Monoammonium Phosphate Fertilizer 11-52-0
- Regular Price
- $ 21.99
- Sale Price
- $ 21.99
- Regular Price
- $ 21.99
- Unit Price
- per
Monoammonium Phosphate (MAP) 11-52-0 Granular Fertilizer
Boost flowering, root development, and fruit set with our professional-grade granular MAP 11-52-0 — delivering 52% phosphorus for season-long soil nutrition.
Ideal Applications
FEATURES
🌸 52% Phosphorus Concentration
Provides one of the highest phosphorus densities available in granular form — delivering more P per pound than bone meal, TSP, or DAP for bloom and fruit support.
🌱 Ammoniacal Nitrogen (11%)
Nitrogen in ammonium form improves phosphorus uptake efficiency by acidifying the root zone, making P more available before nitrification occurs.
📦 Granular Controlled Release
Uniform granules dissolve gradually with soil moisture, providing season-long phosphorus availability rather than the immediate flush of water-soluble grades.
⚗️ pH Acidifying Effect
Ammoniacal nitrogen lowers pH around the root zone, particularly beneficial in alkaline soils where high pH locks out phosphorus and micronutrients.
🌾 Versatile Soil Application
Suitable for broadcasting, side dressing, banding, and pre-plant incorporation — compatible with spreader equipment for large-scale field applications.
🍓 Broad Crop Compatibility
Effective across vegetables, fruit trees, ornamentals, lawns, and commercial field crops including corn, soybeans, cotton, and small grains.
💰 Economical per Unit of Phosphorus
Lower cost per pound of P₂O₅ than water-soluble MAP for large-area soil applications — especially for broadcasting over gardens, orchards, and fields.
🔬 Tested for Heavy Metals
Independently lab tested for heavy metal content so you can apply with confidence in food gardens and commercial growing operations.
✅ CDFA Registered
Registered with the California Department of Food and Agriculture (CDFA) and meets all state labeling and nutrient analysis requirements.
🏭 Professional Grade
The same quality specification used by commercial growers and agricultural operations — available in sizes suited to home gardens and large-scale farms alike.
DERIVED FROM
MAP 11-52-0 granular is produced by reacting anhydrous ammonia with phosphoric acid, then granulating the resulting monoammonium phosphate salt into uniform particles. This granulation process distinguishes it from the water-soluble powder grade and is designed exclusively for direct soil application.
Primary Source
Monoammonium Phosphate (NH₄H₂PO₄)
Agricultural-grade granular MAP — the source of both the 11% ammoniacal nitrogen and 52% P₂O₅. Granulation creates uniform particles for mechanical spreading and controlled release.
SCIENCE BEHIND THE FORMULA
11-52-0: High-Phosphorus Granular Formula
MAP 11-52-0 is formulated to deliver maximum phosphorus to the soil with a supporting dose of ammoniacal nitrogen. The ratio is designed specifically for root development, bloom initiation, and fruit set — the plant functions most dependent on phosphorus.
🌿 Nitrogen — 11% (Ammoniacal)
Ammonium nitrogen (NH₄⁺) is held on soil cation exchange sites, resisting leaching while acidifying the rhizosphere to enhance phosphorus solubility. It supports vegetative growth without over-pushing leaf production at the expense of flowering.
🌸 Phosphorus — 52% (P₂O₅)
Phosphorus is essential for ATP energy transfer, root elongation, cell division, and reproductive development. At 52% P₂O₅, MAP delivers a concentrated phosphorus source that drives bloom production, fruit set, and root branching.
⭐ Potassium — 0%
MAP contains no potassium by design, allowing precise nutrient control when potassium levels are already adequate or when phosphorus-only supplementation is needed. Pair with Potassium Sulfate 0-0-53 for complete macronutrient coverage.
Why Granular MAP Performs Differently Than Water-Soluble MAP
⏱️ Season-Long Release
Granular MAP dissolves slowly with soil moisture over weeks and months, feeding roots continuously rather than delivering a single nutrient spike. This reduces leaching risk and extends the feeding window.
