Ray Massey
University of Missouri Outreach and Extension and Commercial Agriculture Program

This is the 21th year the University of Missouri has collected data from Missouri farmers on irrigation performance. The data presented here are the average values for 21 irrigation systems which responded to our December 1998 survey. Individual farms may report more than 1 system. Irrigation systems located in the bootheel region of southeast Missouri are not included in this report.

The number of surveys returned was down this year from previous years. Many respondents indicated that they did not irrigate this year due to adequate rainfall. Survey respondents included 18 irrigation systems irrigating corn and 14 systems irrigating single-crop soybeans in Missouri in 1998.

Respondents reported that corn yields from land irrigated with an average of 3.0 inches of water exceeded dryland corn yields by 22 bushels. Irrigated single-crop soybean yields exceeded dryland yields by 8 bushels, with 3.3 inches of water being applied.

Seventy-eight percent of the systems were center pivots, 11% were traveling guns and 11% were some other type of system. Pumping power was about evenly split between diesel and electricity with a much smaller percentage using natural gas. One hundred percent of the respondents reported that their irrigation water supply was adequate. 100% of those that used reservoirs reported that their reservoirs were full in June.

Weather and market prices worked together to make irrigation unprofitable in 1998. This year the net return to land and management for corn was very low at $12.74/acre while for single crop soybeans it was low at $62.75/acre. Neither is high enough to give a normal return to land ownership. The income change due to irrigation was negative for both corn and soybeans. The wet conditions of the summer of 1998 caused many to make little use of their irrigation system and, of those that did irrigate, market prices were depressingly low for their production.

1997 Irrigation Survey Crop Details

Single-crop Soybeans
Double-crop Soybeans
Number reporting52397
Average acres irrigated13412170
Irrigated yield/acre (bushels)142.652.936.7
Dryland yield/acre (bushels)97.340.921.0
Increase (bushels/acre)45.312.015.7
Times irrigated4.43.72.5
Total inches applied4.74.03.3

Missouri 1997 Irrigation Survey (excluding Bootheel)

Types of Systems
    Center Pivot78%
    Traveling gun13%
Types of Water Supplies
    Combination, reservoir/stream/well16%
Types of Pumping Power
    Diesel/Electric combination2%
1997 Average Fuel Cost per Acre Inch:
    Diesel (20 systems)$2.37
    Electricity (17 systems)$1.92
    Propane (2 systems)$2.43
    Natural Gas (6 system)$3.89
    Average (44 systems)$2.28
1997 Repair Costs:
    Average per farm (50 farms)$857.94
    Average per acre$7.15
Water Supply Adequate?97% yes
Reservoir full in June?96% yes
20 Year Survey Corn Yields, average:
    Irrigated142.0 bushels/acre
1997 Average Corn Planting Rate:
    Irrigated27373 stalks/acre
    Dryland23541 stalks/acre
20 Year Survey Soybean Yields, average:
    Irrigated45.8 bushels/acre