Evaluating Center Pivots in Evaluating Center Pivots in MissouriMissouri
Joe HenggelerJoe Henggeler
University of MissouriUniversity of Missouri
38th ANNUAL MISSOURI IRRIGATION CONFERENCE38th ANNUAL MISSOURI IRRIGATION CONFERENCEWednesday, Feb. 2, 2004Wednesday, Feb. 2, 2004
309 Hearnes Center, Columbia, MO309 Hearnes Center, Columbia, MO
Team Up!Team Up!
Irrigation SchedulingIrrigation Scheduling Proper fertigation (corn)Proper fertigation (corn) Testing center pivotsTesting center pivots
Other Data CollectedOther Data Collected Pivot age / total hours of operationPivot age / total hours of operation Pressure at beginning & endPressure at beginning & end
Other Data Collected, Other Data Collected, cont.cont.
Type of sprinklerType of sprinkler Weather conditions during the testWeather conditions during the test
Irrigation Distribution Uniformity (DU)Irrigation Distribution Uniformity (DU)
0
0.5
1
1.5
2
2.5
0% 25% 50% 75% 100%
% of the field this amount or less
Cat
ch (
inch
es)
Catch
Average catch = 1.1”
Average Low Quarter catch = 0.8”
Irrigation Distribution Uniformity (DU)Irrigation Distribution Uniformity (DU)
0
0.5
1
1.5
2
2.5
0% 25% 50% 75% 100%
% of the field this amount or less
Cat
ch (
inch
es)
Catch
Average catch = 1.1”
Average Low Quarter catch = 0.8”
DU = (0.8 1.1) x 100 = 72%
Evaluating Catch AmountsEvaluating Catch Amounts
0.8 “ 1.2 “ 0.3 “ 1.0 “ 0.7 “
(0.8 + 1.2 + 0.3)“3
= 0.7
10 ft
(0.3 + 1.0 + 0.7)“3
= 0.7
(1.2 + 0.3 + 1.0)“3
= 0.8
DU ValueDU Value RatingRating
> 75%> 75% ExcellentExcellent
65 – 74 %65 – 74 % GoodGood
50 – 64 %50 – 64 % FairFair
< 49 %< 49 % PoorPoor
Straight Straight ValueValue
Averaging Averaging CatchCatch
50 %50 % 67 %67 %
82 %82 % 86 %86 %
30 %30 % 45 %45 %
Average
Maximum
Minimum
The EndThe End
Joe HenggelerJoe HenggelerDelta Center Research CenterDelta Center Research Center
573-379-5431573-379-5431
[email protected]@missouri.edu