🌱 Root Zone Acidification
As ammonium nitrifies in the soil, it releases hydrogen ions that locally lower pH. This improves phosphorus availability and micronutrient solubility in the root zone, especially important in alkaline soils above pH 7.5.
⚙️ Mechanical Application Ready
Uniform granule size allows consistent distribution through rotary broadcast spreaders and drop spreaders — reducing application variability common with powdered fertilizers.
What to Expect After Application
Results vary with soil temperature, moisture, soil pH, and existing phosphorus levels. A soil test before application is recommended for best outcomes.
APPLICATION RATES & DIRECTIONS
MAP 11-52-0 is designed exclusively for soil application. Always incorporate into soil or water in thoroughly after application.
Side Dressing Application
| Crop Type | Rate per 100 sq ft | Application Method |
|---|---|---|
| Vegetables (General) | 2–4 lbs | 4–6" from plant stem |
| Tomatoes / Peppers | 3–5 lbs | At first flowering |
| Fruit Trees | 5–8 lbs | Drip line application |
| Flowering Plants | 2–3 lbs | Before bud formation |
| Root Vegetables | 4–6 lbs | At planting |
| Heavy Feeders | 6–10 lbs | Split applications |
Broadcasting Rates
| Application | Rate | Coverage |
|---|---|---|
| New Garden Beds | 5–10 lbs/100 sq ft | Till into top 6" |
| Established Lawns | 2–4 lbs/100 sq ft | Water in thoroughly |
| Pre-Plant Field | 200–400 lbs/acre | Incorporate before planting |
| Orchard Floor | 3–5 lbs/tree | Spread under canopy |
Coverage Guide by Package Size
| Bag Size | At 3 lbs/100 sq ft | At 5 lbs/100 sq ft | At 300 lbs/acre |
|---|---|---|---|
| 5 lb | ~167 sq ft | ~100 sq ft | — |
| 25 lb | ~833 sq ft | ~500 sq ft | — |
| 50 lb | ~1,667 sq ft | ~1,000 sq ft | ~0.17 acre |
HOW TO USE
Side Dressing Established Plants
- Create a shallow furrow 4–6 inches from plant stems, following the drip line.
- Distribute granules evenly at the recommended rate for your crop type.
- Cover granules lightly with soil to prevent runoff.
- Water thoroughly immediately after application to begin dissolving granules into the root zone.
Broadcasting & Soil Incorporation
- Apply granules evenly using a broadcast or drop spreader when soil surface is dry.
- For new beds, till or rake into the top 4–6 inches of soil before planting.
- For established lawns, water immediately and thoroughly after application.
- Avoid applying before heavy rain to reduce runoff risk.
Trees & Shrubs
- Spread granules in a circle at the drip line (canopy edge), keeping 6 inches away from the trunk.
- Lightly scratch granules into the soil surface with a rake.
- Water deeply after application to move phosphorus into the root zone.
- For young trees, split annual applications into 2–3 smaller doses.
Pro Tip: Apply at Flowering for Maximum Fruit Set
For tomatoes, peppers, and squash, side dress with 3–4 lbs per 100 sq ft when first flowers appear. This timing delivers phosphorus exactly when the plant needs energy for pollination, fruit cell division, and early fruit development — many growers notice more consistent fruit set and reduced flower drop when phosphorus is readily available at this stage.
When MAP 11-52-0 Is the Right Choice
- Broadcasting or side dressing over large areas like orchards, fields, or established gardens
- Soil preparation before planting where a slow-release phosphorus charge is beneficial
- Alkaline soils (pH 7.5+) where the acidifying effect helps improve nutrient availability
- Commercial-scale applications where cost-per-unit-of-phosphorus matters
When to Consider Other Options
- Fertigation or drip systems — use MAP 12-61-0 (Water Soluble) instead, which dissolves completely
- Foliar phosphorus feeding — granular MAP cannot be dissolved or sprayed; choose MAP 12-61-0 or MKP 0-52-34
- Organic-certified growing programs — consider Bone Meal 3-15-0 or Fish Bone Meal 4-17-0 as natural phosphorus alternatives
- Hydroponic systems — granular fertilizers are not suitable; use only fully water-soluble grades
MAP 11-52-0 CALCULATOR
PHOSPHORUS FERTILIZER COMPARISON
See how MAP 11-52-0 compares to other common phosphorus sources for soil application.
