Does Your Liquid Starter Fertilizer for Corn Provide Enough Zinc?By Wolf Trax
Most farmers have become aware of the importance of zinc nutrition to high-yielding corn. Many farmers who apply a liquid starter fertilizer for corn off the planter have included zinc in the mix. Recent trial work in South Dakota suggests, however, there might not be enough zinc in most starter fertilizers for fields with low soil zinc levels.
How Much Zinc Does Corn Need?
For a 200-bushel corn crop, total crop usage of zinc is 0.39 lbs/acre. More than half of that – 0.24 lbs/acre – goes into the grain and will be removed the field at harvest.
If you’re growing more than 200-bushel corn, both numbers will be higher. If you’re removing stover from the field for feed or energy, you should plan to replenish more zinc closer to the total crop usage figure.
How Much Zinc is in Liquid Starter Fertilizers for Corn?
Many liquid starter fertilizers provide less than 0.2 lbs elemental zinc/acre. This amount is less than grain removal for a 200-bushel corn crop. If the liquid starter is the only zinc fertilizer source for your field, you may not be replenishing the crop removal rate. Eventually you will most likely be drawing down your soil’s zinc levels.
Do I Need to Supplement the Zinc in my Liquid Starter?
It’s important to know your soils. Traditionally soil zinc deficiencies were common in the western Corn Belt. Soil test summaries from the International Plant Nutrition Institute suggest, however, that zinc nutrient levels are being neglected in many corn-growing states.
Last year more than half of all the soil tests analyzed for Indiana, Iowa, Kentucky, Ohio, South Dakota and Tennessee showed low zinc levels.
If your soil test results show low zinc, you should plan to apply more than the amount that the crop removes. If the elemental zinc content of your liquid starter for corn is 0.2 lbs/acre or less, relying solely on the liquid starter as your zinc fertilizer source could hold back corn yield.
How Can I Increase My Zinc Rates?
Evaluating ROI is critical, and adding more zinc to your liquid starter can be expensive. A better option is to supplement your starter with Wolf Trax Zinc DDP® coated onto your dry fertilizer.
In 2015, an independent group in South Dakota conducted research comparing fertilizer sources. The grower’s standard practice was to add a liquid micronutrient mix, which included zinc, to the liquid N-P-K starter fertilizer he applies in-furrow off the corn planter. The yield was satisfactory, and the farmer would probably have been happy with the result.
But when the trial supplemented the liquid micronutrients in the starter fertilizer by coating the dry N-P-K blend with Wolf Trax DDP Nutrients, yield and ROI increased significantly.*Net Revenue is calculated by subtracting the input costs of the in-furrow micronutrients and/or Wolf Trax DDP Nutrients from the gross revenue.
Improve Your Crop’s Performance and ROI
With EvenCoat™ Technology, Wolf Trax Zinc DDP® coats onto dry fertilizer granules during the blending process. This delivery system provides blanket-like distribution of zinc fertilizer for corn in the field and places zinc closer to plants roots for earlier uptake.
What yield and margin opportunities could you be missing out on? Evaluate your soil nutrient levels, and look into the zinc content of your liquid starter. If your fields have low zinc levels, an in-furrow application of only 0.1 to 0.2 lbs elemental zinc/acre may not be providing adequate zinc. You could be missing out on a profit opportunity.
Ask your fertilizer retailer to add Wolf Trax Zinc DDP to your fall P-K blend or your spring pre-plant fertilizer. Tweet us your questions at @WolfTraxInc or comment on this blog.
 University of Illinois, 2010.