Many homesteaders are choosing to use manure and other organic fertilizers over chemical ones, and it’s easy to see why. Manure is rich in quality nutrients and is a primary part of nutrient recycling in nature—land produces crops, the crops feed the livestock, and the livestock fertilizes the land. When done right, it’s the perfect cycle. But while manure is good for most crops, I was curious to see if they’re also good for fruit trees, such as my potted Meyer lemon tree. I did more research to find out.
Manure is one of the best fertilizers for fruit trees since it has a high NPK along with other trace nutrients. Compared to chemical fertilizers, manure contains organic carbon, which improves soil health dramatically. It’s also abundant, affordable, and renewable, making it a preferred fertilizer for fruit trees.
So, while manure is shown to be one of the best fertilizers (if not the best), how exactly does it benefit fruit trees, and what’s the best way to apply it?
How Manure Benefits Fruit Trees
Manure benefits fruit trees by providing high amounts of nitrogen, phosphorus, and potassium, which are the three main nutrients plants require. It also provides trace nutrients such as copper, zinc, and selenium. Manure is an important part of nutrient recycling in nature and is a valuable addition to fruit trees.
Most, if not all plants, require nitrogen, phosphorus, and potassium as their main nutrients (abbreviated as NPK). And while manure has plenty of these nutrients, it also has generous amounts of trace, or secondary nutrients including copper, zinc, and selenium.
To get a better idea of how manure benefits fruit trees, it can be helpful to compare them to chemical fertilizers.
Manure vs Chemical Fertilizers
This is a big topic, and a controversial one, so I’ll try my best to summarize it with the least amount of bias.
“Approximately 70-80% of nitrogen (N), 60-85% of phosphorus (P), and 80-90% of potassium (K) found in feeds is excreted in the manure. These nutrients can replace fertilizer needed for pasture or crop growth, eliminating the need to purchase fertilizers. Plants do not distinguish between sources of nutrients. However, compared to commercial fertilizer, manure contains organic carbon which is the key to maintaining soil health, including the characteristics of cation exchange capacity, soil tilth, and water holding capacity.”University of Massachusetts Amherst
Manure is generally a better fertilizer than chemical fertilizers since it’s the result of many plant nutrients being digested and compacted. On the other hand, chemical fertilizers are derived from fossil fuels, the same material used in plastics, and are not beneficial to the long-term health of plants.
Not only that, but manure has organic carbon, which is a vital resource for the nitrogen and life in the soil. This is often referred to as the carbon-nitrogen ratio, which should be around 30:1, or 30 parts carbon to each part nitrogen.
Carbon is an essential component of healthy plants as beneficial soil microbes, including a fungal layer called mycelium, feed off liquid carbon (provided by the trees roots) and in turn provide plants with food, water, and disease resistance.
Fungi perform important services related to water dynamics, nutrient cycling, and disease suppression. Along with bacteria, fungi are important as decomposers in the soil food web. They convert hard-to-digest organic material into forms that other organisms can use. Fungal hyphae physically bind soil particles together, creating stable aggregates that help increase water infiltration and soil water holding capacity.USDA
Among the benefits listed above, these fungi are an integral part of ecosystems since they help break down the tougher fibers from branches and fallen trees that bacteria can’t process.
Because of these fungi, the carbon and other nutrients from the fallen trees can be broken down and used by other soil life, which is then distributed to directly to plants. Without these fungi, fallen trees, branches, and leaves would sit and pile up, not rotting and we’d have a big problem on our hands.
The problem is, chemical fertilizers short-circuit this trade between the soil microbes and plant life. After all, if the plants get nutrients directly from the fertilizers, why do they need to give the microbes carbon from their roots? This, combined with other conventional practices, such as tilling, kills the beneficial microbes (turning soil into dirt) and increases the plants susceptibility to drought, disease, pests, among many other complications.
So, while chemical fertilizers may work in the short term, they often harm the long-term health of plants and the soil. This is the same for chemical pesticides, herbicides, and fungicides since they’re all derived from the same thing—fossil fuels.
