Hydrochar from sugarcane industry by-products: assessment of its
potential use as a soil conditioner by germination and growth of maize
CHEMICAL AND BIOLOGICAL TECHNOLOGIES IN AGRICULTURE, (2021)DOI: 10.1186/s40538-021-00210-1
Abstract
Background: Hydrothermal carbonization (HTC) is a thermochemical process
to convert biomass in carbon-rich materials (hydrochar). The use of
sugarcane industry by-products in HTC has been evaluated, generating a
hydrochar rich in nutrients, which could be used as a soil conditioner.
We raised the hypothesis that the application of hydrochar in soil can
improve its nutrient characteristics, bringing a better environment and
favouring plant growth, expecting a development similar to that one
observed in anthropogenic soils.
Results: Germination studies were performed expecting a
species-dependent response, using maize and tomato seeds, whose
development was assessed in two soluble fractions obtained from
hydrochar aiming to evaluate different rhizosphere conditions. The
results showed a better development of maize, especially in the aqueous
soluble fraction, whose nutrient concentration was lower than that of
the acid soluble fraction, as well as the organic composition. Maize
growth in soils showed a better initial development in ultisol compared
to oxisol, this being inferred by root:shoot biomass ratio and by
scanning electron microscopy (SEM) images. However, the development of
maize was better in anthropogenic soil compared to soils that received
hydrochar.
Conclusion: The maize growth, compared with that carried out in
anthropogenic soil, suggests that during the period evaluated the
addition of hydrochar in soil did not have a negative effect upon maize
development in its initial phase, and could have even favoured rooting
in ultisol.