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The PhytoGen Cotton Development Specialist (CDS) team has researched the economic and agronomic benefits of dialing in fertilizer applications.

Fertilizer costs continue to be top of mind for farmers. The good news is we can help.

Many producers can improve fertilizer use in cotton. Farmers correlate applied nitrogen (N) to yield potential, but N often is not the yield-limiting factor — and overapplication can create problems. With high fertilizer prices, it’s important to hit the sweet spot.

Often overlooked, potassium (K) is another critical plant nutrient that aids water uptake, increases nutrient usage and improves drought tolerance. K also promotes protein production, increasing leaf growth and yield potential.

It’s important to get fertility right early in the season. It’s harder to correct a deficiency once symptoms appear. Soil testing is critical to understand fertility requirements so growers can address deficiencies early.

The PhytoGen Cotton Development Specialist (CDS) team has researched the economic and agronomic benefits of dialing in fertilizer applications.

Save unnecessary inputs, maximize production and protect profits by following these key practices:

  • Don’t overapply N fertilizer. Our data shows little yield response to more than 100 units/A of N. Excess N increases input costs, promotes rank growth and boll rot, lengthens maturity, complicates defoliation, and can reduce cotton yields.
  • Increase K fertility levels with savings from N reductions. K is essential for boll and fiber development. Our data shows increasing available K to 120 units/A maximizes lint yield and promotes increased fiber quality, especially length.
  • Pay attention to sulfur (S) levels. S in cotton soils is decreasing from a lack of atmospheric deposition and typically low organic matter.
  • Add lime to soils for a target pH of 6.0 to 6.5 for optimum availability of soil nutrients.
  • Look for boron (B) deficiencies in recently limed soils. B aids in the utilization of N and K in the plant and helps promote boll set. Deficiencies are likely to occur in recently limed soils or where pH is above 6.5. If needed, apply 0.5 pound of B in a dry blend with other nutrients.

The PhytoGen CDS team has studied the impact of fertility on cotton. Below is a graph from Jonathan Siebert, Ph.D., that shows the "sweet spot" for N and K levels. Our data suggests little additional yield response to N fertilization over 100 units/A. On the other hand, increasing K (potash) to 120 units/A maximized lint yield.

Our CDS team also has researched specific variety considerations related to fertility. For example, PhytoGen® brand PHY 400 W3FE requires sufficient potash or leaves will develop severe speckling later in the season. See the photos below, which show varying leaf speckling according to potash levels in PHY 400 W3FE and PhytoGen brand PHY 411 W3FE.

With high fertility prices, you have an opportunity to maximize input investment with PhytoGen® cottonseed.

While N still provides a positive return on investment, the risk associated with rank growth, delayed maturity, boll rot and potential reduced yields indicates spending money on additional K fertilizer is a better use of input resources.

Contact your local CDS to get more information on fertility recommendations for your region.

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