Skip to main content
Calcimator

Water Use Efficiency Calculator

Calculate crop water use efficiency, irrigation WUE, water productivity, and economic returns from irrigation vs. dryland farming.

Inputs

%

Results

Crop WUE (bu/in ET)

8.33

Irrigation WUE (bu/in irrigation)

8.57

Water productivity ($/in)$50.00
Yield gain from irrigation (bu/acre)120
Marginal revenue ($/acre)$660.00
Irrigation cost ($/acre)$84.00
Net return from irrigation ($/acre)$576.00
Irrigation ROI ($/$ spent)7.86
Supply/demand ratio (%)87.5
Total field net return ($)$57,600.00
WUE rating (1=Excellent, 4=Poor)2
Dry-matter yield (bu/acre)169
Transpiration (in)19.2%
Total Revenue$110,000.00
Total Irrigation Cost$8,400.00
How to Use This Calculator
  1. Enter Irrigated yield (bu/acre), Dryland yield (bu/acre), and Seasonal crop ET (in).
  2. Set Irrigation applied (in), Effective rainfall (in), and Crop price ($/bu).
  3. Adjust Irrigation cost ($/acre-in), Field size (acres) as needed.
  4. Review Crop WUE (bu/in ET) and Irrigation WUE (bu/in irrigation).
  5. Use Water productivity ($/in) ($) and Yield gain from irrigation (bu/acre) to inform your decision.

How the result changes with Seasonal crop ET (in)

Seasonal crop ET (in)Crop WUE (bu/in ET)Irrigation WUE (bu/in irrigation)
6.928.998.57
229.098.57
395.138.57
543.78.57

What each input means

Irrigated yield (bu/acre)
Actual crop yield under irrigation.
Dryland yield (bu/acre)
Expected yield without irrigation (rain-fed only).
Seasonal crop ET (in)
Total season evapotranspiration.
Irrigation applied (in)
Total irrigation water applied during the season.
Effective rainfall (in)
Rainfall that contributed to crop water use (not runoff or deep percolation).
Crop price ($/bu)
Expected market price per bushel.
Irrigation cost ($/acre-in)
Total cost per acre-inch of irrigation (pumping + labor + maintenance).
Field size (acres)
Total irrigated field area.
Grain moisture (%)
Harvest moisture content for dry-matter WUE calculation.

What each result means

Crop WUE (bu/in ET)
Bushels produced per inch of crop evapotranspiration.
Irrigation WUE (bu/in irrigation)
Additional bushels produced per inch of irrigation applied.
Water productivity ($/in)
Revenue generated per inch of total water consumed.
Yield gain from irrigation (bu/acre)
Additional yield compared to dryland.
Marginal revenue ($/acre)
Additional revenue from irrigation vs. dryland.
Irrigation cost ($/acre)
Total irrigation cost per acre.
Net return from irrigation ($/acre)
Profit from irrigating vs. dryland per acre.
Irrigation ROI ($/$ spent)
Revenue per dollar spent on irrigation.
Supply/demand ratio (%)
Irrigation applied as % of net irrigation need.
Total field net return ($)
Net return from irrigation for the entire field.
WUE rating (1=Excellent, 4=Poor)
1=Excellent (>9), 2=Good (7-9), 3=Fair (5-7), 4=Poor (<5).
Dry-matter yield (bu/acre)
Yield adjusted to dry-matter basis.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Irrigated yield (bu/acre) = 200, Dryland yield (bu/acre) = 80, Seasonal crop ET (in) = 24, Irrigation applied (in) = 14 = 9 input(s) provided
  2. Calculate Crop WUE
    8.33 = 8.33
  3. Calculate Irrigation WUE
    8.57 = 8.57
  4. Calculate Water productivity
    50 = $50
  5. Calculate Yield gain from irrigation
    Yield gain from irrigation = cropYieldBuPerAcre - drylandYieldBuPerAcre
    120 = 120

Related Calculators

The questions that sit next to this one — chosen by subject, including calculators filed under a different category.

Precision Irrigation

Irrigation Return on Investment Calculator

Evaluate irrigation system ROI with NPV, IRR, payback period, and benefit-cost ratio from yield improvement, water savings, and energy savings.

Precision Irrigation

Irrigation Energy Cost Calculator

Calculate pumping energy cost from Total Dynamic Head, flow rate, pump and motor efficiency, and electricity or diesel prices.

Precision Irrigation

Salinity Management Calculator

Calculate leaching requirement from irrigation water EC and crop salt tolerance using FAO guidelines, plus SAR and salinity hazard assessment.

Green Building

Water Efficiency Calculator

Calculate indoor water use savings from efficient fixtures compared to EPA baseline for LEED WEc2 credit analysis.

More in Agriculture & Farming.