Source: John Grove, Department of Plant and Soil Sciences professor

Proper fertilizer usage is essential for achieving high crop yields and farm profitability while maintaining soil health.

The Importance of Soil Testing

Soil testing is the foundation of effective nutrient management. The process involves collecting soil cores from 15-20 locations within a field/field area, to a specific depth. This method ensures that the samples are representative of the entire area, providing more accurate data on nutrient levels and soil pH.

Lime Application for Soil Health

Producers should apply lime based on soil test results to ensure that the soil pH is within the optimal range for their crops. By adjusting the soil pH, lime application can enhance nutrient uptake and improve overall soil health.

Fertilizer Recommendations for Various Crops

Different crops have varying nutrient requirements, and it is important to tailor fertilizer applications accordingly. Here are some specific recommendations for major crops grown in Kentucky:

Corn

Corn requires significant amounts of nitrogen, phosphorus and potassium for optimal growth. Soil testing can determine the exact nutrient needs, but general guidelines suggest applying nitrogen in split applications: a portion at planting and the remainder during the growing season. Phosphorus and potassium should be applied before/at planting, based on soil test results, to ensure adequate nutrition throughout the growing period.

Soybeans

Soybean, being a legume, can fix atmospheric nitrogen through a symbiotic relationship with a soil bacterial species. However, the crop still requires adequate phosphorus and potassium. Soil tests help determine appropriate application rates for these nutrients. Phosphorus and potassium for soybean should also be applied before/at planting.

Wheat

Wheat benefits from nitrogen, phosphorus and potassium applications. Sufficient wheat nitrogen nutrition may benefit from multiple splits: a small amount at planting, followed by additional applications just prior to/during tillering and another at early stem elongation. Phosphorus and potassium should be applied according to soil test results, before/at planting.

Tobacco

Tobacco has high nutrient demands, particularly for nitrogen and potassium. Nitrogen should be applied in split applications: a portion at planting and the remainder during the growing season. Potassium is critical for tobacco quality and should be applied according to soil test recommendations. Adequate phosphorus is also necessary, and both phosphorus and potassium are applied before/at planting, based on soil test results.

Benefits of Proper Fertilizer Usage

Following these fertilizer recommendations offers several benefits to farmers:

1. Improved Crop Yields: By providing crops with the right nutrients at the right times, farmers can achieve higher yields and a better-quality product.
2. Enhanced Soil Health: Proper nutrient management maintains soil fertility, ensuring long-term productivity.
3. Cost Efficiency: Applying fertilizers based on soil test results prevents both under and over application, optimizing yields and input costs while minimizing environmental impacts.
4. Sustainable Practices: Efficient fertilizer use supports sustainable farming by optimizing resource use and preserving soil quality for future generations.

Effective fertilizer use is crucial for successful crop production. By conducting regular soil tests and following crop-specific nutrient recommendations, growers can optimize their fertilizer applications. This approach not only enhances crop yields and soil health but also promotes sustainable farming practices. With careful management, producers can achieve productive and sustainable agricultural systems.

For more information, visit the University of Kentucky Martin-Gatton College of Agriculture, Food and Environment recommendation publication at https://www2.ca.uky.edu/agcomm/pubs/AGR/AGR1/AGR1.pdf.

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