Jack Myrick Technical Coordinator

Irrigation Efficiencies Grants Program

509.301.2498jmyrick@scc.wa.gov

Limited IrrigationLimited Irrigation

As a result irrigation management for marginal and limited water supply is morecritical than ever before.

•MARGINAL water supply with proper management and efficiencies where stillable to meet the crop evapotranspiration.

•LIMITED when water supplies are restricted so that full evapotranspiration demands can not be met.

Irrigation 101Irrigation 101The On-Farm Water BudgetThe On-Farm Water Budget

• ETET• RainfallRainfall• IrrigationIrrigation• Soil “Reservoir”Soil “Reservoir”• Irrigation EfficiencyIrrigation Efficiency

– Canopy LossCanopy Loss– Spray Evaporative LossSpray Evaporative Loss– Wind DriftWind Drift– Deep PercolationDeep Percolation– RunoffRunoff– LeaksLeaks– Non-Uniform ApplicationNon-Uniform Application

Supply and DemandSupply and Demand

What’s so tough about irrigation?What’s so tough about irrigation?

How much water do I need?How much water do I need?

How often do I water?How often do I water?

How long should I water?How long should I water?

What type of soils do I have?What type of soils do I have?

Is my water applied uniformly?Is my water applied uniformly?

KNOW THE CAPABILITY OF THE IRRIGATION SYSTEM

•Application rate / inches per hour or inches per day•Uniformity•Efficiency•How often

FIX THE LEAKSFIX THE UNIFORMITY

KNOW THE SOIL(s)

•Moisture holding capacity•Intake rate•Depth

KNOW THE CROPS•Irrigation requirement•Effective root zone•MAD•Critical growth periods

LIMITED IRRIGATION PRACTICES

•Reduce irrigation during non critical growth stages•IWM know ET & soil moisture•Residue management•Tillage•Manage soil water depletion•Crop rotation