add organic matter for compost

Asked May 1, 2014, 9:51 PM EDT

The following is the recommendations I received from my MSU soil test. Is it possible that I could add organic matter high in nitrogen such as used coffee grounds to achieve my desired results. Your soil test indicates you need to apply 3 to 4 lb. Nitrogen (N)/1000 sq. feet, 0 lb. phosphate (P2O5)/1000 sq. feet and 0 lb. potassium (K20)/1000 sq. feet to meet recommendations. Below are examples of fertilizers that could be used. After you select a fertilizer, use the fertilizer calculator to determine how much phosphorus and potassium the fertilizer you selected will apply. Thanks, Michael L. Buza

Genesee County Michigan

3 Responses

I don't even know what your soil test was for. I also do not have the code so I cannot supply additional information.

But I can tell you that coffee grounds are not high in nitrogen and are not considered a fertilizer. Coffee grounds add organic matter and acidify the soil somewhat.

If you have a recommendation that indicates 3-4 lb. of nitrogen, that means an "actual fertilizer" that is 100% pure. None exist. They are all percentages. 46-0-0 is 46% nitrogen and no phosphorus or potassium. When you calculate how much the 3-4 lb. is, it comes out to 7-9 lb.

21-0-0 is 21% nitrogen with no phosphorus and no potassium. That means that at 3-4 lb., you would use 14-19 lb. of 21-0-0.

Because these are percentages and not 100%, the amount you use of each is different.

If you are adding organic matter, usually compost or composted manure is used. It also does not have any nutritive value, just value as organic matter. This is usually used in gardens and it is more difficult to apply to lawns.

When the recommendation indicates 3-4 pounds, this is for the entire season, divided into multiple applications, depending on the fertilizer.

If you are using organic nitrogen sources, the numbers will be completely different.

What type of organic fertilizer do you recommend. This is for my garden. Is all organic matter the same? Why do some organic magazine recommend adding certain types of organic material to add nutrients?

I would recommend one that has numbers close to what your soil needs. I do not have or have seen your soil test so I cannot be specific. I have no idea what organic fertilizers are available in Genesee County or if you will have to look at other locations to find them.

I am not sure what you are asking about organic matter. It is the same because it is from something that was formerly living. They are different in that it could be all the same material...like coffee grounds.. or it could be a mixture of dozens of kinds of materials. But it does not have numbers like fertilizers do.

As I stated before, organic material like compost is not fertilizer. The nutrients are there in tiny, tiny amounts. Even if you are talking about animal manure, there is probably well less than 1% nitrogen, phosphorus and potassium in it. Whereas, a nonorganic fertilizer like 12-12-12 has 12% of each.

If using organic material, they will all differ in what they contribute. You have to know what you need for the garden and which organic fertilizers will supply those nutrients, but compost is not fertilizer.