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• Board Meeting Date: 5/21/2008
• Description: IWMD Section - Presentation of Agricultural Water Conservation Paper
• Board Meetings - Doc Type: Memo

Section 4
Agricultural Conservation Measures
Table 4-2 Growing Season and Consumptive Use for Various Crons_ Holvoke_ CO
Growing Season
(Hol oke, CO) Seasonal
Consumptive Use
Crop (Average Dates) (Days) (incheslseason)
Alfalfa 3/20 -10/10 204 35.2
Sugarbeets 4/25 -10/10 168 29.9
Corn/ rain 515 -10/5 153 25.4
Soybeans 5125 -10/5 133 16.4
Sprin rains 4/1 - 7125 115 15.2
Dry beans 6/1 - 9/5 96 18.7
Agricultural Water Conservation Techniques that Reduce Crop
Consumptive Use and Nonproductive Consumptive Losses
Current water law allows irrigators flexibility in diversions, crop types, irrigation
timing, methods, and application rates. If properly managed, it has been shown that
crop consumptive use or nonproductive consumptive losses may be reduced by the
following practices:
^ Lower water use cropping systems
^ Acreage fallowing
^ Shorter season/cool season crops
^ Limited/ deficit irrigation
^ Remove pivot end guns and reduce acres
^ Ditch piping and lining (reducing evaporation, ET, and deep percolation)
^ Crop residue management and mulching
^ Phreatophyte control
Limited/Def icit Irrigation Concepts
Limited or deficit irrigation reduces consumptive use by not meeting full crop ET f or
some part of the growing season. To implement limited irrigation, a system of
practices is required that may incorporate all or some of the following:
^ Irrigation water application is timed for maximum benefit (minimize stress during
critical growth stages)
^ Crop residue maintained to catch moisture and
reduce evaporation
^ Fields are often split to include lower water use
crops (shorter season, cool season crops)
^ Weed control
^ Stress tolerant crop varieties
^ Reduced input costs
DRAFT 4-3