Greg La Barge, Extension Agent, Agriculture and Natural Resources
Objective
To determine the effects of foliar fertilizer sources, application frequency, and rates on soybean yield.
Background
| Cooperator: | Nate Andre | Fertilizer Rate: | See Treatments |
| County: | Fulton | Hybrid/variety: | Garst 295 |
| Soil Type: | Mermill loam | Planting Date: | April 25, 2000 |
| Tillage: | No-till | Seeding Rate: | 200,000 seeds/A |
| Previous Crop: | Corn | Harvest Pop: | 180,000 plants/A |
| Soil Test: | pH=7.1, P= 33 ppm, | Harvest Date: | October 11, 2000 |
| K= 77 ppm, Mn= 7 ppm, | |||
| OM=5.3%, CEC=12.4 |
The plot design was a randomized complete block with six replications. Plots were 15 ft. x 50 ft. with a harvest area of 7.5 ft. x 35 ft. The site in north central Fulton County was selected due to a history of Mn deficiency in soybeans. Soil testing showed medium to high for all values tested except for manganese that was in the low range. Foliar manganese was applied on 6/28/00 at R1 (early flower). For treatments with two applications, the second application occurred on 7/12/00 at R2 (late flower). All products were applied in 30 gallons of water per acre.
| Table 1. Complete Product Listing for Study. | |||||
| Product Name |
Company | Formulation | Use Rate per Acre |
Lbs./A Nutient Applied |
Cost/A |
| ElamMax Mn (EM) |
Phosyn | 27% Mn | 0.5 pt | 0.13 Mn | $2.46 |
| Folizyme (Fol) | Stoller | 12%N, 3%K, 3% Ca, 3% Mg |
2 qt | 0.63 N, 0.15 K, 0.15 Ca, 0.15 Mg |
$1.62 |
| Keylate (Key) | Stoller | 5% Mn | 2 pt | 0.06 Mn | $2.86 |
| White Label Mn (WL) |
Stoller | 6% Mn | 2 pt | 0.07 Mn | $1.80 |
| Harvest More Urea Mate (HMUM) |
Stoller | 5% N, 10% P,
27%K, 4% Ca, 1.5% Mg, 0.15% B, 0.008% Co, 0.3% Cu, 0.5% Mn, 0.008% Mo, 0.5% Zn |
5 lbs | 0.25 N, 0.5 P, 1.35 K, 0.2 Ca, 0.075 Mg, 0.0004 Co, 0.015 Cu, 0.025 Mn, 0.0004 Mo, 0.025 Zn |
$4.30 |
| Table 2. Soybean Yield Response to Foliar Fertilizer Applications and Timing. | |||
| Treatment | Application Date & Growth Stage |
Total Actual Mn (lb/A) |
Yield * Bu/A |
| EM | 6/28 (R1) | 0.13 | 38.6 a |
| Fol + WL + Key | 6/28 (R1) | 0.19 | 38.0 a |
| EM | 6/28 (R1) + 7/12 (R2) | 0.26 | 37.5 a |
| WL | 6/28 (R1) + 7/12 (R2) | 0.14 | 36.0 a |
| WL | 6/28 (R1) | 0.07 | 35.4 ab |
| EM + HMUM | 6/28 (R1) | 0.17 | 34.8 ab |
| Check | 0.0 | 27.4 b | |
| * Yields followed by the same letter are not significantly different from each other.
LSD (0.05) = 8.4 bu/A CV = 20.1% |
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Due to a calculation error, the ElamMax Mn+ Harvest More Urea Mate treatment resulted in a 1.6 times over-application of the Urea Mate. Eight pounds per acre were applied instead of the intended five pounds per acre. This did result in foliar burning of the upper leaves which may have decreased yields. There is some margin of safety in these products, since the over-application did not result in a significant yield loss, but growers should be cautious in applications of foliar fertilizer to limit foliar damage.
Observations of foliar color did not vary greatly among any of the treatments. Yellowing from manganese deficiency was more apparent due to difference in plot location than treatment applied.
Manganese is commonly low in availability on higher organic matter soils with pH greater than 7. Yield was significantly greater than the no Mn check in four of the six treatments. There was no significant difference between any two of the foliar fertilizer products.
Area farmers using the ElamMax Mn product experience plugged nozzles when the mix sits overnight in a boom sprayer. For the plot trial, this was not a problem. The manufacturing company is aware of and working on the problem.
For additional information, contact:
Greg La Barge
Ohio State University Extension, Fulton County
135 Courthouse Plaza
Wauseon, OH 43567
labarge.1@osu.edu
419-337-9210