Potassium humate is a highly efficient organic potassium fertilizer and soil conditioner produced by combining humic acid with potassium ions. It is widely used in agriculture, oil drilling, environmental protection, and other sectors. Research by the U.S. National Institutes of Health and the University of Hertfordshire (UK) indicates that it improves soil fertility, enhances crop stress resistance, and exhibits low toxicity.
Let us first understand what potassium humate is and what it is used for.
Basic Properties: Potassium humate appears as a black powder or granule and is readily soluble in water, forming an alkaline solution (pH 9–10). It is a mixture of high-molecular-weight organic compounds with a complex actual molecular structure; C9H8K2O4 is a simplified representation.
Agricultural Applications of Potassium Humate:
1. Improves soil aggregate structure and enhances water and nutrient retention capabilities.
2. Increases potassium fertilizer utilization efficiency while reducing potassium loss and fixation.
3. Promotes crop root development and enhances resistance to drought, cold, and disease.
4. Can be applied as a base fertilizer, top dressing, or foliar spray; the typical application rate is 20–25 kg per mu.
Industrial Applications of Potassium Humate:
1. Used as an additive for oil drilling mud to prevent borehole wall collapse.
2. Used for ceramic slurry modification, boiler scale prevention, and heavy metal wastewater treatment.
3. Used as an additive for battery plates, a binding agent, etc.
Safety: The product is non-toxic, odorless, and has low ecotoxicity, posing minimal risk to humans and the environment; however, it should be used according to guidelines to avoid excessive application.
What is the difference between potassium humate and potassium fulvate?
Potassium humate and potassium fulvate are not the same product; potassium fulvate is a highly purified form of humic acid. The key differences between the two are as follows:
1. Solubility: Potassium humate has relatively poor water solubility and tends to precipitate if left to stand, making it unsuitable for drip irrigation or foliar spraying; potassium fulvate is 100% water-soluble and compatible with integrated water-and-fertilizer systems. 2. Molecular Weight and Activity: Potassium humate has a high molecular weight and low activity; it acts slowly and serves as a long-term soil conditioner. Potassium fulvate has a very low molecular weight and an activity level 8–10 times that of ordinary humic acid, allowing for rapid absorption and quick results.
3. Core Functions: Potassium humate focuses primarily on soil improvement and soil health maintenance. Potassium fulvate offers dual benefits—soil maintenance and growth promotion—with particularly strong effects on root development, quality enhancement, and yield increases.
4. Application Scenarios: Potassium humate is suitable for basal application before sowing or broadcasting during tillage. Potassium fulvate is suitable for use throughout the entire growth cycle and can be applied via fertigation (irrigation injection), drip irrigation, or foliar spraying.
5. Price: Potassium humate raw materials are readily available and inexpensive. Potassium fulvate requires purification and activation, resulting in a higher price, though it requires lower application rates and offers high utilization efficiency.
Application Methods for Potassium Humate:
1. Proper Application Techniques:
It can be used as a top-dressing or basal fertilizer; application methods include banding, broadcasting, and hole application.
For foliar spraying, use a 0.1%–0.2% solution (1,000-fold dilution); for root drenching, use a 500-fold diluted aqueous solution.
The diluted solution is highly alkaline; if the pH exceeds 8, adjust it to 7–8 using a small amount of dilute hydrochloric acid before application.
Avoid spraying at noon under high temperatures and intense sunlight; discontinue use if temperatures exceed 38°C.
2. Dosage Control:
The application rate is generally 20–25 kg per mu; do not exceed this amount.
Excessive use can cause nutrient antagonism, inhibiting the crop’s absorption of calcium, magnesium, and phosphorus, which may lead to leggy growth and the dropping of flowers and fruit.
Potassium humate cannot replace organic fertilizer; it should be used in conjunction with organic fertilizer.
3. Mixing Precautions:
Do not mix with strongly alkaline pesticides or fertilizers, as this will cause neutralization, loss of efficacy, and precipitation.
Strictly avoid mixing potassium fulvate directly with calcium-magnesium-phosphate fertilizers, calcium nitrate, or calcium/magnesium-containing medium/micro-element preparations; doing so will produce flocculent precipitates that can clog drip irrigation lines. Prepare for immediate use after dissolving; if the solution is left to stand in water for more than 12 hours, it will lose activity and its nutrients will degrade.
