If a soil test reveals that your soil is lacking nitrogen, then you are probably looking for a way to supplement this important nutrient in your garden. Luckily, there are many options for high-nitrogen fertilizers.
So, what fertilizer is high in nitrogen? Fertilizers that are high in nitrogen include sodium nitrate, feather meal, blood meal, hoof and horn meal, hair, fish meal, crab meal, animal tankage, bat guano, soybean meal, cottonseed meal, fish emulsion, manure, and compost.
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.
What Fertilizer Is High In Nitrogen?
Here is a table with some of the best fertilizers with high nitrogen content. You can find more detail about each type of fertilizer after the table.
Note that N = Nitrogen, P = Phosphorus, and K = Potassium.
|9 to 14||1.5 to 2||0||NA|
|Fish Meal||10||4 to 6||0||Medium|
|Bat Guano||5.5 to 8||4 to 8.6||1.5||Medium|
|4 to 6||2.5 to 3||1.6||Slow to|
|Manure||0.5 to 6.5||0.2 to 4||0.4 to 3||Medium|
|Compost||1.5 to 3.5||0.5 to 1||1 to 2||Slow|
Sodium nitrate is a white solid that is water soluble, often used in fertilizers as a source of nitrate. It 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 has a fast release time, but should not be used for more than 20% of a crop’s nitrogen requirement.
Sodium nitrate does not contain any phosphorus or potassium.
For more information, check out this article on sodium nitrate from Wikipedia.
Feather meal is made from poultry feathers and 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 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.
Feather meal does not contain any phosphorus or potassium.
For more information, check out this article on feather meal from Wikipedia.
Blood meal is a powder made from the dried blood of animals (often cattle or hogs), and like bone meal, is often a by-product of slaughterhouses.
Blood meal contains 12.5% nitrogen, making it better than manure and compost in terms of percentage nitrogen by weight.
Blood meal has a medium release time, and is effective for 6 to 8 weeks.
Blood meal also contains 1.5% phosphorus and 0.6% potassium by weight.
For more information, check out this article on blood meal from Wikipedia.
Hoof and 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.
For more information, check out this article on hoof and horn meal from Feedipedia.
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 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, which you may not want to mix 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 months to a year.
Hair also contains 26% phosphorus by weight, although it does not contain any potassium.
Fish meal is a powder made from ground up fish parts, including bones. Fish meal is a good source of nitrogen, containing 10% nitrogen by weight.
Fish meal has a medium release time, and 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.
For more information, check out this article on fish meal from Wikipedia.
Crab meal is the ground up remains of crabs, 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 is another good fertilizer for your garden. It has a slow release time, and is effective for 4 to 6 months.
Crab meal contains small amounts of phosphorus (0.25%) and potassium (0.05%).
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.
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.
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 is effective for perhaps a month or two.
One caution is that bat guano has a low pH (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, or else 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!
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.
For more information, check out this article on guano from Wikipedia.
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.
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.
Soybean meal has a slow to medium release time.
For more information, check out this article on soybean meal from Wikipedia.
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 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 good all-around source of the big three nutrients.
For more information, check out this article on cottonseed meal from Wikipedia.
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 than most 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.
For more information, check out this article on fish emulsion from Wikipedia.
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 can be effective for 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!
For more information, check out my article on manure.
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 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 Soil?
Yes, you can have too much nitrogen in your soil. Too much nitrogen in soil can prevent a plant from absorbing other important nutrients from the soil.
High nitrogen levels in the soil can also cause plants to grow lots of lush leaves and foliage, but fewer flowers and fruit.
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.
By now, you have a much better idea of which fertilizers (both natural and man-made) have high 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.
I hope you found this article helpful – if so, please share it with someone else who can use the information. If you have any questions about fertilizers that are high in nitrogen, please leave a comment below.