Jeff McCutcheon*, Extension Agriculture and Natural Resources Agent
Phil Rzewnicki, On-Farm Research Coordinator
Objective: To compare the influences of different phosphorus application methods on corn yields.
Background |
|
| Cooperator:
County: Nearest Town: Major Soil Type: Drainage: Tillage: Previous Crop: Soil Test: |
Keith Dennis
Perry Rushville Centerburg and Luray Improved Minimum Till Corn pH 6.5 P 23 ppm K 114 ppm CEC 9 meq/100 g |
| Hybrid:
Planting Rate: Planting Date: |
Seed Consultants 1134
27,200/acre May 2, 1999 |
A study was designed to compare corn yields under two different phosphorus placement programs. Plots were field length (>750 ft.) and 54 ft. wide, replicated six times and completely randomized. Anhydrous ammonia was used at a rate of 190 lb N/acre on all three treatments. One fertilizer program was the broadcasting of 100 lbs/acre of diammonium phosphate or DAP (18-46-0). The second fertilizer program was the same rate of DAP placed about eight inches in the soil profile when the anhydrous was injected. A third treatment was a half rate of the DAP (50 lbs/acre) placed at about eight inches in the soil profile. All fertilizer applications were made on April 26 or six days before planting.
All plots received a surface tillage pass with an Aerway unit. The shallow tillage probably incorporated the broadcasted fertilizer to a depth of two to three inches. This is the second year for this trial using the same treatment areas as the previous year.
| Average Treatment |
Harvestable
Yield Bu/Ac1 |
Treatment Population |
Cost/Ac.2 | |||
| Broadcast Full Rate | 98.81 | 9,630 | $20.32 | |||
| Full Rate Deep Placement | 93.49 | 11,170 | $23.26 | |||
| Half Rate Deep Placement | 94.99 | 12,430 | $13.89 | |||
| NS3 | NS4 | |||||
| 1 @ 15% moisture.
2 Includes actual fertilizer cost, plus estimated machinery and fuel cost based on łOhio Farm Machinery Economic Cost Estimates for 1999.˛ 3 F<1, CV= 9.94% ; 4 F= 2.62, CV= 18.41% |
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Yields were down due to lack of rain. Rainfall during the growing season was approximately 10 inches below normal. Finding no significant differences between the three treatments was not surprising when considering the soil test values being above the critical level for phosphorus. Past research indicates that if soil test values are above the critical level then specific placement of the fertilizer will have no significant effect on yield. This trial should also be done on a field that has soil test values below the critical level. In that case, past research indicates that fertilizer placement will have a greater effect on yield.
*For additional information, contact:
Ohio State University Extension, Perry County
104 S. Columbus St., P.O. Box 279
Somerset, OH 43783
740-743-1602
mccutcheon.30@osu.edu