Sustainability of ameliorative potentials of urea spiked poultry manure biochar types in simulated sodic soils

Abstract

Abstract Alkaline soil conditions are serious challenges to optimal crop production on irrigated farmlands in arid and semi-arid regions of the world. Unique characteristics of biochar had been utilized in the amelioration of many problematic soils but its use in sodic soil management is not popular in Nigeria. Ameliorative effects of biochar types prepared from poultry manure co-pyrolyzed with or without urea fertilizer were evaluated on soil organic carbon and selected soil chemical characteristics of a simulated sodic soil. The results from the six weeks incubation trial revealed the ability of the biochar types to reduce soil pH from the initial 10.38 to 7.91–10.29 in high sodic (HS) and from initial 9.70 to a range of 7.51–8.39 in low sodic (LS) soil situations compared to 9.88 (HS) and 6.82 (LS) in sole urea treated soil. This accounted for up to 51 and 57% reduction in exchangeable sodium content and percentage (ESP), respectively and 28% increases in exchangeable Ca in the sodic soils. Poultry manure biochar co-pyrolyzed with urea was most effective in reducing exchangeable sodium and ESP in the soils while poultry manure biochar not co-pyrolyzed with urea was highest in reducing soil pH. Poultry manure biochar not spiked with urea was most superior in increasing soil organic carbon in low sodic situation.