By Brian Cornelious, PhD, Agricen
The use of starter fertilizer, aimed at getting plant nutrients in a concentrated zone close to the point of seed placement, is a common practice in some parts of the country.
A standard starter program for corn in the U.S. Corn Belt is 3-5 gallons of ammonium polyphosphate (10-34-0) plus 1 quart of zinc per acre. More progressive growers have gravitated towards readily available orthosphosphate blends containing micronutrients or other enhancements like biostimulants. Regardless of the rate, timing, source and amount (the “4Rs”) of the practice, the goal is the same: Get the most out of every nutrient applied for better early growth and development.
Conversion from polyphosphate to plant-available orthophosphate takes place in the soil, where microbes and soil chemistry both play a role in making the applied and existing soil nutrients available to the plant, as well as in the timing of nutrient release into the soil solution. For any liquid starter program to be successful, growers must consider several key factors like soil test values, crop yield goals, field conditions and potential for nutrient release when the crop needs them most.