What Fertilizer Is High In Nitrogen? (14 Natural Nitrogen Sources) – GreenUpside – Learn how to grow a green garden with us!

If a soil test reveals that your soil is lacking nitrogen, you find a way to get this important nutrient back into your soil, ASAP.

Nitrogen (N) is one of the Big Three nutrients that plants need to survive, along with phosphorus (P) and potassium (K). This NPK trio makes up the basis of most fertilizers, and a balanced blend of the three helps plants grow, flower, and fruit.

Plants use nitrogen for vegetative growth. Chlorophyll is made of nitrogen, and plants use it to photosynthesize sunlight into energy. So the more nitrogen in your fertilizer, the better, right? Not necessarily.

Compost is a great all-around soil amendment, but if your soil is lacking in nitrogen you might need a nitrogen-rich fertilizer.

Nitrogen triggers plant growth, but too much nitrogen can cause a plant to grow leggy stems and overly bushy foliage, limiting the ability of the plant to produce fruit. So, either use a balanced fertilizer blend or use a high-nitrogen fertilizer in the early stages of plant growth, and switch to a phosphorus and potassium-rich fertilizer to transition your garden to flowering and fruiting.

There are more than a few natural options for high-nitrogen fertilizers, including sodium nitrate, feather meal, blood meal, hoof & horn meal, hair, fish meal, crab meal, animal tankage, bat guano, soybean meal, cottonseed meal, fish emulsion, manure, & compost. Some of these fertilizers also contain phosphorus and potassium.

Of course, you can use a mixture of any of these sources of nitrogen, depending on what you have available.

Let’s get into more detail about just how much nitrogen each of these fertilizers contains, and how long it takes them to release into the soil.

(You can also watch my YouTube video on this topic if you prefer – the video is linked below.)

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What Fertilizer Is High In Nitrogen?

Reference the table below for a list of some of the best natural fertilizers with the highest nitrogen content.

Note the numbers given in the table are percentages by weight, and that N = Nitrogen, P = Phosphorus, and K = Potassium. (Learn more about NPK nutrients on fertilizer labels in my article here).

	% N	% P	% K	Speed
Sodium Nitrate	16	0	0	Fast
Feather Meal	15	0	0	Slow
Blood Meal	12.5	1.5	0.6	Med
Hoof & Horn Meal	9 to 14	1.5 to 2	0	NA
Hair	12	26	0	Very Slow
Fish Meal	10	4 to 6	0	Med
Crab Meal	10	0.25	0.05	Slow
Animal Tankage	7	10	0.5	Med
Bat Guano	5.5 to 8	4 to 8.6	1.5	Med To Fast
Soybean Meal	6.5	1.5	2.4	Slow to Med
Cotton Seed Meal	4 to 6	2.5 to 3	1.6	Slow to Med
Fish	5	1	1	Fast
Manure	0.5 to 6.5	0.2 to 4	0.4 to 3	Med to Fast
Compost	1.5 to 3.5	0.5 to 1	1 to 2	Slow

This table summarizes various fertilizer types and their nutrient content (nitrogen, phosphorus, and potassium). The numbers in the table are percentages of each nutrient by weight.

Sodium Nitrate

Sodium nitrate is commonly used as a food preservative but can also be used in the garden as a high-nitrogen fertilizer. Sodium nitrate occurs naturally in large deposits in Chile and Peru, among other places.

Sodium nitrate contains 16% nitrogen by weight, making it an excellent source of nitrogen for plants. It is water soluble and has a fast release time, but it should not be used for more than 20% of a crop’s nitrogen requirement.

However, sodium nitrate does not contain any phosphorus or potassium, so don’t use it in place of a balanced fertilizer. Instead, use sodium nitrate when you need to supplement only nitrogen for your soil.

You can find Chilean sodium nitrate fertilizer from Hoss Tools (it is OMRI listed for organic use, and you can buy a 10-pound bag or a 30-pound bag.

Feather Meal

Feather meal is made from poultry feathers and is a byproduct of processing birds for meat. The feathers are heated under pressure and ground down into a powder to form the meal.

Unlike sodium nitrate, feather meal is not water-soluble. It releases its nitrogen slowly and is only effective for 4 to 6 months.

Feather meal contains 15% nitrogen by weight, making it another excellent source of nitrogen for your soil. It should be added to a compost pile to aid in decomposition so that the nitrogen becomes available for plants.

If you keep chickens, you might end up with some feathers in the manure pile. This will add more nitrogen to the pile, so be sure to let it age first before applying it to the garden!

