How Much Compost Do I Need

How Much Compost Do I Need

Tired Of Asking ‘how Much Compost Do I Need For My Soil?’ Here’s A Guide To Solve All Your Problems.

People who do commercial farming, or those who grow plants in their small house gardens, take great interest in knowing more about composts. Compost helps in enriching the soil’s nutrient composition. It helps obtain better yields of vegetables and fruits, and accelerates the growth of flowers, crops, etc. To obtain these remarkable gains, people start adding a lot of compost for faster results.

While adding compost does help, the calculation for using compost should be appropriate to reap such benefits. You may have questions like ‘how much compost do I need’ or ‘what amount of compost is excess?’. This article aims to answer all your doubts and guide you about the use of compost.

Benefits Of Compost

Using compost provides several benefits, which we shall discuss further. However, neither does excessive use of compost guarantee these benefits, nor is it very healthy for the soil.

Using compost provides three major benefits to the soil. These benefits are :

1. Increases Fertility

All organic materials have high amounts of nutrients that are present in the form of complex compounds. During composting, bacteria and fungi break down these complex compounds to release nutrients. Nutrients such as nitrogen, phosphorus, potassium, etc. are present inside the compost in their simplest form. In this form, nutrients are best absorbed by the plants to help in promoting growth and development. Therefore, using compost while farming helps in increasing the soil’s fertility.

2. Improves Soil Structure

Compost helps in improving the structure of the soil by adding a layer of organic matter. This layer helps in preventing excess percolation through the soil and improving moisture retention. However, it does not make the soil too tight either, thus allowing it to remain aerated.

3. Improves Soil Health

Manure and other organic materials are converted into compost by the action of several beneficial bacteria and fungi. When these bacteria and fungi enter the soil, they help in killing harmful microorganisms. They also fixate nutrients for easy absorption by the roots, thus improving the soil’s overall health.

Amount Of Compost Required For Different Benefits

You might be wondering that if compost provides so many benefits to the soil, why shouldn’t you add loads of it at once? The problem with adding compost in excess is that different quantities of compost help in obtaining various benefits.

Moreover, the soil that you use might have certain nutrients already or might be completely non-fertile. It is also possible that the pH of your soil is not suitable for too much compost. All these factors must be taken into account before you calculate the amount of compost you can add. Adding unnecessary amounts of compost can lead to problems like nutrient toxicity, which ultimately leads to plant diseases.

1. Deciding The Amount For Increasing Fertility

When you only want to increase your soil’s fertility, using composts that have been in worm composters for more than three months, will not be a good option. It is because, during the curing phase, the growth of microbes is exponential. However, the nutrient content only increases by 3-5 percent of dry weight. Thus, in this case, compost will only act as a weak fertilizer, because your need for increasing soil fertility is higher.

So, we advise you not to waste too much compost here. Instead, it’s better to use a combination of compost and off-the-shelf organic fertilizers to enrich the soil with particular nutrients.

2. Deciding The Amount For Improving Soil Structure

As stated before, compost helps in improving soil structure by adding organic matter to it. Therefore, at times, you need to over-apply compost for this purpose. More the amount of compost, more the addition of organic matter.

However, before you add any compost to the soil, we recommend that you properly assess its texture. It is easier to enhance the soil structure of sandy soil by over-addition of compost as the properties like moisture retention are extremely low in such soils. However, with clayey or loamy soil, you need to be a bit careful.

3. Deciding The Amount For Soil Health

Just like our gut, enriching the biome composition of the soil helps in keeping it healthy. However, if you use excess compost that is not cured properly and has not had enough multiplication of microbes, you are just wasting it, as it will not be beneficial. You must either wait for composting to happen properly or use pesticides and other supplements to enrich soil health.

Buying Compost

Compost sells at most places as per imperial units of cubic yards. Therefore, you must know how much is a yard of compost before you go out to buy it.

The first step in calculating the amount of compost needed is to measure the area under plantation in square inches. After this, multiply the area with the depth till which you need to apply compost. It will give you the volume of compost you shall need in cubic inches.

Now convert the value into cubic yards. One cubic yard of manure accounts for 46,646 cubic inches. Simply divide the value you got in the first step by 46,646, and you shall know the amount of compost you need to buy.

Generally, for a 10 X 10 square foot field, you need to put compost till at least 2 inches deep. That accounts for a volume of 29,000 cubic inches. When you divide this value by 46,646, you get around 0.60. It means that you need to use compost just under 3/4ths of a cubic yard for your garden.


Whether you practice farming on a commercial level or do it for fun in your backyard, you will require compost to obtain better results. However, you cannot keep adding compost to the soil arbitrarily. If you have questions like ‘how much compost do I need’ or ‘how to buy enough compost from the market,’ you can follow the method explained above to get an idea. While you do not need to be accurate with your calculations, paying attention to the little details is always helpful.