If a soil test reveals that your soil is lacking nitrogen, you are probably looking for a way to supplement this important nutrient in your garden. Luckily, there are many natural options for high-nitrogen fertilizers.
So, what fertilizer is high in nitrogen? Natural fertilizers that are high in nitrogen include: 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 also below.)
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What Fertilizer Is High In Nitrogen?
Here is a table with some of the best natural fertilizers with the highest nitrogen content. You can find more detail about each type of fertilizer after the table.
Note the numbers given in the table are percentages by weight, and that N = Nitrogen, P = Phosphorus, and K = Potassium. (You can 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 |
their nutrient content (nitrogen, phosphorus, and
potassium). The numbers in the table are
percentages of each nutrient by weight.
For more information, check out this article on NPK values of fertilizers from the Oregon State University Extension.
Sodium Nitrate
Sodium nitrate is a white solid that is water soluble. It is often used in fertilizers as a source of nitrate.
Sodium nitrate occurs naturally in large deposits in Chile and Peru, among other places.
wikimedia.org/wiki/File:
Chilisalpeter_(Sodium_
nitrate).jpg
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.
Sodium nitrate does not contain any phosphorus or potassium. As a result, it is not a good choice for a balanced fertilizer.
Instead, use sodium nitrate when you need to supplement only nitrogen for your plants (a soil test will tell you this).
For more information, check out this article on sodium nitrate from Wikipedia.
Feather Meal
Feather meal is made from poultry feathers. It is a byproduct of processing the animals.
The feathers are heated under pressure and ground down into a powder to form the meal.
Feather meal is not water soluble, and it releases its nitrogen slowly. It is 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 find feather meal from Fedco Seeds.
For more information, check out this article on feather meal from Wikipedia.
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 a far better fertilizer than manure and compost in terms of percentage nitrogen by weight.
Blood meal has a medium release time, and it is 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.
You can find blood meal from Tractor Supply Company.
For more information, check out this article on blood meal from Wikipedia.
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.
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 contains 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.
For more information, check out this article on hoof and horn meal from Feedipedia.
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 up 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).
For more information, check out this article on fish meal from Wikipedia.
Crab Meal
Crab meal is the ground up 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.
For more information, check out this article on chitin from Wikipedia.
Crab meal contains 10% nitrogen by weight, and so it is another good fertilizer for your garden. It has a slow release time, and 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 also 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.
Animal tankage has a medium release time.
Bat Guano
Guano is the excrement of seabirds and bats. Bat guano is a fairly good source of nitrogen, containing 5.5% to 8% nitrogen by weight.
Image from: https://commons.
wikimedia.org/wiki/File:
Fulvous_leaf_nosed_bat.jpg
It is difficult to find bat guano on your own, so you will probably need to buy it from a store or online.
Bat guano has a medium release time, and it is effective for perhaps a month or two.
One caution is that bat guano has a low pH (that is, it is very acidic). So it should be used with caution to avoid burning your plants with a sudden change in pH.
Only use bat guano directly in soils with high pH. Otherwise, you will need to 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 rock phosphate once the excrement hardens into layers of rock!
(Rock phosphate is often used in fertilizers to provide phosphorus for plants).
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.
For more information, check out this article on guano from Wikipedia.
Soybean Meal
Soybean meal is used as a protein and energy source for people and animals. Often, soybean meal is produced by first extracting soybean oil from the beans. Soybean meal may also contain ground soybean husks.
Image courtesey of:
United Soybean Board
from: https://commons.
wikimedia.org/wiki/File:Soybean_Meal_
(10059014026).jpg
Soybean meal can also be used as fertilizer, since it contains 6.5% nitrogen by weight.
Soybean meal also contains 1.5% phosphorus and 2.4% potassium by weight. This makes it a good balanced fertilizer for the garden.
Soybean meal has a slow to medium release time.
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 outdoors later when using soybean meal as a fertilizer.
You can find soybean meal from Down To Earth.
For more information, check out this article on soybean meal from Wikipedia.
Cottonseed Meal
Cottonseed meal is what remains after cottonseed oil is extracted from cotton seeds. Cottonseed meal has 4% to 6% nitrogen, making it better than most manure and compost in terms of nitrogen content by weight.
Cottonseed meal has a slow to medium release time, and it is effective for 4 to 6 weeks.
Remember that cottonseed oil is somewhat acidic, so it may be a good idea to mix it into compost instead of using it directly on plants.
Cottonseed oil also 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.
You can find cottonseed meal from Espoma.
For more information, check out this article on cottonseed meal from Wikipedia.
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 1% phosphorus and 1% potassium by weight.
It has a fast release time, and is effective for 2 weeks. You can either spray the foliage with fish emulsion (for foliar feeding) or apply a diluted solution to the soil.
You can find fish emulsion from Tractor Supply Company.
For more information, check out this article on fish emulsion from Wikipedia.
Manure
There are many different types of manure, including cow, horse, pig, and chicken.
Cow and horse manure often contains only 0.5% to 1.5% nitrogen by weight.
Pig manure contains 0.4% to 2% nitrogen by weight.
Chicken manure contains 1.5% to 6% nitrogen by weight.
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!)
For more information, check out my article on manure.
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. It is a slow release fertilizer, and it also contains phosphorus and potassium.
The best part about compost is that you can make your own in your backyard. For more information, check out my article on how to make compost.
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.
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.
For more information, check out my article on how to do a soil test.
Conclusion
Now you know which natural fertilizers have the highest nitrogen content by weight. You also know how to choose which one to use, based on the time it takes for the fertilizers to release nutrients.
Remember that high levels of nitrogen in water can cause algae growth on the water, on the surface of soil, or in a greenhouse.
You can restore nitrogen to the soil with this list of nitrogen fixing plants.
If you want some ideas for how to add nutrients to your garden soil naturally, check out my article here.
You might also be interested to read my article on low phosphorus fertilizers or my article on fertilizers that are high in potassium.
I hope you found this article helpful – if so, please share it with someone else who can use the information.
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~Jonathon