There is a little problem with manure. Barry Olson of Alberta Agriculture said recommended spreading rates in terms of volume per acre are not as important as knowing the actual chemical content of the manure. This is followed up with a detailed soil analysis to prevent overapplication and potential damage to plants. Overloading the soil with manure increases electrical conductivity, which indicates a salt buildup. Another problem is the inconsistency of manure content, which can depend on climatic conditions, animal species, storage systems, feed rations, moisture content and types of bedding material.
Manure is an organic fertilizer but plants can only use inorganic nutrients.
Transformation from one to the other takes time, which means only a portion of nutrients are available to the plant during the first year of application. Solid manure takes longer to release nutrients than liquid manure. One problem with nitrogen is that it can be converted to gas and lost to the atmosphere. It can also leach through the soil beyond the root zone so it is no longer useful to plants. Studies have found that injecting liquid manure or working solid manure into the soil as soon as possible are the best ways to prevent some of these problems.