Manure Slurry Transport and Land Application Rates for Tank Spreader Systems

Abstract

Accurate estimates of the hauling capacity of spreader tank systems are needed to create valid models which give meaningful comparisons between system alternatives. In the last several years livestock farms in the Great Lakes Region have expanded and increased in size. With more livestock comes more manure handling and a greater transport distance to reach the land base needed for land application. Because hauling and spreading large volumes of manure can greatly impact peak labor demand and the timeliness of tillage and planting, many farm managers are using custom hire of manure hauling and land application. A time-and-motion study of thirteen liquid manure hauling systems on ten farms using custom hauling services in Michigan, Ohio and Ontario, Canada was done in 2006-2008. Representative time and material flow rates were used to model the hauling capacity of tank spreader systems as a function of spreader tank volume and transport distance. Simulated hauling rates were fit to a general model to develop machinery system-specific coefficients to predict an effective hauling capacity of tractor-drawn and truck-drawn spreader tanks, and hauling systems using truck-drawn nurse tanks for over-the-road transport to tractor-drawn spreader tanks for field spreading. Compared to standard tractor-drawn tank spreaders, spreaders drawn with high-speed tractors and truck-drawn or truck mounted spreaders had an advantage with longer hauls. Compared to injection with a 6-shank injector a broadcast application with a 7000 tractor-drawn spreader (high-speed tractor) increased the hauling rate 25% near storage and 17% with a 2 mile haul. The hauling rate of tank spreader systems was most sensitive to an increase in tank volume and travel speed. A 20% increase in tank volume increased the effective hauling rate about 8% with a 0.1 mile haul and more than 16% with a 10 mile haul. A 20% increase in travel speed had little effect when hauling near storage, but increased the hauling rate more than 7% with a 2 mile haul, and more than 14% with a 10 mile haul.