal is to apply the correct amount of water at the right time to minimize irrigation costs and maximize crop production and economic return. Many techniques and technologies can forecast the date and amount of irrigation water to apply. The appropriate technique or technology is a function of the irrigation water supply, technical abilities of the irrigator, irrigation system, crop value, crop response to irrigation, cost of implementing technology, and personal preference. This paper illustrates the use of weather-based approach for accurately estimating daily water requirements of blueberry. It is important to understand that a crop’s irrigation requirements differ considerably from its actual water requirements. Crop water requirements indicate the total amount of water directly used by a crop but do not account for any extra water needed to compensate for non-beneficial water use or loss, e.g., run-off, deep percolation, evaporation, wind drift, ground cover, weeds, etc. Additionally, irrigation systems do not apply water with 100% uniformity. For accurate irrigation scheduling, these losses must be evaluated for each system. The most common systems used to irrigate blueberries are sprinklers and drip. The timing or frequency of water applications will depend on soil texture (e.g., sand versus clay), the irrigation system used (e.g., drip versus sprinkler), the rate at which the plant is using water, and the overall development of the plant’s root system. Blueberry is a shallow-rooted plant compared to many perennial fruit crops. The roots of highbush blueberry are usually located in the top 18 inches of soil and are often most concentrated near the soil surface. Consequently, when water demands are high, blueberry plants quickly deplete the water from their root zone and require frequent applications of water in order to avoid water stress (drought).