Effects of Biochar Application in a Sorghum Crop under Greenhouse Conditions: Growth Parameters and Physicochemical Fertility

Application of biochar from vine shoots (Vitis vinifera L.) as an organic amendment in the
soil is an alternative agricultural management of interest. The behavior of this type of amendment in
the soil requires more information to adjust the pyrolysis conditions in order to obtain a high-quality
biochar. The aim of this work is determining the influence of the application of this type of biochar
on the soil-plant system. For this purpose, an agronomic test was performed in greenhouse pots.
A randomized tri-factorial block design was adopted with the following factors: final pyrolysis
temperature (400 and 600 C), application rate (0 wt. % as a control, 1.5 and 3 wt. %) and texture of
the growing media (sandy-loam and clay-loam origin). The selected crop was sorghum (Sorghum
bicolor L. Moench), the development and production of which was evaluated during two complete
growing cycles under greenhouse conditions. Application of biochar produced at 400 C significantly
increased plants roots dry weight in the sandy-loam growing substrate (52% compared to the control).
Grain production was also significantly a ected by biochar application, showing better results after
addition of biochar produced at 400 C. Water holding capacity and K, Ca, and Mg contents were
enhanced by biochar addition, with evident e ects of the application ratios for some of these variables.
The e ect on the pH of substrates in the sandy-loam texture was weak; however, a significant decrease
was observed after the addition of biochar produced at 600 C.