2023 Planning Resources

Clemson Fertilizer Blend Calculator

Released in 2022, this web app calculator was developed to help evaluate different fertilizer blends for meeting nitrogen, phosphorus and potassium requirements in a cost effective and accurate manner.

Calculator outputs depend on user-indicated nutrient application rates as well as fertilizers available. Nutrient requirements are input as nitrogen, phosphorus (P2O5) and potash (K2O). Clemson University Extension recommends using a standard soil test to support the agronomic recommendation of application rates. Fertilizers available are input as a percent composition of N, P2O5, and K2O. 

To determine recommendations for a specific crop, visit the NPK Recommendations Calculator. You can also use the South Carolina soil code, which can be used in conjunction with this web app.

Blend outputs are sorted, beginning with those that best meet the required application rates. If the application rate of any given nutrient fails to meet the target rate, it is flagged for under- and over-application, and the user is alerted. Optionally, if the user provides fertilizer prices, blends that equally satisfy nutrient requirements are sorted by price, beginning with the least expensive, on a per-unit area basis.

The calculator supports two modes of entry. Direct NPK entry allows the user to evaluate blends for a specific application rate. Guided entry provides a worksheet to calculate rates required for a specific application, based on total (seasonal) NPK needs and after deducting other credits, such as litter/manure application, pre-plant application, etc.

The Clemson Fertilizer Blend Calculator and other precision ag calculators can be found here.

Seed Treatments: Start Off On The Right Foot

Seed treatments is a practice of applying pesticides to prevent insects and disease damage to the seeds or seedlings. It can help the crop thrive in early days, minimizing stand loss and sustaining the recommended plant population. 

Seed treatment can be performed on-farm or by the seed dealer, which is convenient to farmers and presents several advantages, such as less risk of intoxication, increased precision of chemical mixtures, an increased amount of seed treated each time and a better seed cover with treatment. Pesticides add some cost to seeds, and producers often have no control as to which products are included in the treatment from a dealer. 

For more information on products to use and their relative efficacy against pests or diseases, consult the Alabama Cooperative Extension Services Integrated Pest Management guides on the ACES website here.

Fungicide Efficacy Ratings

The Corn Disease Working Group developed ratings for how well fungicides control major corn diseases in the United States. The CDWG determined efficacy ratings for each fungicide by field testing the materials over multiple years and locations. Ratings are based on the product’s level of disease control and does not necessarily reflect yield increases obtained from product application. 

A product’s efficacy depends on proper timing, rate and application method as determined by the product label and overall disease level in the field at the time of application. Differences in efficacy among each fungicide product were determined by directly comparing products in field tests using a single application of the labeled rate. For application timing and use considerations, contact your local Extension service.

The Crop Protection Network is a multi-state and international collaboration of university and provincial Extension specialists, and public and private professionals who provide research-based information to farmers and agricultural personnel. Find more crop disease resources here.

Diseases of Corn (courtesy of the Crop Protection Network); click image to zoom

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