Enhancing Livestock Manure
by David Widman, ProfitProAG Consultant
While the growing movement towards using livestock manure as a crop nutrient source increases, understanding the process of manure decomposition during storage allows producers to enhance their manure management strategies.
The key benefit of properly stored manure is to enhance its value as a crop fertilizer and improve soil health. After consumption by the animal, the digestion process starts the decomposition and the end result is manure. Nature then provides the mechanisms to breakdown the manure and urine after it is applied to soil via the soil biology. When raw manure is applied to soil, the soil biology focuses first on breaking it down for incorporation into the soil profile—a process that can take up to four months. Since the focus of soil biology is on manure digestion rather than helping the crop grow it affects the rate of growth due to low nutrient availability.
Stored manure is always in some stage of decomposition, which can either be a favorable process or a detriment that creates more toxins that the soil biology has to neutralize to maintain a balanced soil profile.
Biology in the manure from the animal’s digestion continues the breakdown process. However, additional biology in the soil (fungal groups) is also involved for a more complete nutrient cycling. The key to making manure a friendly soil amendment that will work with and enhance the soil biology is to have the correct biology during storage. These microbes in the manure are facultative meaning they continue to work in the soil after application. Their main goal is to use the organic material as food for themselves. As they reproduce and increase in population, nutrients are recycled by these microbes, which lock up the nitrogen, sulfur, phosphorous, potassium, magnesium, manganese, iron, copper and various other nutrients in a form that is stable and available to plants.
Another critical key of manure storage is to have the correct pH as this dictates which microbes are working. The range is 6.5 to 7.5 with 6.8 to 7.2 being the optimum for proper manure digestion. Digesting microbes work in this range, which relates to the optimum soil pH—6.5 to 7.0—that produces the best crops. When the pH is under 6.5, the decomposition process decreases and can leave manure thicker depending upon the animal’s diet. When the pH is over 7.5, the methanogen microbes can become active and create methane gas, which can cause barn explosions and fire. Feed ingredients impact the pH of the manure and can make the pH either lower or higher from the desired range. Water can also affect manure pH. When the pH is out of range, toxic gases and other undesirable microbial byproducts are created thus making dangerous environmental conditions for livestock and humans.
Follow the Steps to Success
Manure management is complicated when the basic manure fundamentals are not understood. Knowing the pH of the water and feed for the livestock is the first step and provides direction for properly balancing the manure during storage. Next know the pH of the liquid manure in the storage facility and monitor it on a regular basis (at least every six weeks). The manure pH dictates the correct pH, which enables the proper microbes to do their job. Follow this step with the introduction of microbes that decompose manure. After the microbes are started, bubbling indicates working activity. Also the manure will stay more liquid with very little top crust. It’s important to routinely check the pH of the manure so the manure remains biologically active.
ProfitProAG offers live culture microbes and dry organic products coupled with the knowledge to help enhance manure management. Services are available for manure treatment by either a local rep or a self-treatment plan. For more information on manure management, call ProfitProAG at 1-888-875-2425.