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Monoammonium Phosphate Fertilizer 12-61-0

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Weight: 2 Pounds

Monoammonium Phosphate (MAP) 12-61-0 Water-Soluble Fertilizer

Professional-grade water-soluble MAP delivering an industry-leading 61% phosphorus for exceptional flowering, fruiting, and root development. Dissolves completely for drip irrigation, fertigation, hydroponics, and foliar applications — unlike granular MAP, which is for soil use only.

🧪 CDFA Registered 🇺🇸 Made in USA 🛡️ 90-Day Guarantee 🚚 Free Shipping $100+

Ideal Applications

Drip Irrigation
1–2 lbs per 100 gallons
Hydroponics
0.5–1.0 g per gallon
Foliar Spray
1–2 tbsp per gallon
Flowering Stage
Increase rates 2 weeks before bloom
Field & Garden
1–4 lbs per 100 sq ft
Commercial Crops
20–80 lbs per acre
FEATURES

🏆 Industry-Leading 61% Phosphorus

At 61% P₂O₅, this water-soluble MAP delivers more available phosphorus per pound than virtually any other commercial fertilizer, maximizing return on every application.

💧 100% Water-Soluble Powder

Dissolves completely with no residue — safe for drip lines, injectors, and foggers. Unlike granular MAP 11-52-0, this technical-grade powder is engineered for liquid feed systems.

🌸 Bloom & Fruit Set Support

High phosphorus drives ATP energy transfer, flower initiation, bud formation, and fruit set — making MAP 12-61-0 the go-to choice for the transition into reproductive growth.

🌱 Deep Root Development

Phosphorus is critical for cell division and root elongation. Early-season MAP applications establish strong root architecture that supports the entire growing cycle.

⚗️ pH-Lowering Effect

MAP solutions have a pH of approximately 4.5, making this fertilizer ideal for alkaline soils and hard irrigation water where phosphorus availability is often limited by high pH.

🔬 Tested for Heavy Metals

Independently lab tested for heavy metal content to ensure crop purity and environmental safety. Technical-grade purity exceeds agricultural-grade MAP in dissolved clarity and consistency.

🌿 Hydroponic Compatible

A primary phosphorus source in hydroponic nutrient solutions. Compatible with most hydroponic nutrients at 0.5–1.0 g per gallon — adjust pH after addition as MAP is acidic.

🧪 CDFA Registered

Registered with the California Department of Food and Agriculture. Meets all labeling and analytical requirements for commercial fertilizer sale and use in California and nationwide.

🎯 Precision Fertigation

Dissolves at 1–2 lbs per 100 gallons for injection through drip systems. Delivers phosphorus directly to the root zone with no soil tie-up or granule breakdown lag time.

🌍 Reduced Environmental Impact

Precise liquid delivery minimizes phosphorus runoff versus broadcast granular application. Targeted fertigation means less product used, less leaching, and more efficient uptake.

DERIVED FROM

Greenway Biotech sources technical-grade monoammonium phosphate produced by the controlled reaction of high-purity ammonia with food/technical-grade phosphoric acid. The result is a clean, white crystalline powder with superior solubility compared to agricultural-grade granular MAP.

Primary Source

Technical Grade Monoammonium Phosphate (NH₄H₂PO₄)

Water-soluble powder grade — distinct from agricultural granular MAP 11-52-0, which does not dissolve and is intended for direct soil incorporation only. This technical grade is manufactured to higher purity standards for use in liquid feed systems, hydroponics, and foliar applications.

SCIENCE BEHIND THE FORMULA

12-61-0: Maximum Phosphorus, Immediate Availability

MAP 12-61-0 is formulated for applications where rapid, high-concentration phosphorus delivery is required. The 12% ammoniacal nitrogen works synergistically — the acidifying effect of ammonium lowers rhizosphere pH, which directly increases phosphorus solubility and uptake efficiency at the root surface.