| Feature | MAP 11-52-0 (This Product) | MAP 12-61-0 | Triple Super Phosphate 0-46-0 | Bone Meal 3-15-0 |
|---|---|---|---|---|
| Phosphorus (P₂O₅) | 52% | 61% | 46% | 15% |
| Nitrogen | 11% ammoniacal | 12% ammoniacal | 0% | 3% organic |
| Solubility | Granular — NOT water-soluble | 100% water-soluble powder | Granular — slow release | Granular — very slow release |
| Application Method | Soil only (broadcast, side dress) | Fertigation, foliar, hydroponics | Soil only (broadcast) | Soil only (incorporation) |
| Release Speed | Controlled / season-long | Immediate | Moderate | Very slow (months) |
| pH Effect | Acidifying ↓ | Acidifying ↓ | Neutral | Slightly alkaline ↑ |
| Best For | Large gardens, field crops, orchards | Hydroponics, fertigation, foliar | Phosphorus-only applications | Organic gardens, slow-release P |
| Cost Efficiency | ★★★★★ Excellent for large areas | ★★★ Higher per unit | ★★★★ Good value | ★★ Expensive per unit P |
SAFETY & HANDLING
Personal Protective Equipment (PPE)
- Wear chemical-resistant gloves when handling granules
- Wear safety glasses or goggles to protect against dust
- Use a dust mask or N95 respirator in dusty application conditions
- Wash hands thoroughly with soap and water after handling
Storage Guidelines
- Store in a cool, dry place in the original sealed container
- MAP is hygroscopic — reseal tightly after each use to prevent clumping
- Keep away from direct sunlight and heat sources
- Store away from children and pets
- Do not store near incompatible materials such as strong acids or bases
Application Precautions
- This product is NOT water-soluble — do not attempt to dissolve or use in fertigation systems
- Keep granules away from direct contact with plant stems and foliage to prevent burn
- Apply before irrigation or rain for best results — avoid applying before heavy rain
- Do not apply to waterlogged or frozen soils
- Follow all local regulations for 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 thoroughly with soap and water
- Ingestion: Do not induce vomiting. Contact Poison Control (1-800-222-1222) or seek medical attention immediately
- 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
MAP 11-52-0 delivers phosphorus and a small dose of nitrogen. Complete your fertilizer program with these complementary products for balanced nutrition:
Potassium Sulfate 0-0-53
MAP has 0% potassium — add K for fruit quality, disease resistance, and overall plant vigor. Sulfate form avoids chloride buildup.
EssentialCalcium Nitrate 15.5-0-0
Additional nitrogen plus calcium for cell wall strength and blossom end rot prevention. Provides nitrate-N to balance MAP's ammonium-N.
RecommendedEpsom Salt (Magnesium Sulfate)
Magnesium for chlorophyll production and improved phosphorus uptake efficiency. Especially valuable in sandy or phosphorus-fixing soils.
AlternativeMAP 12-61-0 (Water Soluble)
Need fertigation or foliar phosphorus? Use the water-soluble grade instead — 61% P₂O₅ and fully dissolvable for liquid feeding systems.
OptionalChelated Iron EDTA 13%
Prevent iron chlorosis — especially important in alkaline soils being corrected with MAP. EDTA chelation keeps iron plant-available across a wide pH range.
OrganicBone Meal 3-15-0
Organic phosphorus alternative with calcium — great companion for mixed conventional/organic programs where you want slower P release with calcium benefit.
FREQUENTLY ASKED QUESTIONS
What's the difference between MAP 11-52-0 granular and MAP 12-61-0 water soluble?
MAP 11-52-0 (this product) is a granular form designed for direct soil application. It provides controlled, season-long phosphorus release through gradual dissolution and is ideal for broadcasting, side dressing, and pre-plant incorporation. It is NOT water-soluble and cannot be used in fertigation or foliar systems.
MAP 12-61-0 is a 100% water-soluble powder with 61% phosphorus, designed for fertigation, foliar feeding, and hydroponic systems where immediate phosphorus availability is needed.
