This study investigated the yields and the physicochemical properties of biochar from three different feedstocks viz., i) bioenergy byproducts (deoiled cakes of Jatropha carcus and Pongamia glabra), ii) lignocellulose biomass (Jatropha carcus seed cover), and iii) a noxious weed (Parthenium hysterophorus), obtained through slow pyrolysis at a heating rate of 40 degrees C min(-1) with a nitrogen flow 100 ml min(-1) at a temperature range of 350-650 degrees C. For successful utilization of biochar for C-sequestration, its ability to resist abiotic or biotic degradation was deduced from recalcitrance index R-50 by using TG analysis. It was observed that the biochar produced at higher temperature had higher water holding capacity (WHC) and pH, suggesting its suitability as an amendment in soil with low water retention capacity; thus biochar may be designed to selectively improve soil chemical and physical properties by altering feedstocks and pyrolysis conditions. Biochar produced at 650 degrees C had highest yield in the range of 28.52-39.9 wt.%. (C) 2017 Elsevier Ltd. All rights reserved.