🌿 Nitrogen — 12% (Ammoniacal)

All nitrogen is in ammonium (NH₄⁺) form — immediately available and taken up alongside phosphate ions. Ammonium also acidifies the root zone, enhancing phosphorus release from soil particles and improving overall micronutrient availability.

🌸 Phosphorus — 61% P₂O₅

Among the highest phosphorus concentrations available in any water-soluble fertilizer. Phosphorus drives ATP energy production, cell division, DNA synthesis, and the signaling cascades that initiate flowering and fruit development.

⚖️ Potassium — 0%

MAP contains no potassium, allowing growers to supply phosphorus independently without altering potassium ratios. Pair with MKP 0-52-34 or Potassium Sulfate to complete a balanced program.

Why Water-Soluble MAP Outperforms Granular for Liquid Systems

⚡ Immediate Availability

No granule breakdown required. Dissolved MAP delivers phosphate ions directly to roots on contact — critical during the narrow flowering window where phosphorus demand peaks within days.

🎯 System-Safe Chemistry

Technical-grade purity means no insoluble fillers that clog emitters or injectors. Granular MAP 11-52-0 contains binders and coatings that make it unsuitable for any liquid delivery system.

📊 Precise Dosing

Dissolve by weight for exact PPM targeting. Hydroponic and fertigation growers can maintain 150–200 ppm phosphorus in solution with consistent, measurable accuracy not possible with granular products.

APPLICATION RATES & DIRECTIONS

Field & Garden — Vegetative Stage

Area Application Rate Frequency
Per 100 square feet 1–2 lbs Every 4–6 weeks
Per Acre 20–40 lbs During growing season
Container Plants (5 gal) 1–2 tablespoons Every 2–3 weeks

Field & Garden — Flowering & Fruiting Stage

Area Application Rate Frequency
Per 100 square feet 2–4 lbs Every 4–6 weeks
Per Acre 40–80 lbs As needed
Container Plants (5 gal) 2–3 tablespoons Every 2 weeks

Liquid Application Methods

Method Rate Best For
Drip Irrigation / Fertigation 1–2 lbs per 100 gallons Vegetables, orchards, commercial crops
Foliar Spray 1–2 tbsp per gallon Quick correction, transitional feeding
Hydroponics 0.5–1.0 g per gallon; maintain 150–200 ppm P Soilless systems — adjust pH after addition
Broadcasting (dissolved) Dissolve, then apply 1–2 lbs per 100 sq ft Field crops, lawns
⚠️ Note: This is a water-soluble powder. Always dissolve fully before use. Do not apply dry granules to liquid systems. For dry soil broadcasting, see MAP 11-52-0 Granular.
HOW TO USE

Drip Irrigation & Fertigation

  1. Weigh the required amount using a kitchen or postal scale for accuracy.
  2. Pre-dissolve MAP in a small volume of warm water, stirring until fully clear.
  3. Add dissolved solution to your injection tank or stock reservoir.
  4. Inject at 1–2 lbs per 100 gallons of irrigation water.
  5. Flush the system briefly with plain water after each fertigation cycle to prevent line buildup.

Hydroponics

  1. Weigh 0.5–1.0 grams per gallon of final nutrient solution volume.
  2. Dissolve in a small amount of water before adding to reservoir.
  3. Add to reservoir alongside other nutrients — add MAP before calcium-containing products to avoid precipitation.
  4. Measure pH after all nutrients are added and adjust to target range (5.5–6.5 for most crops).
  5. Monitor EC — MAP will increase conductivity. Measure before and after addition.

Foliar Spray

  1. Mix 1–2 tablespoons per gallon of water.
  2. Optionally add a surfactant for better leaf coverage.
  3. Spray early morning or late evening to minimize evaporation and leaf burn risk.
  4. Avoid applying during active flowering — spray vegetative tissue only.
  5. Repeat every 2–4 weeks as needed for quick phosphorus correction.

Soil & Garden Beds (Dissolved)

  1. Dissolve 1–4 lbs per 100 sq ft in water before application.
  2. Apply as a soil drench, watering evenly across the root zone.
  3. For pre-plant applications, apply 2–4 weeks before transplanting.
  4. Reapply every 4–6 weeks during the growing season, increasing rates at flowering onset.

