Composted Livestock Manure Produces Nutrient-Rich Fertilizer

As the population grows, fertilizers for crops and pasture grass are increasingly in demand including the potential of packaged cow manure as compost fertilizer for retail and commercial applications.
Organic cow manure is a nutrient that helps crops and pasture grass production over longer durations before the need for reapplication because of its slow release of nutrients.  “Dairy cow manure is a nutrient-rich, all natural fertilizer that holds moisture in the soil and reduces erosion more effectively than synthetic or chemical fertilizers,” says Dr. Pius Ndegwa, Washington State University   Biological Systems Engineering School Associate Professor and livestock manure specialist. “We are working with dairy farmers to develop channels to apply nutrient-rich manure as compost fertilizer for the production of crops and pastures at appropriate agronomic rates to protect groundwater quality.”  
WSU Extension is modeling digestion and composting systems at many Washington dairy operations to help ensure the integrity of lined-lagoons and that anaerobic protocols are followed to prevent nutrients from being wasted.  More organic matter in the soil improves its moisture-retention performance.
“Livestock manure compost is cheaper and easier to use than man-made chemical fertilizers,” says Bob Ashbeck of Columbia Basin Spreaders, in Hermiston, Oregon. “The livestock compost is a renewable resource that contains all of the nutrients plants need to grow with none of the chemicals.  It is being widely used to fertilize potatoes and pasture grass.”
Seattle’s Woodland Park Zoo is located in the heart of a city where composting animal waste has been ongoing since 2010.  This year the Zoo will sell more than 1 million pounds of Zoo Doo as an all-organic, dark and rich compost fertilizer, saving the Zoo $60,000 per year in disposal costs. 
According to Woodland Park Zoo recycling and compost coordinator Dan Corum, the manure comes from the Zoo’s non-primate, herbivore animals (those that eat plants), including elephants, hippos, zebras, giraffes, gazelles and oryx, among others.   Zoo Doo manure has the same characteristics as cow manure.
Similar to livestock manure composting, Woodland Park's Zoo Doo process begins when fresh manure and straw bedding are collected from animal enclosures, then mixed with organic materials such as leaves and wood chips. The material is watered and piled into long rows where its temperature climbs naturally to 150+ degrees, destroying any pathogens it contains.  After three months Zoo Doo cools, becomes dark and crumbly and is ready for use in home gardens.
“Zoo Doo or composted livestock manure added to soil enhances water and nutrient retention and will improve soil texture,” Corum said. “It is a completely organic soil amendment that will help crops, pastures and home gardens grow.”
Although consumers should not expect "Moo Doo" at stores any time soon,  Chuck Phillips, of Bark Boys Landscape in Mead, WA, is increasing sales of livestock compost to retailers as a consumer fertilizer.  “Cow manure compost is popular and widely used in annual and perennial gardens because the consumer sees results fairly fast,” he says.  People are more aware of applying chemical fertilizers so people want to use organic which is closer to nature.”
The chemicals in synthetic fertilizers are available for only a short time as compared to the slow release of the nutrients in livestock manure.
Dr. Pius Ndegwa, WSU Associate Professor of Land, Air & Water Resources and Environmental Engineering (LAWREE) conducts research with an emphasis on sustainable livestock manure management systems; air and water quality control engineering; bio-energy or bio-fuels; and livestock odor emission control technologies. He is also one of the coordinators for the Western Region Odor & Air Quality Program (WOAQ). Since the 1970s the WSU Biological System Engineering School has been active in technical environmental stewardship, research and education, with a current emphasis on biological waste analysis and treatment; chemical transport through soils; food engineering; bioenergy and bioproducts, among other engineering areas of interest.
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