Manure is used as fertiliser in organic agriculture. But there is the question, fresh or composted? Composting is an aerobic process. With high humidity and temperature, the microorganisms in the pile oxidize the organic matter. With this process, we avoid some disadvantages that fresh manure has.
Advantages of fresh manure
The advantage of fresh manure is that it has a higher ammonia content. Therefore, it enriches the soil with higher amounts of nitrogen. However, it must be incorporated into the soil. The nitrogen in fresh manure is highly soluble. Therefore, if it is not incorporated into the soil, the nitrogen will be lost to the atmosphere.
Disadvantages of fresh manure
Apart from the need for incorporation, the use of fresh manure has other disadvantages. First, there is a serious risk of carrying weed seeds as well as disease. The problem becomes particularly serious when these diseases or weeds were not previously present in our soil. In addition, there are usually large amounts of salts, which can damage our plants. Finally, fresh manure can also carry pathogens that infect humans. Particularly in plants where the edible part of the plant is in the ground, the application should be made at least 4 months before harvest.
In order to avoid the above serious disadvantages, composted manure is used. It is lighter since it has less moisture, and is easier to move. Also, the composting process kills most weed seeds and pathogens. Still, it is not necessary to incorporate it into the soil. However, the disadvantage is that it has a lower concentration of nitrogen. So, the needs of the plants are not easily met.
In conclusion, it is preferable to apply composted manure. In addition, it is recommended that it be certified. This way you have an idea of the nutrients it contains. Also, the risk of the above mentioned disadvantages is significantly reduced.