Pro Tip: Time Your Peak Application

For flowering vegetables and fruits, begin increasing MAP rates 1–2 weeks before expected bloom. Phosphorus needs to be present in plant tissue before flowering begins — waiting until you see flowers means the window for maximum fruit set support has already partially closed.

When MAP 12-61-0 Is the Right Choice

  • You're feeding through drip irrigation, injectors, or a fertigation system
  • You're growing hydroponically and need a precise phosphorus source
  • Your soil or water pH is above 7.0 and phosphorus availability is reduced
  • Plants are showing phosphorus deficiency (purple/reddish leaf undersides)
  • You're transitioning crops into the flowering or fruiting stage
  • You need foliar phosphorus correction quickly

When to Consider Other Options

  • You're broadcasting dry fertilizer across a field or lawn — use MAP 11-52-0 Granular instead, which is more economical for soil incorporation
  • You need potassium alongside phosphorus — consider MKP 0-52-34 which provides both P and K
  • You need a slow-release phosphorus option — Bone Meal 3-15-0 provides gentler, longer-lasting release for established plantings
MAP 12-61-0 CALCULATOR
SAFETY & HANDLING
Personal Protective Equipment (PPE)
  • Wear chemical-resistant gloves when handling concentrated powder or solutions
  • Use safety glasses or goggles — fine powder can irritate eyes
  • Wear a dust mask when measuring or pouring to avoid inhaling fine particles
  • Wash hands thoroughly with soap and water after handling
Storage Guidelines
  • Store in a cool, dry location in the original sealed container
  • MAP is hygroscopic — exposure to humidity will cause caking; reseal tightly after each use
  • Keep away from direct sunlight and heat sources
  • Store away from children and pets
  • Do not store near incompatible materials (calcium-containing fertilizers, strong oxidizers)
Application Precautions
  • Do not mix concentrated MAP solution directly with calcium nitrate — precipitate will form; dilute separately before combining
  • MAP solution is acidic (pH ~4.5) — handle with care and avoid contact with skin and eyes
  • Avoid foliar application during flowering or in temperatures above 90°F to prevent leaf burn
  • Do not exceed recommended rates — excess phosphorus can lock out zinc, iron, and other micronutrients
  • Follow all local regulations regarding fertilizer application near waterways
First Aid
  • Eye contact: Flush with clean water for 15 minutes. Seek medical attention if irritation persists
  • Skin contact: Wash affected area with soap and water
  • Ingestion: Do not induce vomiting. Contact Poison Control (1-800-222-1222) or seek medical attention
  • Inhalation: Move to fresh air. Seek medical attention if symptoms persist

Refer to the Safety Data Sheet (SDS) for complete safety information.

COMPLETE YOUR SYSTEM
FREQUENTLY ASKED QUESTIONS
What is the difference between MAP 12-61-0 and MAP 11-52-0?

These are two different grades of monoammonium phosphate for different applications. MAP 12-61-0 is a technical-grade water-soluble powder that dissolves completely in water — it is designed for drip irrigation, fertigation, hydroponics, and foliar spray. MAP 11-52-0 is an agricultural-grade granular product for direct soil application only; it does not dissolve and will clog liquid delivery systems if you attempt to use it that way.

In terms of nutrient content, MAP 12-61-0 has slightly higher phosphorus (61% vs. 52%) and slightly lower nitrogen (12% vs. 11%) than the granular grade. Choose 12-61-0 for any liquid feed program, and MAP 11-52-0 for broadcasting or incorporating into soil.

Why does MAP 12-61-0 lower solution pH, and is that a problem?

MAP solutions have a pH of approximately 4.5 due to the acidic nature of monoammonium phosphate. In most cases this is actually beneficial — it helps dissolve calcium carbonate scale in hard water, improves phosphorus availability in alkaline soils (pH above 7.0), and keeps nutrients in their plant-available ionic form in the solution.

