Compost, whether you make it yourself or buy it, is very important for the health of your soil. Plants grow best in soil that is healthy. One question you might have is when is the best time to add compost to your yard.
- Should I add dirt right before I plant?
- Or should I wait for the compost to break down even more in the soil?
What is manure?
Human and animal waste, mostly bedding straw and animal feces, are the main types of manure used as fertilizer in farming and gardening. The types of organic fertilizer that are used most often are
- Animal waste
- Manure compost
- The green stuff
There are a lot of different kinds of manure, but most of them fall into three main groups. There are pros and cons to each type, but the main goal is to add nutrients to the land. Head over to our in-depth guide to manure to learn more about the different kinds.
There are some important things you should think about before you spread compost or manure in your yard. This guide will help you figure out what kind of compost or manure will work best for your plants and soil, as well as the best time and amount to use.
Adding animal manure to yard soil is a good idea. It gives plants nutrition in the form of nitrogen, phosphorus, and potassium, as well as vitamins. It also provides organic matter. Increasing the amount of organic matter in the soil makes the structure better, helps dry soils hold more water, helps clay soils drain better, gives nutrients that break down slowly, and encourages the growth of good soil organisms. The manures that are used as fertilizers usually come from animals that eat plants, like cows, sheep, chickens, and so on. (Never put pig, dog, or cat waste in your yard or compost pile.)
Plants can’t use all of the nitrogen in fertilizer at once because some of it may be locked up in organic forms. Microorganisms in the soil break down organic compounds over a number of years, turning the released nitrogen into NH4. Only then is it available to plants. The exact amount of this change depends on the animal it came from, the temperature, the amount of moisture in the air, and how it was handled. Usually, only 30% to 50% of the organic nitrogen is usable in the first year. After that, the amount slowly drops each year.
Manure as a Soil Builder and Nutrient Source
Along with organic matter, manures contain most or all of the 14 plant mineral nutrients that come from the soil. The rich, dark color of topsoil comes from organic matter, which is broken down plant and animal flesh. Adding manure or compost to the soil can improve its health and productivity by:
- Makes more nutrients available to plants and storing them in the soil;
- Makes more water available to plants and storing it in the soil;
- Improves the structure of the soil, which helps air flow and drainage;
- Supports the communities of microorganisms that live in the soil;
- Lowers the risk of compaction and surface crusting.
Benefits of Adding Compost To Your Garden
- Adding compost to your dirt will make it stronger. It holds particles together to make bigger groups, or “aggregates.” This makes the dirt soft and crumbly. Soils that are compact and made of clay become less solid, while sandy soils become better at holding on to water and nutrients.
- Adding compost to your soil makes it better at holding water. When you water plants this way, the water will stay on them longer than when you use irrigation, where it can drain away after being given. This seems to go against the last tip at first, but compost will help the soil drain better. Poor draining can mean either soil that is too wet or soil that drains too quickly. When the dirt is too wet, plant roots may find it hard to take hold. If it drains too quickly, plants might not be able to take in enough nutrients. By making the earth better at retaining water, letting air flow, and draining, compost helps keep these problems from happening.
- Adding compost to the soil makes it better able to hold on to nutrients that would normally be washed away in heavy rain, for example. Nitrogen is one of these nutrients, and it is very good for plant growth. As the compost breaks down in the soil, it makes room for a healthy community of microbes and plant life, like earthworms.
Adding about 5% more organic matter is good for many soils and crops. Adding manure and compost to the soil is a great way to increase the organic matter and keep the soil fertile so plants can grow well. A lot of manure that hasn’t been broken down yet or a lot of covering material that isn’t sand (straw, wood shavings, etc.) will break down slowly over time and add organic matter to the soil.
There is more organic matter in solid and semi-solid manures (<75% water content) and composts than in watery manures and slurries (>75% water content). This makes them better at building soil.
Also, manures are easy to compost because they have low ratios of carbon to nitrogen (C:N), which makes composting go quickly. This piece is mostly about solid manures and composts that are used in gardens, cities, and small farms.
When you shouldn’t use plant manure?
It is best to add manure to your garden or veggie patch three to four months before the plants are fully grown and ready to be picked, but there are times and situations when you shouldn’t.
- When the manure is new and hasn’t had time to break down
- When it’s very hot outside
- Whenever it rains or snows
- When plants and seeds are being grown,
- When pets can get to the area that is hurt,
When to Put Manure on Gardens
When applying manure, it’s best to wait 90 to 120 days before harvesting edible crops. This means that spring applications are not possible because most vegetables are ready to pick before that time.
Applying manure in the fall is one way to make sure there is enough time between when the manure was put down and when the crop is gathered. In general, you shouldn’t use manure on a garden that has already been sown.
