Approach to the potential usage of two wood ashes waste as soil amendments on the basis of the dehydrogenase activity and soil oxygen consumption

Abstract

We investigated the effect that ashes may have on the soil microbial activity. Our hypothesis is that different wood ashes and different proportions of them could have beneficial or detrimental effects depending on the applied dose. Dehydrogenase activity and soil oxygen consumption were used to evaluate the potential improvement of soil conditions through the application of two different wood ashes coming from industrial waste. Different ash proportions and time dependence have been used to make comparisons. The respiration curves obtained through a closed-jar incubation experiment were well fitted by a sigmoidal function, the derivative of which yields the time evolution of the consumption rate. The results indicate that the dehydrogenase activity and soil oxygen consumption are very sensitive to the presence of ashes in the soil, and the reached values of both are linked to the applied dose of them. In our research, soil oxygen consumption is time and rate dependent of ash application. The curves show that parameter was affected by the ashes in different way, raising the respiration rate, and stretching the biological activity period. Dehydrogenase activity and soil oxygen consumption are very sensitive to the presence of ashes and can be used to assess their potential use as amendments. The results of this paper can contribute to the required knowledge in order to use ashes in a sustainable way. Ashes coming from olive marc and vine shoots may affect positively the soil respiration and, therefore, the soil fertility, if they are applied in moderate amounts.