Feather meal does not contain any phosphorus or potassium. As a result, it works best as part of a mix made up of other fertilizers to provide balanced nutrition for plants.

You can buy feather meal from Fedco Seeds.

Blood Meal

Blood meal is a powder made from the dried blood of animals (often cattle or hogs). Like bone meal, it is often a by-product of slaughterhouses.

Blood meal contains 12.5% nitrogen by weight, and it is water soluble. It makes far better fertilizer than manure and compost in terms of percentage nitrogen by weight, plus blood meal has a medium release time so it’s effective for 6 to 8 weeks.

Blood meal also contains 1.5% phosphorus and 0.6% potassium by weight. This makes it a little more balanced as a fertilizer than some of the other ones earlier in this list.

Tractor Supply Company sells blood meal in four-pound bags.

Hoof & Horn Meal

Hoof and horn meal is made by grinding up the hoof and horn byproducts of processing cows and other animals. The hooves and horns are treated and ground into powder to produce the meal.

animal horn — Horn meal contains at least 9% nitrogen by weight, making it another excellent source of nitrogen for your soil.

Hoof and horn meal contains 9% to 14% nitrogen by weight, meaning it is a good source of nitrogen for your garden.

Hoof and horn meal also contain 1.5% to 2% phosphorus, although it does not contain any potassium. This makes it a good choice if you need to supplement nitrogen and phosphorus but not potassium.

Hair

Hair may not be the first thing you think of when you are looking for fertilizer for your garden. However, hair is 12% nitrogen by weight, meaning that it has more nitrogen than any manure or compost you can find.

Hair is a very slow-release fertilizer, and it is effective for 4 to 12 months. However, it is relatively easy to find, since it is a waste product of every barbershop.

The only problem is that hair from barbershops will often contain chemicals, such as hair spray or gel. As a result, you may not want to mix it into your garden soil.

Instead of applying hair directly into your soil, your best bet is to put it into a compost pile, along with some of the other nitrogen sources listed here. That way, it can break down over the course of several weeks or months.

Hair also contains 26% phosphorus by weight, although it does not contain any potassium. This makes hair an excellent supplement to provide both nitrogen and phosphorus to your garden.

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Fish Meal

Fish meal is a powder made from ground fish parts, including bones. Fish meal is a good source of nitrogen, since it contains 10% nitrogen by weight.

Fish meal has a medium release time, and it is effective for 4 to 6 months.

Dry fish meal also contains 4% to 6% phosphorus by weight, although it does not contain any potassium. This makes it a good choice for a fertilizer if you do not need any potassium added to your garden.

You can find a 50-pound bag of fish meal from Grow Organic (they recommend 5 to 10 pounds per 100 square feet, so the bag would cover 500 to 1000 square feet in total).

Crab Meal

Crab meal is the ground remains of crabs (or other crustaceans, such as shrimp), including their tough shells, which contain chitin. Chitin can help plants to defend themselves from diseases.

Crab meal contains 10% nitrogen by weight and has a slow release time, making it a great fertilizer. Once you apply crab meal, it is effective for 4 to 6 months.

Crab meal contains small amounts of phosphorus (0.25%) and potassium (0.05%).

You can find Crab Meal from Build A Soil.

Animal Tankage

Animal tankage is whatever is left of an animal carcass after removing the fat and gelatin. Animal tankage is often used as a fertilizer since it contains 7% nitrogen by weight.

Animal tankage has a medium release time and contains an impressive 10% phosphorus and 0.5% potassium by weight, making it a good choice if your soil needs higher amounts of nitrogen and phosphorus than manure or compost can provide.

Bat Guano

Guano is the excrement of seabirds and bats. As gross as it may sound, bat guano is a fairly good source of nitrogen, containing 5.5% to 8% nitrogen by weight. It has a medium release time and is effective for a month or so.

bat — Bat guano contains a good amount of nitrogen, in addition to some phosphorus and potassium, making it a good balanced fertilizer.

It is difficult to find bat guano on your own, so you will probably need to buy it from a store or online.

One caution is that bat guano has a low pH. Since it’s so acidic, always use bat guano with caution to avoid burning your plants with a sudden change in pH. Bat guano can be directly applied in soils with high pH, or mix it into your compost pile to dilute the acidity.

Here is a fun fact for you: bat guano that accumulates over many years can eventually provide a source of phosphorus-rich rock phosphate once the excrement hardens into layers of rock!