Adding Compost In Autumn
If you add compost in the fall, it should be absorbed by the soil during these slower months. In fact, many gardeners stop growing veggies during this time of year. Many vegetable gardeners find they have more time to amend the soil in the fall than in the spring, when things get busy.
Your earth will be healthy and ready to go by spring. It may be helpful to add compost at this time of year if you’re not sure if it has fully processed.
The organic matter shouldn’t get in the way of the growth of newly planted veggies as long as it’s still breaking down. That being said, once the compost has fully broken down (which it will have done by spring), you can start planting and sowing right away to enjoy its benefits.
Before you put compost in the yard in the fall, make sure you get rid of any dead plants. Put down two to three inches of compost, and then use a leaf rake or another good garden tool to work it into the top few inches of soil. You can also add a cover crop or leaf mulch to the soil at this time.
Adding Compost In Spring
Some gardeners like to add compost to their beds in the spring, which is also a good idea. You will need to be a little more careful with your time, though. Most of the time, you should add the compost to the dirt about two weeks before you plant. This will make the dirt better and help new plants grow. Still, adding a handful of compost while you plant some veggies won’t hurt.
If you add compost to your garden in the spring, close to planting and sowing time, be aware that if the compost is only partially decomposed, it can actually lower the amount of nitrogen that young plants can use. This is because microbes in the soil will use the nitrogen for their own purposes as the organic matter breaks down. You can get around this by adding manure or something else to the dirt.
Putting on the sides and the top
When you side dress your garden, you put small amounts of soil around the bases of certain plants or along certain rows. You can do this in late spring or early summer. Gently work it into the dirt, being careful not to disturb the roots. Leave a room of one to two inches around the plant stem. If flowers have already started to bloom, side dressing should not be used because it can stop the process. Some people use fertilizer instead of soil for side dressing, too. If you want to give plants nutrients while they grow, fertilizer is your best bet. It can also be helpful to use both at the same time.
Spread a layer of compost or something else about 1 to 2 inches thick on top of the dirt in your garden to dress it up. When you top dress the soil, you can leave compost on top of it. Worms, beetles, other creatures, and so on can take care of it from there. Of course, you can work it into the top inch or so of dirt if you’d rather. Top dressing is often used for plants in pots and raised beds.
How Much Animal Manure Should I Really Use?
How much manure to use relies on the crops that will be planted, the amount of N, P, and K in the manure, and the results of a soil test that shows how fertile the soil is. The nutrients in manure vary by
- kind of animal,
- scheme for feeding,
- what kind of bedding was mixed in with the dung,
- aged dung and how long it was stored,
- about how much water is in the manure and whether it will be mixed into the soil right away (for example, tilled in or spread out on top of the ground).
Nutrient Availability
Exactly how much manure do you need?
If you bought composted manure in a bag, the sticker will tell you how much to use and how much nutrients it has. It might be harder to tell if the manure you’re putting in your garden is too much, too little, or just right if it comes from a friend’s farm in buckets, your backyard chicken coop, or a neighbor’s horse barn.
There are a lot of different things that affect how many nutrients are in farm soil. The nutrients in the dung will be available for plant growth based on how quickly the organic parts break down and are released. In general, 70–80% of the phosphorus and 80–90% of the potassium will be available from the waste in the first year. It’s harder to figure out nitrogen supply because microbes have to work to make it available for plants to take in.
| Manure type | Apply pounds per 100 square feet. | |
| Dairy cow | no bedding | 85 |
| with bedding | 90 | |
| composted | 210 | |
| Sheep | no bedding | 30 |
| with bedding | 45 | |
| Poultry | no litter | 25 |
| with bedding | 35 | |
| composted | 75 | |
| Horse | with bedding | 55 |
You can guess how much to use without having to weigh the materials because a 5-gallon bucket holds about 25 pounds of fresh dung or compost. Spread three buckets of cow manure that doesn’t have bedding over a 10×10-foot garden to add 0.2 pounds of nitrogen that can be used. For the same amount of nitrogen, you’d need to cover the same area with 8 buckets of cow dung that has been broken down.
Most of the time, how much manure is used depends on how much nitrogen it contains and how much is expected to be available for the first growth season. But keep in mind that some manure has a lot of phosphorus in it, so you might add way too much phosphorus while adding enough manure to meet the plant’s nitrogen needs. It is important to test your soil to see if it is building up too much phosphorus. If it is, you should probably use a different type of fertilizer with little or no phosphorus for a while. You should also do this to see if manure alone is meeting the plants’ other nutrient needs.
