Biological Effects of Biochar and Fertilizer Interaction in Soybean Plant

The effect of biochar, as a soil amendment, in combination with different concentrations of a chemical fertilizer on the agronomic traits and physiological characteristics was investigated using the soybean cultivar Tiefeng 40 during 2010 and 2011. The results revealed that the application of biochar mixed with fertilizer increased the plant height, net photosynthetic rate, and leaf transpiration rate, and also improved the leaf and stem dry matter accumulation. Although the effect of biochar mixed with fertilizer on N(nitrogen) and P(phosphorus) uptake in soybean was not obvious during the early growth stage, both leaf and stem N and P uptake gradually increased in the late stage, and the accumulation per plant for both N and P was also significantly improved. Moreover, biochar mixed with fertilizer increased the pod number, seed number, and seed size per plant, resulting in an average yield increase of 13.2%, compared with the treatment of applying chemical fertilize alone. As the fertilizer application was reduced by 15%, 30%, and 60%, the yield increased by 11.20%, 11.00%, and 8.17% respectively, with a yield increase of 10.6% on an average of two years. Meanwhile, the increase in total protein and fat contents was also dependent on the concentration of biochar mixed with fertilizer, the greater the biochar concentration, the greater the increase. Taken together, our results support the theory of less fertilizer, but positive effects for both yield and quality in Tiefeng 40. This approach can be applied in soybean production.