Choose 11-52-0 for economical soil application with controlled release. Choose 12-61-0 when you need liquid-soluble phosphorus for drip, foliar, or hydroponic feeding. For a deeper comparison, see our guide on choosing the best phosphorus fertilizer.
Can MAP 11-52-0 be dissolved in water for liquid feeding?
No. This granular formulation is NOT water-soluble and should not be dissolved. Attempting to dissolve granular MAP will leave undissolved material that can clog irrigation systems. If you need a water-soluble phosphorus source for fertigation, foliar spraying, or hydroponics, use our MAP 12-61-0 (Water Soluble) instead.
When is the best time to apply MAP 11-52-0?
Vegetables: Work into soil before planting, then side dress when plants begin flowering. For root crops, apply all at planting.
Fruit trees: Apply in early spring before bud break, and optionally post-harvest to restore nutrient reserves. Split large applications into 3–4 smaller ones for young trees.
Ornamentals: Spring bloomers benefit from fall application; summer bloomers from early spring application.
Lawns: Cool-season grasses in early fall, warm-season grasses in late spring. For new lawns, incorporate into soil before seeding.
Will MAP 11-52-0 lower my soil pH?
Yes, over time. The ammoniacal nitrogen in MAP has an acidifying effect on soil as it nitrifies. This is beneficial in alkaline soils (pH 7.5+) where high pH locks out phosphorus and micronutrients. In already acidic soils (below pH 6.0), monitor pH over time and consider periodic liming if needed. A soil test before application is always recommended for best results.
Why doesn't MAP 11-52-0 contain calcium — and does that matter?
MAP does not contain calcium, and it's important not to mix it directly with calcium fertilizers like calcium nitrate in the same application. Calcium and phosphate react when in direct contact in concentrated form, forming insoluble calcium phosphate that reduces nutrient availability. Apply them separately, or allow irrigation water to move them through the soil independently. For crops with high calcium demand, such as tomatoes and peppers, apply calcium nitrate separately as a side dress or foliar treatment. Learn more about phosphorus nutrition in our article on the function of phosphorus in plants.
How much area does one bag cover?
Coverage depends on application rate. A 50 lb bag at 5 lbs/100 sq ft covers approximately 1,000 square feet. At a lighter rate of 3 lbs/100 sq ft, the same bag covers about 1,667 square feet. Use the MAP 11-52-0 Calculator above for precise amounts based on your specific garden size and crop type.
Which crops benefit most from MAP 11-52-0?
Crops with high phosphorus demands see the greatest benefit: flowering annuals (petunias, marigolds, zinnias), bulbs (tulips, daffodils), roses, fruiting vegetables (tomatoes, peppers, squash, melons), root vegetables (potatoes, carrots, beets, onions), and commercial crops (corn, soybeans, cotton, tree fruits). For more information, see our article on fertilizers that improve fruit yield.
Note: Phosphorus-sensitive plants like proteas and grevilleas should receive reduced rates or phosphorus-free alternatives.
GROW WITH CONFIDENCE
Product Quality Guaranteed
- Manufactured and repackaged in California, USA at our Madera facility
- Independently lab tested for heavy metal content for safe use in food gardens
- Registered with the California Department of Food and Agriculture (CDFA)
- Nutrient analysis guaranteed on label per CDFA requirements
90-Day Hassle-Free Returns
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 granular formulation reduces over-application and nutrient runoff risk
- Support for responsible nutrient stewardship and integrated crop management
- Transitioning to compostable packaging solutions
Charitable Contributions
1% of all profits go to our foundation, focused on improving educational opportunities for children.
DOCUMENTS
DISCOVER MORE
- What's the Function of Phosphorus in Plants? — Why P₂O₅ is critical for roots, blooms, and energy transfer
- What is the Best Phosphorus Fertilizer? — Compare MAP, bone meal, MKP, and TSP for different growing needs
- What Fertilizers Improve Fruit Yield? — How phosphorus-rich fertilizers like MAP boost fruit production
HAVE QUESTIONS?
Check out our full FAQ page or contact our experts for personalized advice.