Eco-friendly and efficient management of solid animal manure

Manure has for centuries been used as a fertilizer to grasslands and for crop production in most farming systems. Unfortunately, poorly managed recycling of manure to land poses an environmental risk especially due to the content of nitrogen (N), organic carbon (C) and water - components that are substrates for the microbial production of the two greenhouse gases, nitrous oxide (N2O) and methane (CH4), and also for the pollutant ammonia (NH3) that is a risk to oligotrophic ecosystems and to human health. The two greenhouse gases may be produced and released from each stage of the manure management chain, which are: (1) livestock building/beef feedlots; (2) manure stores; (3) manure treatment; and (4) manure application to land. Management of the manure can greatly affect the emission of these gases through control of environmental parameters (temperature and water availability) and the removal of carbon. This chapter presents the processes involved in the production and emission of these gases, of the emission rates and how these are affected by manure management, and finally it gives examples of management chains that cause high and low releases of the gases to the atmosphere.