Glyphosate Additives on Soybeans

The project assessed the following three foliar fertilizer additives to glyphosate on soybeans:

• “Oligosol Crop Booster”
• “Alpine Fortified”
• “UAP Green With Envy"

One litre/ac (2.4 L/ha) of the foliar fertilizer was added to the 1.0 L/ac (2.4 L/ha) rate of glyphosate and applied at the first to third trifoliate growth stage. 

Results

Observations of the crop after the application of glyphosate plus the foliar fertilizer from the cooperators showed no visible differences in crop colour or growth. Generally no differences in weed control between the treatments was observed. 

The project was only conducted for one year, so that should be taken into consideration when looking at the results. The yields from the main plots and the secondary plots did not show an advantage to the addition of any of the foliar fertilizers (Table 1). The variation in yield of the treated versus untreated was within the range of variability you would expect in these types of plots. 

Middlesex & Elgin Study

The results are similar to the results of a foliar project that the Middlesex and Elgin Soil and Crop Improvement Associations conducted from 1997-1999. A foliar product with a similar nutrient content was applied to soybeans at different crop stages. The average yield on 33 plots for the untreated treatments was 48.3 bu/ac, and the treated yield was 47.3 bu/ac giving a difference of negative one bushel per acre. No yield advantage to the foliar fertilizer application. 

Not a Targeted Approach

The major source of nutrient uptake for plants is through the roots. Generally, soil and tissue samples are analyzed to determine if sufficient levels of nutrients are present in the soil to grow a crop. Any deficiencies are usually corrected with a fertilizer application to the soil. Micro nutrient deficiencies are usually corrected with soil or foliar fertilizer applications depending on the nutrient and the crop. The approach is a targeted one. This project is not based on a targeted approach. Also the time the nutrients were applied is at a stage when the crop does not have much leaf surface area to take up the nutrients. Although the application timing was better with the Middlesex and Elgin project it did not achieve the desired result either. 

The bottom line on the SCDSCIA project is that the product cost of ~$2.50-$5.00 per acre did not return any increased yield. No additional application cost would apply as the product was tank mixed with the glyphosate.

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