Technical Abstract: Pyrolysis of livestock manures generates a nutrient-rich biochar with potential uses as a soil amendment or alternative fertilizer. This paper reports on selected physicochemical results for five manure-based biochars pyrolyzed at 350 and 700 degrees Celsius: separated swine solids; paved feedlot manure; dairy manure; poultry litter; and turkey litter. Elemental and FTIR spectroscopic analyses of these alkaline biochars confirmed pyrolytic temperature increases led to a reduction in volatile matter and increases in both aromatic-carbon character and ash containing elevated potassium, calcium, and phosphorus. Heavy metal concentrations in all biochars were at acceptable concentrations for land applications, as long as feedstock concentrations were initially acceptable. Manure biochar mass recovery demonstrated an inverse response to temperature increases and strongly correlated to the feedstock proximate (ash and volatile matter) and elemental (carbon, nitrogen) characteristics. Feedstock nutrient concentrations did not affect reactions equally and would not be considered a quantitative predictor of biochar nutrient compositions.