Characterization of Biochar Produced from Diverse Feedstocks Used as Amendment on Acidic Ultisols at Umudike, Abia State.

Biochar is used as a soil amendment to improve soil nutrients for crop production. The nutrient contents of biochar depend on the type of feedstock, pyrolysis types and temperature among others. In this study, it was hypothesized that biochar produced from different feedstock at the same temperature will have different effects on soil properties. To verify this, a pot experiement was set up at the Experimental Field of College of Crop and Soil Sciences of Michael Okpara University of Agriculture, to determine the effect of the biochar from twelve different feedstocks on soil chemical properties. The twelve types of biochar produced were from Bone, Cow dung, Mixed feedstock, Cocoa pod, Goat droppings others were Palm bunch, Pig waste, Poultry droppings, Saw dust, Rice mill husk, Ukpo shell (Mucuna flagellipes) and Wood shaving. These biochar types and a control without biochar served as the treatment, they were produced with the pyrolysis drum at the temperature of 450 0 C. The treatments were applied at the rate of 3 t/ha (whose equivalent was 86 g) to 10 kg of soil weighed into pots and replicated 4 times in a Completely Randomized Design. The effects of the treatments were determined on the soil pH, exchangeable acidity, available phosphorus, total nitrogen. Others were organic carbon, exchangeable potassium, sodium, calcium and magnesium using the standard laboratory procedure. Biochar produced from mixed feedstock significantly (p<0.05) increased the soil pH from the pre-treatment pH value of 4.8 in water to 6.8. Soil total nitrogen was significantly increased to 0.15 % by the application of ukpo shell biochar while biochar produced from pig waste significantly reduced the soil exchangeable acidity to 0.50 cmolkg-1 from 1.96 cmolkg-1 of the pre-amended soil. The result showed that different feedstocks subjected to same pyrolysis temperature would produce biochar that will affect the soil chemical properties differently in a pot experiment. Further trail on the field with the treatments is recommended.