NACHURS K-flex® is a versatile liquid potassium and sulfur fertilizer developed to supplement starter, sidedress, foliar, and fertigation programs throughout the growing season.
Its concentrated 0-0-19-6S formulation supplies soluble potassium and sulfur derived from potassium acetate and potassium thiosulfate. These nutrients complement common phosphate and nitrogen fertilizers such as 10-34-0, 11-37-0, UAN, and liquid urea, which may not supply enough potassium or sulfur to meet the requirements of high-yielding crops.
K-flex is powered by patented NACHURS Bio-K® potassium acetate technology. Bio-K combines potassium with acetate, a natural plant metabolite designed for rapid plant uptake and improved potassium-use efficiency. This technology supports quicker germination, improved root development, stronger crop establishment, greater plant vigor, and increased tolerance to abiotic stress.
When added to ammonium polyphosphate, K-flex creates a more balanced starter fertilizer for planting in cold soils, including minimum-till and no-till systems. When blended with UAN, it provides supplemental potassium and sulfur during strip-till and sidedress applications when crop uptake of these nutrients is increasing rapidly.
K-flex can also be applied alone or blended with liquid urea to create an effective foliar fertilizer for forage crops, legumes, small grains, and other compatible crops.
Guaranteed Analysis
- Total Nitrogen: 0%
- Available Phosphate: 0%
- Soluble Potash: 19%
- Sulfur: 6%
Primary Nutrient Sources
- Potassium Acetate
- Potassium Thiosulfate
Role of Potassium
Potassium works with nitrogen and sulfur to support protein production and healthy crop growth. Adequate available potassium can help:
- Increase drought resistance
- Develop stronger stalks and stems
- Maintain healthy plant metabolism
- Support photosynthesis
- Improve nutrient and carbohydrate movement
- Increase protein and starch formation
- Support natural plant defenses
A high soil-test potassium level does not always mean that enough potassium will be available during periods of peak crop demand.
Role of Sulfur
Sulfur is an essential nutrient for corn and other high-yielding crops. It supports nitrogen metabolism and activates nitrate reductase, an enzyme that helps convert nitrates into amino acids.
Early-season sulfur availability is particularly important because deficiencies during young plant development can reduce yield potential.
Ideal Applications
- Corn
- Forage crops
- Legumes
- Small grains
- Row crops
- Specialty crops
- Trees and vines
- Vegetable crops
- Starter fertilizer blends
- Cold-soil planting programs
- Minimum-till and no-till systems
- Strip-till applications
- Sidedress nitrogen programs
- Foliar nutrition programs
- Center-pivot fertigation
- Sprinkler irrigation
- Drip-irrigation systems
- Fields requiring additional potassium or sulfur
General Blend Rates
Blend 1 gallon per acre of NACHURS K-flex with:
- 4 gallons per acre of 10-34-0 for a starter application
- 3 gallons per acre of 11-37-0 for a starter application
- 8 gallons per acre of 28% UAN for strip-till or sidedress
- 10 gallons per acre of 32% UAN for strip-till or sidedress
- 2 gallons per acre of 21-0-0 liquid urea for foliar application
Suggested Starter Blends
With 10-34-0
Blend 1 gallon of K-flex with 4 gallons of 10-34-0.
Approximate final analysis: 8-27-3-1S
With 11-37-0
Blend 1 gallon of K-flex with 3 gallons of 11-37-0.
Approximate final analysis: 8-28-4-1.5S
Suggested Sidedress Blends
With 28% UAN
Blend 1 gallon of K-flex with 8 gallons of 28% UAN.
Approximate final analysis: 25-0-2-0.7S
With 32% UAN
Blend 1 gallon of K-flex with 10 gallons of 32% UAN.
Approximate final analysis: 29-0-1.7-0.5S
Suggested Foliar Blend
Blend 1 gallon of K-flex with 2 gallons of 21-0-0 liquid urea.
Approximate final analysis: 14-0-6-2S
Final blend analyses are estimates and may vary according to ingredients and mixing methods.
Foliar Application Rates
Row Crops
Apply 2–8 quarts per acre with 3–10 gallons of water using ground or aerial equipment.
Specialty Crops
Apply up to 4 quarts per acre for every 100 gallons of water.
Fertigation Rates
Center-Pivot Irrigation
Apply 0.5–5 gallons per acre as needed.
Sprinkler Irrigation
Apply 0.5–5 gallons per acre to trees, row crops, and vegetables.
Apply 0.5–4 gallons per acre to vines.
Drip Irrigation
Apply 0.5–5 gallons per application.
Mixing Guidelines
- Fill the tank with approximately half of the required water, phosphate fertilizer, or other compatible material.
- Begin agitation or recirculation.
- Add the recommended amount of NACHURS K-flex.
- Add the remaining materials and other compatible products.
- Maintain agitation throughout filling and application.
When blending with UAN below 50°F, add sufficient water to ensure complete mixing. A 1:1 ratio of water to K-flex is recommended under these conditions.
Always perform a jar test when combining K-flex with anything other than ammonium polyphosphate. Use caution when placing fertilizer directly with seed because crop injury may occur.
Why Growers Choose NACHURS K-flex
Higher crop yields can remove potassium from the soil faster than it is replaced. At the same time, common phosphorus and nitrogen fertilizers may not supply enough potassium or sulfur during critical periods of crop growth.
NACHURS K-flex gives growers a flexible way to add these nutrients to starter, sidedress, foliar, and irrigation applications. Its compatibility with phosphate fertilizers, UAN, and liquid urea makes it easier to build balanced fertility treatments without requiring an additional field pass.
K-flex should supplement a complete fertility program. Always follow label directions and consult an authorized NACHURS distributor or agronomist for crop- and field-specific recommendations.
Supply critical potassium. Deliver essential sulfur. Build more balanced fertility with K-flex. 