Using manure in the garden the right way can give your plants nutrients and help the dirt hold its shape. Too much manure can cause nitrate leaching, nutrient waste, too much plant growth, and salt damage in some manures. And putting fresh manure on land where food items are grown can make those areas contaminated with pathogens that cause disease.
How to Break Down Manure
By composting manure before spreading it in the yard, you can kill parasites and cut down on weed seeds. It’s also easier and safer to use soil that has been mixed with other things. To begin, make a pile that is about 3 to 5 feet high and wide. Even though this size pile is ideal, the compost pile needs to be at least 1 cubic yard in order to hit the suitable temperatures.
The carbon to nitrogen (C:N) ratio needs to be just right for the composting process to work well. The best C:N ratio is 25:1, but rates as low as 20:1 and as high as 40:1 will also work. You should also think about how much wetness is in the material. The best amount of wetness in manure is between 50 and 60%, but any amount between 40 and 65% is fine.
Most of the time, manure that has bedding mixed in will have a C:N ratio and a wetness level that are fine. If there isn’t much or any bedding in the pile and a lot of dung, add some dry carbon sources like straw, corn stover, or leaves to raise the C:N ratio and lower the moisture level to a safe level.
Once the manure is piled up, anaerobic organisms start to break down the organic matter using oxygen, water, carbon, and nitrogen to make heat and carbon dioxide. The pile should be turned often to add more air and keep it from getting too hot, which would kill the good microorganisms. Two or three times a month, turn your home compost pile with a shovel or yard fork. You should keep adding water to the garbage until it feels like a slightly wrung-out sponge. When you touch the garbage, you should always wear gloves and wash your hands afterward. If you take care of the pile correctly, it should get as hot as 130 to 140°F.
The composting process is almost over when the pile cools down to room temperature. Once manure is digested, it will lose about 30% of its volume. This usually takes 4 to 8 months for well-kept garbage piles. After that, the compost needs to be left to cure for another two to four months before it is ready to be used in the yard. For composting manure, it is best to use a two-bin method. One bin can be used to compost the manure, and the other bucket can be used to dry it out. When it’s done, the compost will be like hummus and feel like dirt. If you start a well-kept pile in early spring, it’s usually ready to spread by fall.
How to Understand Compost and Dung
Fresh dung
A lot of ammonium or soluble nitrogen is usually found in fresh dung. This means that there is more nitrogen available than in composted soil. Poultry manure has a lot of ammonia and can easily catch fire if it’s spread too much. Fresh dung has a lot of ammonia and nitrogen, so it needs to be mixed in 6 to 8 inches within 12 hours of being spread. A lot of the liquid nitrogen will be lost to the air as ammonia if it is not mixed in. If you mix the dung with bedding or litter, it will make it less nutritious. If there is a lot of straw or wood, the C/N ratio may go up, which could make nitrogen less available to plants. If there is more than 25 times as much carbon as nitrogen, the nitrogen will get stuck.
There are also a lot of salts in fresh manure, especially manure from chickens, turkeys, and other animals. Do not plant anything in the area for 3 to 4 weeks after salting it to protect it from damage.
There may be a lot of live weed seeds in fresh manure, which can cause a weed problem. Many people think that horse dung does this because horses don’t digest their food as well as some other animals do, and seeds go through their digestive system whole.
Fresh manure should never be used on fruits and veggies because it could spread diseases like E. coli to people. If the edible part of the plant is touching the earth, like carrots, beets, or potatoes, you should apply fresh manure at least four months before you harvest. Fresh dung should be spread on other crops that can be eaten at least three months before they are picked. Since the growing season is only about four months long, you should only use new manure in the fall. If you are planting food crops or will be planting them, you should not use it in the spring or during the growing season.
Composted manure
When you compost dung, you get rid of some of its problems, like the smell. Since it doesn’t have as much water in it, it’s lighter and easier to move. If the pile gets hot enough, the composting process may kill weed seeds and germs. But salts may be more concentrated, and some of the nitrogen is lost. This leaves behind the organic forms, which are more stable. It is less easy for plants to use nitrogen from composted manure, but it will add more organic matter to the soil than new manure.
But digested manure might not be enough to give fast-growing plants all the nutrients they need if it is not used in large amounts. Composted manure doesn’t need to be mixed into the soil right away like fresh manure does, but it should be mixed in to a depth of 6 to 8 inches whenever possible to get the most out of the compost. Spread in the spring? If so, wait at least one month before planting crops so that the increased microbial activity doesn’t stop seeds from sprouting.
If you have easy access to fresh manure, you can try composting it yourself. However, most people just buy bagged composted manure from garden shops and nurseries.
You can improve the health of your dirt and help plants grow by following these steps.