LAUSR

Few studies have evaluated biochar application rates that would make economic sense using feedstocks readily available to subsistence farmers. Biochar from livestock manures were examined in Oakleaf and Tukulu soils. Pyrolysis had the most effect on poultry manure where it increased pH (7.8%), electrical conductivity (19.8%), total phosphorus (31%) and zinc (23.9%). Maize germination percentage in Oakleaf soil was enhanced more under cattle manure biochar (CMB) at 100 kg C ha−1, which differed from the control by 14.29%. In Tukulu soil, CMB at 400 kg C ha−1 enhanced germination percentage more and this increase was 22.50% higher than that of the control. In Oakleaf soil, 100 kg C ha−1 was optimal to increase plant height under sheep manure biochar (SMB), goat manure biochar (GMB), and poultry manure biochar (PMB), whereas 400 kg C ha−1 was optimal under CMB; however, in Tukulu soil 100 kg C ha−1 was optimum under GMB and CMB. The difference from the control in plant biomass was highest (28.06%) under SMB at 400 kg C ha−1 in the Oakleaf soil, whereas in Tukulu soil SMB at 300 kg C ha−1 produced the highest (19.03%) plant biomass. Overall, CMB provided a better alternative for use in Tukulu and Oakleaf soils, but field trials need to be conducted.