Evaluating Center Pivots in Missouri Joe Henggeler University of Missouri University of Missouri 38th ANNUAL MISSOURI IRRIGATION CONFERENCE Wednesday, Feb. 2, Hearnes Center, Columbia, MO

Team Up! Irrigation Scheduling Irrigation Scheduling Proper fertigation (corn) Proper fertigation (corn) Testing center pivots Testing center pivots

Conducting a Test

Other Data Collected Pivot age / total hours of operation Pivot age / total hours of operation Pressure at beginning & end Pressure at beginning & end

Other Data Collected, cont. Type of sprinkler Type of sprinkler Weather conditions during the test Weather conditions during the test

Distribution Uniformity Average catch of Low Quarter Average catch DU = x 100

Irrigation Distribution Uniformity (DU) Average catch = 1.1” Average Low Quarter catch = 0.8”

Irrigation Distribution Uniformity (DU) Average catch = 1.1” Average Low Quarter catch = 0.8” DU = (0.8  1.1) x 100 = 72%

Evaluating Catch Amounts 10 ft

Evaluating Catch Amounts 0.8 “ 1.2 “ 0.3 “1.0 “0.7 “ 10 ft

Evaluating Catch Amounts 0.8 “ 1.2 “ 0.3 “1.0 “0.7 “ ( )“ 3 = ft ( )“ 3 = 0.7 ( )“ 3 = 0.8

Lots of data !

Problems with Systems

DU Value Rating > 75% Excellent 65 – 74 % Good 50 – 64 % Fair < 49 % Poor

Results

Results, cont.

Straight Value Averaging Catch 50 % 67 % 82 % 86 % 30 % 45 % Average Maximum Minimum

Locations of Pivots Tested 2004 Tested 2003 Tested < 2003

The End Joe Henggeler Delta Center Research Center