Bat guano also contains 4% to 8.6% phosphorus and 1.5% potassium by weight, making it a great all-around fertilizer that provides plenty of each nutrient.

You can find Bat Guano from Espoma.

Soybean Meal

A byproduct of one of the most common protein sources for people and animals, soybean meal makes an excellent nitrogen-rich fertilizer. Soybean meal is typically produced by first extracting soybean oil from the beans, but may also contain ground soybean husks.

Soybean meal has a slow to medium release time and contains about 6.5% nitrogen by weight, as well as 1.5% phosphorus and 2.4% potassium, making it a great balanced fertilizer for the garden.

One warning: according to the North Carolina State University Extension, soybean meal can inhibit the germination of small seeds. To prevent this, start small seeds indoors and transplant them outdoors later when using soybean meal as a fertilizer.

You can find soybean meal from Down To Earth.

Cottonseed Meal

Cottonseed meal is what remains after cottonseed oil is extracted from cotton seeds. With a nitrogen content of 4% to 6% by weight, cottonseed meal is better than most manure and compost in terms of nitrogen density.

Cottonseed meal has a slow to medium release time, and it is effective for 4 to 6 weeks. It contains 2.5% to 3% phosphorus by weight and 1.6% potassium by weight, making it a balanced fertilizer that is a good all-around source of the big three nutrients.

Since cottonseed oil is somewhat acidic, it’s good practice to mix it into compost instead of using it directly on plants.

You can find cottonseed meal from Espoma.

Fish Emulsion

Fish emulsion is produced from the remains of fish that have been processed for fish oil or fish meal.

Fish emulsion contains 5% nitrogen by weight, making it a better source of nitrogen than most types of manure and compost. Fish emulsion also contains small amounts of phosphorus and potassium–about 1% each by weight.

You can either spray the foliage with fish emulsion (for foliar feeding) or apply a diluted solution to the soil. Fish emulsion has a fast release time, and is effective for 2 weeks.

You can find fish emulsion from Tractor Supply Company.

Manure

There are many different types of manure, including cow, horse, pig, and chicken.

Manure differs in its nitrogen content by animal; cow and horse manure contain only 0.5% to 1.5% nitrogen by weight, pig manure contains 0.4% to 2%, and chicken manure contains 1.5% to 6%.

All of these manures have a medium release speed, and they can be effective for up to two years.

Manures also contain small amounts of phosphorus and potassium as well, making them good all-around fertilizers. Just make sure to decompose manure completely before using it on your garden, to avoid burning your plants!

You can find manure from Home Depot (or make your own if you keep chickens, cows, horses, or pigs!)

Compost

Compost is made from kitchen scraps and yard waste, such as banana peels, orange rinds, grass clippings, and raked leaves.

Compost contains 1.5% to 3.5% nitrogen and small amounts of phosphorus and potassium. It’s perhaps the most accessible soil amendment, and you really can’t overdo it with compost! Since compost takes months to break down, you’ll see even better results in your garden after a season or two.

The best part about compost is that you can make your own in your backyard!

Can You Have Too Much Nitrogen In Your Soil?

It is possible to have too much nitrogen in your soil. Too much nitrogen in soil can prevent a plant from absorbing other important nutrients.

High nitrogen levels in the soil can also cause plants to grow lots of lush leaves and foliage, but fewer flowers and fruit.

carrot greens — Too much nitrogen in the soil causes lush green growth but may prevent flowers and fruit from forming.

In addition, adding too much nitrogen to your soil can also be wasteful. According to Purdue University, plants can only use so much nitrogen, and adding too much can lead to runoff, which can harm the surrounding environment.

The moral of the story is this: always get a soil test before adding any supplements to your soil. Make sure you really do have a nitrogen deficiency before adding supplements!

A soil test will also tell you if your soil is too acidic (low pH) or too basic (high pH), which can help you to decide which supplement to use.

Peas and other nitrogen-fixing legumes are an easy way to add nitrogen back into the soil.

Now that you know which natural fertilizers have the highest nitrogen content by weight, you can make the best decision for which fertilizer to use in your garden based on what your soil needs and your target imeline.

Remember that high levels of nitrogen in water can cause algae growth on the water, on the surface of the soil, or in a greenhouse. And you can always restore nitrogen to the soil with this list of nitrogen-fixing plants, if you’d rather add nutrients to your garden soil naturally.

So your soil nitrogen levels are back in check, but what about those other essential garden nutrients? You might need to see this list of low phosphorus fertilizers or my article on fertilizers that are high in potassium.

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