Organic fertilizers come from materials that were at one time living or are byproducts of living things. Old leaves, peanut hulls, bone meal and animal manures are just a few examples of organic fertilizer sources. Like the inorganic sources, there are numerous sources of organic fertilizer materials. The goal of this document is to provide you with a few tips on how to use them properly.

There are advantages and disadvantages to using organic fertilizers. One advantage of organic materials is that they provide beneficial organic matter that can improve the soils water and nutrient holding capacity. This organic matter also creates an environment that encourages beneficial soil organisms such as earthworms. Another advantage is that organic materials take longer to breakdown and release nutrients. This creates a slow-release situation that provides nutrients over a longer period of time and can also help in reducing the loss of nutrients to leaching. A third advantage to organic materials is that you can sometimes find free or inexpensive sources, if you take the time to search for them. Many livestock producers and industries that produce organic wastes are required to properly dispose of their byproducts and are more than happy for you to take some of this material off of their hands.

One of the disadvantages is that, depending on the source, organic materials are more difficult to apply than inorganic fertilizers. Organic fertilizers are usually lower in nutrient content, therefore requiring more material to be applied to acquire the same amount of nutrient from an inorganic source. Most organic materials can only be applied by hand unless you have access to some kind of specialized, mechanical applicator. Secondly, the slow-release property of the nutrients, which can be a benefit, can also be a detriment. If not applied properly and in a timely manner, the nutrients can be tied up in the organic matter and not be available to the plant, therefore, it is advisable to apply these materials well in advance of the need for the nutrients so that there will be enough time for the material to break down. Finally, the nutrient contents of organic fertilizer materials can be highly variable and makes it difficult to determine the proper amount to apply.

Because of the last disadvantage, I recommend that you have your organic fertilizer sources tested for its nutrient content. This will tell you how much of the essential nutrients are available to the plant and how much material to apply. In North Carolina, NCDA will test your materials for $ 4.00 per sample. If you use organic materials in large quantities the cost of analysis is well worth it. This will allow you to reap the fullest benefit of your fertilizer by applying it in the proper amounts. Keep in mind, however, that you may not be able to apply all of the nutrients in the proper amounts. The nutrient ratios don't come out in nice even numbers like 5-10-5 or 10-10-10, so you may have to supplement organic materials with some inorganic fertilizers to get the proper amounts of all nutrients.

I recommend that you use organic fertilizer materials when possible. The addition of organic matter to your soil, especially if it is sandy, can lead to remarkable benefits. Also, you are making use of material that would otherwise be discarded. Just be sure that you use them wisely; have your soil and fertilizer sources tested for nutrient content so that you can apply them properly.

Visit the following pages for information on various animal manures; dairy, poultry and swine. Visit this site for information about municipal waste.

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For questions regarding Organic Fertilizers, e-mail me!

Date Created 9/15/98.
Revised 2/26/02.