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 degrees 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 degrees C significantly increased plants roots dry weight in the sandy-loam growing substrate (52% compared to the control). Grain production was also significantly affected by biochar application, showing better results after addition of biochar produced at 400 degrees C. Water holding capacity and K, Ca, and Mg contents were enhanced by biochar addition, with evident effects of the application ratios for some of these variables. The effect 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 degrees C.