If you’re interested to learn more on the subject of soil health, I highly recommend checking out Gabe Brown’s book, Dirt to Soil.
Okay, back to using manure for fruit trees.
Which Type of Manure Is Best for Fruit Trees?
The best manure for fruit trees is chicken or rabbit manure since they have a higher NPK compared to other manures such as cow, horse, and goat. However, just about any manure is good for fruit trees if they’re processed correctly. For example, chicken manure is hot and will need to be composted before applying.
|Livestock||Average NPK of Manure*||Hot or Cold Manure|
As you can see, chicken and rabbit manure generally have a higher NPK than other manures, so they’re the best bang for your buck.
While cow, horse, sheep, and other manures are good for fruit trees, they’ll need to be composted first since they’re “hot” manures. They also don’t have as high of a nutrient concentration as chicken or rabbit manure, so you’ll need to apply larger volumes.
Still, don’t let this sway you if you have easy access to these manures! They still make a great source of nutrients!
How to Manure Fruit Trees
If you’re using fresh manure for your fruit trees, you’ll likely need to compost it first since it’s considered “hot” or has enough nitrogen to chemically burn plants. Manure should be hot composted over 15 days or cold composted for one year. Once composted, apply the manure around the drip line of the fruit tree.
Goat and rabbit manure is cold manure and does not need to be composted before applying. In these cases, you can use them immediately. Still, avoid over-applying them as even these nutrients can become too concentrated in the soil. Most other livestock manure will need to be composted first.
In hot compost piles over 130ºF, wait 15 days for the manure to compost before applying it to fruit trees. For cold composting, this process can take about one year.
Once composted, apply the manure around the drip line of your fruit tree. This is the area containing the feeder roots—which are the finer roots that can intake the most nutrients.
Also, avoid touching the manure to the trunk of your fruit tree, as this can introduce mold and disease. Keep the manure at least 3 inches away from the trunk and prune any lower branches that are close to the soil.
If you don’t want to wait for hot manure to compost, you can either use cold manure or buy manure that’s already composted and apply it directly to your fruit tree’s soil. For my fruit trees, I personally like using Espoma’s Organic Chicken Manure (found on Amazon).
If you’re interested in learning more about cold manures, here’s one of my favorite videos on the subject (by Growing Better Together).
How Much Manure Does a Fruit Tree Need?
If you’re fertilizing your fruit trees with manure once a year, it’s best to apply 5-10 lbs of composted manure around the tree’s drip line, or canopy. For more frequent applications of manure, apply 1-2 inches every 2 months around the drip line.
While some homemade fertilizers made from kitchen scraps can be used every 1-2 months, manure is much more nutrient-dense and takes longer to break down. For these reasons, manure is best applied less often, and in 5-10 lb amounts.
However, if you’d like to provide manure more frequently, you can use 1-2 inches of composted or cold manure around the drip line every 2 months.
If you notice your fruit tree having a reaction to the manure, such as yellowing leaves or leaf loss, then pause the fertilizer and check its sun, water, and soil levels if possible.
When to Manure Fruit Trees
Manure is best applied to fruit trees annually, in the early spring—after the last frost. This will provide the tree with the nutrients it needs for the growing season. On the other hand, manuring in the winter can chemically burn the roots as most trees are dormant, and don’t require many nutrients.
Like most other products, the nutrients in manure are absorbed into the soil and degrades over time. This means the most potent year is the first, with a steep drop off following each year after.
|Manure Type||Nutrient Availability in Year 1||Nutrient Availability in Year 2|
After the first two years, the manure’s nutrient availability in the soil will amount to about 5% in year 3 and 2% in each following year. For this reason, it’s recommended to fertilize your fruit trees once a year (in the early spring).
If you’d like to learn more about using manure for fruit trees, check out this video by Self Sufficient Me reviewing using cow manure for lemon trees.