Short term effect of biochar incorporation on selected chemical properties of a highly weathered coastal savanna soil

Short term effect of biochar incorporation on selected chemical properties of a highly weathered coastal savanna soil

The study examined the effects of corn cob biochar or cow dung applied singly or in combination on mineral nitrogen concentration, soil respiration and microbial biomass carbon in a highly weathered soil from the coastal Savanna agroecological zone of Ghana. The biochar was pyrolysed at approximately 350 oC in a Lucia stove. The study showed that only the sole cow dung application significantly increased soil mineral N (NO3- + NH4+) concentrations more than the control, indicating that sole addition of cow dung resulted in net N mineralization while application of biochar singly or in combination with cow dung led to net N immobilization. During the first week of incubation, dissolved organic carbon concentration and soil respiration rates in the combined biochar and cow dung treatments were significantly higher than in the sole biochar or cow dung amended soils. The labile C fraction possibly stimulated larger microbial biomass and higher CO2 emissions from the combined cow dung and biochar treatments, but these increases were short-lived. The study showed that in the short term, independently of whether it was applied solely or in combination with cow dung, corn cob biochar had the potential to improve soil chemical properties and had an influence on the soil N mineralization rate.