The effect of biochar from plant materials on agricultural acid sulfate soil: a laboratory incubation

The scarcity of suitable arable land has led to the development of acid sulfate soil for cultivation. The major problems of acid sulfate soil are the inherent low pH and available phosphorus (P) as well as the mobilization of toxic elements such as aluminium (Al) and iron (Fe), rendering the soil unfavourable for crop production. The present work aimed to evaluate the effect of biochar from plant materials on the selected parameters of acid sulfate soil in a laboratory incubation, with unamended control and dolomite treatment soils for comparison. The application of biochar signi fi cantly increased ( P < 0.05) soil pH by 0.4 e 0.6 units as well as the soil available P by 13.1 mg kg ¡ 1 relative to the control. The soil exchangeable Al was signi fi cantly reduced (by 2.4 cmol kg ¡ 1 when compared with the control treatment. The dolomite treatment was superior relative to biochar application in increasing soil pH and decreasing Al. The dolomite application, however, was inferior to biochar treatment in increasing soil available P. Moreover, no favourable change was observed in available Fe with the applications of either biochar or lime. These results indicated that biochar has the potential for the amelioration of acid sulfate soil, especially in increasing available P. Further studies should explore the effectiveness of biochar and lime co-application in altering a wider range of soil chemical parameters to inform management options of acid sulfate soil for cultivation.