PHYSICAL AND RHEOLOGICAL PROPERTIES OF MANURE PRODUCTS

Abstract

Selected physical and rheological properties deemed to influence the performances of handling and land application equipment were quantified for different types of manure at different levels of total solids concentration (TS) ranging from 10% to 50% on a wet mass basis. The selected properties included total solids concentration, bulk density, particle size distribution, friction characteristics, and shearing behavior and were measured for dairy cattle, sheep, poultry, and pig manure. The bulk density of all manure products was found to increase with TS and the values for poultry and pig manure were not significantly different at the tested TS levels. The measured density values were in close agreement with ASAE D384. The proposed modified geometric mean length of the particles was found to significantly increase as TS became smaller. The static friction coefficients of all manure types with the exception of pig manure on the different surface materials [plywood, plastic, steel (bare and painted )] did not exhibit large differences and a single linear equation was suggested to predict the static friction coefficient as a function of TS. Animal manures were described as pseudoplastic fluids and the consistency coefficients were found to increase with TS for all manure types. The apparent viscosity of the tested manure products was well correlated to TS. The implications of the property results obtained in this study as well as future research are discussed.