Effect of vermicompost and biochar application on microbial activity of soil under deficit irrigation

Climate change is a growing global threat to biodiversity and ecosystems. In this study, we aim to find a solution to sustain soil microbial life under water shortage that occurs as a result of climate change. In this study, tomato plants were grown under full and two-stage limited irrigation conditions in soil treated with vermicompost and biochar. An insignificant effect of irrigation regime and planting application on soil respiration (BSR) value could be determined. Compared to the control, no difference could be detected with ECOF applications in unplanted soils under full irrigation conditions. While the dehydrogenase (DHG) activity of the unplanted plots was determined as 14.35 μg TPF g-1, the determination of the planted plots as 12.52 μg TPF g-1 can be considered as an expression of the fact that the microorganisms in the soil are less exposed to cultural processes in tomato cultivation and support to increase their populations. In Full irrigation and Deficit 1 application in unplanted soils, DHG activity at the level of 14.08 and 17.58 μg TPF g-1 was obtained, respectively, with the addition of biochar, followed by control plot in Full irrigation application and vermicompost application in Deficit 1 application. In Deficit 2 application, biochar application made a significant difference compared to the other two applications and caused activity of 34.91 μg TPF g-1 (P<0.05). With these results, it has been revealed that even at limited moisture levels, biochar applications with high porosity content can provide a lifetime opportunity to microorganisms. In conclusion, it can be stated that vermicompost and biochar applied at the level of 10 t ha-1 can support the microbial activity in the soil under limited irrigation conditions, and biochar application contributes more when the soil moisture is reduced to 15%.