the impact of farm size on irrigation practices and on-farm irrigation efficiency in the elephant...
Post on 21-Dec-2015
223 views
TRANSCRIPT
The Impact of Farm Size on Irrigation Practices and On-Farm
Irrigation Efficiency in the Elephant Butte Irrigation District
Rhonda Skaggs&
Zohrab SamaniNew Mexico State University
Structure of U.S. Agriculture
• Majority of production on few farms
• Off-farm work
• Retirement or residential/lifestyle farms– 54% of all U.S. farms– 7.8% of value of production
• Urban fringe agriculture
• Irrigated river valleys in the West
Irrigation in the West
• 92% of consumptive water use
• Increased competition for water supplies– Municipal– Industrial– Environmental
• Increased irrigation efficiency?– Technologies or techniques
Elephant Butte Irrigation District
• Irrigated farms increased 70%, 1974-1997• Growth in small farms, urban fringe• Dualistic structure pecan production
• This research…– Relationship between farm size & irrigation
practices, efficiency– Potential responses to incentives & water
marketing– Data for 340 pecan orchards
Pecan Farm Size Distribution (2001)
220
67
24 218
0
50
100
150
200
250
2--5 5--10 10--20 20--50 >50Acres
No
. o
f F
arm
s
2001 Pecan Ac-ft vs Acreage
0
1
2
3
4
5
6
7
8
9
10
0 10 20 30 40 50 60 70 80 90 100Farm Size (Ac)
Ac-
ft
2001 Pecan Hrs/Ac/Irrigation vs. Farm Size
0
2
4
6
8
10
0 10 20 30 40 50 60 70 80 90 100
Acres
Hr/
Ac/
Irri
gat
ion
Pecan Average Hrs/Ac/Irrigation (2001)
1.57
0.97
0.76
0.47
0.30
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2--5 5--10 10--20 20--50 >50
Acreage (ac)
Hr/
Ac/
Irri
gatio
n
Irrigation Duration…
• Hours / acre / irrigation• Indicator of irrigation efficiency
– Deep percolation losses
• Long durations due to– Highly permeable soils– Low discharge at farm turnout (infrastructure)– Surface roughness, unleveled fields
• Guideline = 0.5 hrs/ac/irrigation
Field Verification• Low flows• Small on-farm turnouts• Long fields, rough surfaces• Inadequate infrastructure• Easements, access, common property
• Irrigation≈ Recreation≈ Tradition≈ Lifestyle≈ Meditation
Findings…
• Overdelivery to small farms
• Underdelivery to large farms
• Delivery losses or on-farm application?
• Small orchard nut production– 161 lbs / acre-foot
• Large orchard nut production– 300 lbs / acre-foot
Next step…
• Not feasible to survey producers• More field measurements & “conversations” with
water users
• Programming models for different farms– “They don’t want to spend any money.”– “I’m retired, what else have I got to do?”– “I like to listen to the water.”
• Objective functions?
EBID Distribution of Crops