Integrating by-products from bioenergy technology to improve the morpho-physiological growth and yield of soybean under acidic soil.

Soil acidity may negatively affect plant growth. By-products (bottom ash (BA), biochar (BC), and biogas slurry (BS)) from bioenergy technology may change the physio-chemical properties of acidic soils and affect the plant growth parameters. The current research work was carried out to determine the impact of different bioenergy by-products to enhance soybean growth and production by alleviating the effects of acidic soil. A total of eight treatments of different bioenergy amendments (BA, BC, and BS) and their combined applications were used as follows; T1 (control), T2 (only biogas slurry); T3 (only bottom ash); T4 (only biochar); T5 (biogas slurry + bottom ash); T6 (biogas slurry + biochar); T7 (bottom ash + biochar); T8 (biochar + bottom ash + biogas slurry). Our results depicted that, the synergistic use of amendment mainly, T8 treatment (BC + BA + BS) was found most effective, which significantly prompted the dry biomass and photosynthetic rate by 42.58% and 13.25% over the T6 treatment respectively. Furthermore, the chlorophyll pigments, photochemical activities, and root growth of soybean plants enhanced significantly under T5 and T8 treatments as compared to the control. Finally, amendments significantly increased the yield in T8 treatment by increasing the pod's number, grain number, 100-grain weight and grain yield by 119.6%, 75%, 24.9%, and 83.7% as compared to T1. Conclusively, amendments are very effective in the reclamation of acidic soil and enhance the post-harvest soil pH at T8 treatment by 41.49% in comparison to T1 treatment. The organic amendments might neutralize the soil pH and change the acidic nature of the soil, which would modify the root growth of soybean and increase the photosynthetic and photochemical activities, resulting in increased soybean growth and yield.