NACHURS K-flex® Max is a versatile liquid fertilizer developed to add readily available potassium, sulfur, and humic acid to starter and in-season fertility programs.
Its concentrated 0-0-16-5S 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, and UAN, which may not provide adequate potassium or sulfur on their own.
K-flex Max is powered by patented NACHURS Bio-K® potassium acetate technology. Bio-K combines potassium with acetate, a natural plant metabolite designed for rapid uptake and greater potassium-use efficiency. This technology supports seed germination, root development, plant establishment, crop vigor, and tolerance to abiotic stress.
The added humic acid supports faster germination, increased root growth, improved nutrient uptake, and healthier soil structure. It also helps improve soil porosity, cation-exchange capacity, and microbial activity within the root zone.
When blended with ammonium polyphosphate, K-flex Max creates a balanced starter fertilizer suitable for planting in cold soils, including minimum-till and no-till environments. When blended with UAN, it can create a potassium-, sulfur-, and humic-acid-enriched strip-till, sidedress, or basal fertilizer program designed to support nitrogen-use efficiency.
Guaranteed Analysis
- Total Nitrogen: 0%
- Available Phosphate: 0%
- Soluble Potash: 16%
- Sulfur: 5%
Primary Nutrient Sources
- Potassium Acetate
- Potassium Thiosulfate
- Humic Acid
Role of Potassium
Potassium works with nitrogen and sulfur to support protein production and proper plant growth. Adding available potassium to a fertility program 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
Role of Sulfur
Sulfur is an essential nutrient for corn and other high-yielding crops. It supports nitrogen metabolism and helps activate nitrate reductase, an enzyme involved in converting nitrates into amino acids.
Adequate early-season sulfur is especially important because deficiencies during young plant development can limit yield potential.
Role of Humic Acid
Humic acid consists of naturally occurring, biologically active organic molecules that are well suited for at-planting and in-season soil applications. Humic acid can help:
- Accelerate germination
- Increase root growth
- Improve nutrient uptake
- Support soil aggregation and structure
- Improve soil porosity
- Increase microbial activity
- Strengthen the root-zone environment
Ideal Applications
- Corn fertility programs
- Starter fertilizer blends
- Cold-soil planting programs
- Minimum-till systems
- No-till systems
- Strip-till applications
- Sidedress nitrogen programs
- Basal fertilizer applications
- UAN fertilizer blends
- Ammonium polyphosphate blends
- Center-pivot fertigation
- Drip-irrigation systems
- Fields requiring additional potassium and sulfur
- Programs focused on nitrogen-use efficiency
- Soil programs benefiting from added humic acid
Starter Fertilizer Use
Add NACHURS K-flex Max directly to 10-34-0 or 11-37-0 to create a more balanced starter fertilizer containing phosphorus, potassium, sulfur, and humic acid.
Maintain continuous agitation or recirculation while mixing, filling, and applying the final solution.
Suggested Starter Blend Ratios
With 10-34-0
Blend 1 gallon of NACHURS K-flex Max with 4 gallons of 10-34-0.
Approximate final analysis: 8-27.2-3.2-1S
With 11-37-0
Blend 1 gallon of NACHURS K-flex Max with 3 gallons of 11-37-0.
Approximate final analysis: 8.2-27.7-4-1.2S
Final analyses are estimates and may vary according to ingredients and mixing methods.
Suggested UAN Blend Ratios
With 28% UAN
Blend 1.25 gallons of NACHURS K-flex Max with 8 gallons of 28% UAN.
Approximate final analysis: 24.2-0-2.1-0.6S
With 32% UAN
Blend 1.25 gallons of NACHURS K-flex Max with 10 gallons of 32% UAN.
Approximate final analysis: 28.4-0-1.7-0.5S
Blend with UAN only at recommended ratios and confirm compatibility before large-scale mixing.
Fertigation Rates
Center-Pivot Irrigation
Apply 1–2 gallons per acre as needed.
Drip Irrigation
Apply 1–2 gallons per application.
Mixing Guidelines
- Fill the tank with approximately half of the required 10-34-0 or 11-37-0.
- Begin agitation or recirculation.
- Add the recommended amount of NACHURS K-flex Max.
- Add the remaining phosphate fertilizer and other compatible products.
- Continue agitation during filling and application.
When blending with UAN below 50°F, add enough water to support thorough mixing. A 1:1 ratio of water to K-flex Max is recommended under these conditions.
Always perform a jar test when combining K-flex Max with anything other than ammonium polyphosphate. Use caution when placing any fertilizer directly with seed because crop injury may occur.
Why Growers Choose NACHURS K-flex Max
Many common starter and nitrogen fertilizers provide phosphorus or nitrogen without supplying adequate potassium and sulfur. NACHURS K-flex Max helps fill those nutritional gaps while adding the root-zone and soil-conditioning benefits of humic acid.
Its compatibility with ammonium polyphosphate and UAN allows growers to create balanced starter, strip-till, sidedress, and basal fertilizer blends without adding another separate application. It also provides flexible options for center-pivot and drip fertigation programs.
K-flex Max should supplement a complete fertility program. Always follow label directions and consult an authorized NACHURS distributor or agronomist for crop- and field-specific recommendations.
Add available potassium. Supply essential sulfur. Strengthen every fertilizer program with K-flex Max. 