In hydroponics, monitor your reservoir pH after adding MAP and adjust back to your target range (typically 5.5–6.5). In drip fertigation, the final dilution in irrigation water usually brings the pH to an acceptable range, but test if you're working with already-acidic water or soils below pH 6.0.

Can I mix MAP 12-61-0 with calcium nitrate in the same tank?

Not in concentrated form. Phosphate ions (from MAP) and calcium ions (from calcium nitrate) react to form calcium phosphate, an insoluble white precipitate that will clog injectors, emitters, and tank outlets. Always use separate stock tanks for phosphorus-containing fertilizers and calcium-containing fertilizers.

When applying through a single irrigation line, inject each from a separate tank so they only mix in the highly diluted irrigation stream, where precipitation is no longer a risk. This is standard practice in commercial fertigation programs.

What makes MAP 12-61-0 ideal for flowering and fruiting?

Phosphorus is the primary driver of reproductive growth in plants. It enables ATP production (the energy currency for all metabolic activity), supports cell division during rapid fruit development, and triggers the hormonal signaling that initiates flower bud formation. The 61% P₂O₅ concentration in MAP 12-61-0 is among the highest available in any water-soluble fertilizer, delivering maximum phosphorus per unit of product.

For best results, begin increasing MAP application rates 1–2 weeks before expected flowering to build phosphorus reserves in plant tissue before the bloom window opens.

Is MAP 12-61-0 safe to use in hydroponics?

Yes — MAP 12-61-0 is commonly used as a phosphorus source in hydroponic nutrient solutions at 0.5–1.0 grams per gallon. Because it is acidic, always measure and adjust pH after adding MAP to your reservoir. Maintain 150–200 ppm phosphorus in solution for most crops during vegetative and early flowering stages.

Important: add MAP to the reservoir before any calcium-containing nutrients to prevent localized precipitation during mixing. Always pre-dissolve MAP in water before adding to the main reservoir.

How does excess phosphorus affect micronutrient availability?

High phosphorus levels in solution or soil can suppress the uptake of zinc, iron, and manganese by competing for the same transport sites in roots. This is particularly relevant in high-P fertigation programs where EC and phosphorus levels are elevated for extended periods.

Monitor plants for signs of iron or zinc deficiency (interveinal chlorosis, small new leaves) during intensive MAP programs and supplement with Chelated Iron EDTA or Chelated Zinc EDTA as needed. Staying within recommended rates significantly reduces this risk.

GROW WITH CONFIDENCE
Product Quality Guaranteed
  • Technical-grade monoammonium phosphate manufactured to higher purity standards than agricultural-grade products
  • Registered with the California Department of Food and Agriculture (CDFA)
  • Independently lab tested for heavy metal content to ensure crop safety
  • Consistent batch-to-batch chemistry for reliable nutrient dosing
Hassle-Free Return Policy

We stand behind the quality of our MAP 12-61-0 Water-Soluble Fertilizer. If you're not completely satisfied with your purchase, we offer a 90-day money-back guarantee. Simply return the unused portion in its original packaging and we'll process a full refund, no questions asked.

Environmental Responsibility
  • Precise liquid delivery reduces phosphorus runoff compared to broadcast granular application
  • Technical-grade purity minimizes unnecessary chemical loading in soil and water
  • We source raw materials from reputable suppliers meeting current environmental standards
  • Ongoing research into efficient nutrient delivery to minimize environmental impact
Charitable Contributions

At Greenway Biotech, we believe in giving back to our community. 1% of all profits from our product sales go to the Greenway Foundation, dedicated to supporting children's education. Your purchase contributes directly to improving educational opportunities for children.

For more information, visit greenway.foundation.

DOCUMENTS
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  • Blog articles about MAP, phosphorus fertilization, and fertigation will be linked here once published.
HAVE QUESTIONS?

Check out our full FAQ page or contact our experts for personalized advice.

📧 questions@greenwaybiotech.com