Mastering Water-Soluble Fertilizers: Tips from an Agronomist

Water-soluble fertilizers (WSFs) are key players in precision agriculture, allowing growers to apply nutrients exactly where and when crops need them. In this Q&A guide, we’ll tackle common questions about selecting and using WSFs to achieve the best results. With agronomy insights on everything from product compatibility to application timing, we explore how to make the most of WSFs for increased crop yield and efficiency.

Q: Why are water-soluble fertilizers becoming more popular in today’s agricultural practices?

A: Water-soluble fertilizers allow precise, targeted delivery of nutrients, especially when used in fertigation systems (applying fertilizers through irrigation) or for foliar feeding. Here’s why they’re a great choice:

• Improved Nutrient Efficiency: WSFs can reduce nutrient loss and waste by focusing application directly on crop roots or leaves.
• Flexibility: WSFs can be customized by crop stage and nutrient demand, whether for rapid early growth or fruiting stages.
• Enhanced Crop Performance: Precision delivery of nutrients when and where the crop needs them leads to better growth, yield, and overall plant health.

For example, a high-phosphorus WSF like Agrolution® pHLow (11-45-11) with zinc supports root growth in early stages, while a potassium-rich option, such as Nova HiPeak® (0-44-44), enhances fruit size and quality later in the season.

Q: What should I consider when choosing a water-soluble fertilizer?

A: Choosing the right WSF involves understanding your crop’s nutrient needs and environmental conditions. Key considerations include:

• Nutrient Ratios: Match the formulation to the crop’s growth stage. Early growth often needs more phosphorus, while potassium is critical during fruiting/reproduction.
• Water Quality: Factors like pH and bicarbonate levels can impact WSF solubility and nutrient availability.
• Application Method: Fertigation requires different characteristics than foliar feeding.

For instance, a product with a low pH, like Nova PeKacid® (0-60-20), can help prevent clogging in drip systems while enhancing phosphorus availability. Tip: Regularly test your water quality. High-pH water can lead to nutrient lockout, so choosing an acid-forming WSF may be beneficial.

Q: How does water quality and irrigation system type affect water-soluble fertilizer performance?

A: Water quality, especially pH and bicarbonate levels, directly affects WSF performance in irrigation systems. In high-pH or “hard” water (often with high calcium or bicarbonate), certain nutrients can form insoluble compounds, leading to clogging and nutrient lockout.

• Acidifying WSFs: Using an acid-forming fertilizer, such as Nova PeKacid® (0-60-20), or Agrolution pHLow®, which lowers pH levels in the irrigation water and the root zone, keeping nutrients in solution and prevents clogging.
• Compatibility with Drip and Micro-sprinkler Systems: These systems require a low risk of precipitation to keep emitters unclogged. Acid-forming WSFs prevent mineral buildup in such systems, improving nutrient availability and water flow efficiency.

Q: Should WSFs be used to apply micronutrients, and if so, what’s the best approach?

A: Yes, water-soluble fertilizers are excellent for delivering micronutrients, especially through foliar feeding. Micronutrients like zinc, boron, and manganese are crucial in small amounts for crop health, but because they can be sensitive to soil binding and pH issues, WSFs make it easier to control their availability.

• Foliar Application for Quick Uptake: Applying micronutrient-enriched WSFs like Nova PULSE®, which includes phosphorus, potassium, and essential micronutrients, directly to leaves can quickly address nutrient needs across all crops to enhance yield potential. Nova ELEVATE™ (1.2 Co + 26 Mo) is a unique N-P-K free formula that contains high amounts of Molybdenum to help improve nitrogen use efficiency and retain fruit/nuts. Especially suited for crops with high trace element demands, it is also a good fit for high-value specialty crops like almonds, fruit orchards and berries
• Chelated Micronutrient Formulations: Some micronutrients are more effective when chelated, like our Agrolution and Agrolution pHLow lines, which protects them from soil interactions that could reduce availability and can help with leaf absorption. Nova FINISH (8-12-40 + micros) for example, contains a fully chelated EDTA micronutrient package and is free from chloride and urea while also providing a boost of potassium.

Tip: To ensure compatibility and effectiveness, use micronutrient WSFs with surfactants or biostimulants or enhanced nutrient fertilizers for even better uptake. Always conduct a jar test before mixing WSFs with other products in foliar applications.

Q: Why would I choose a water-soluble fertilizer over a liquid fertilizer?

A: While liquid fertilizers are popular for their ease of use in large-scale irrigation, simplified handling, and versatility in nutrient formulations, water-soluble fertilizers offer additional benefits. With ICL’s expanded product line, including Nova products in dry, water-soluble, and concentrated liquid forms, growers can select the option that best suits their operational needs. Water-soluble fertilizers can provide precise nutrient delivery, are compatible with various application methods, and allow for control over nutrient uptake, which can enhance crop productivity and yield. ICL’s product variety helps optimize agricultural practices, ensuring growers have the right solution for their specific requirements.

Q: How should WSFs be applied in fertigation versus foliar feeding?

A: The application method can determine the best product and concentration for WSFs:

• Fertigation: Ideal for steady, season-long nutrient delivery through drip or sprinkler systems. A product like Nova HiPeak® (0-44-44) provides potassium and phosphorus with a neutral pH, making it suitable for ongoing fertigation.
• Foliar Feeding: Used for quick nutrient uptake, foliar applications are especially useful during periods of nutrient deficiency or key growth stages. For example, Nova HiPeak® (0-44-44) works well as a foliar feed in fruiting crops, offering potassium without altering the pH. Other foliars can be used to supply specific micronutrients (Nova ELEVATE) or address high-demand potassium needs later in the season (Nova FINISH).

Tip: Use a product compatible with your crop protection chemistries if you’re combining WSFs with pesticides. For foliar applications, choose a formula that won’t alter the pH significantly if sensitive products are being applied together.

Q: Are there any water-soluble fertilizer products you recommend for common crop needs?

A: Here are some WSF products that perform well across a range of crops:

• Nova PeKacid® (0-60-20): Ideal for high-pH water, providing phosphorus and potassium while lowering pH to improve nutrient uptake, used with great success in a wide range of row and specialty crops.
• Nova HiPeak® (0-44-44): A balanced phosphorus and potassium product that’s excellent for both fertigation and foliar feeding, especially for fruiting crops like apples.
• Agrolution® pHLow™ (11-45-11) with Zinc: Great for early stages to encourage strong root development in crops like corn, soybean, and wheat.

Making Every Drop Count

Water-soluble fertilizers offer powerful tools for precise, efficient crop nutrition, provided they’re selected and applied correctly. From understanding water quality to choosing the right nutrient balance for each growth stage, these best practices can help farmers maximize yield, minimize waste, and improve overall crop quality. Have more questions? Contact an ICL expert – we’re here to help.