Combined Effect of Prickly Pear Waste Biochar and Azolla on Soil Fertility, Growth, and Yield of Roselle (Hibiscus sabdariffa L.) Plants

Abstract

Although the use of biochar to promote plant growth has been reported by many researchers, the combined effect of prickly pear waste biochar (BC) and Azolla (AZ) in a field experiment on the roselle plants did yet receive attention. Therefore, the study aims to evaluate the effect of biochar and Azolla extract on the growth, production, and quality of roselle plants. The experiment treatments were in a completely randomized block design with three replicates. Biochar was added at rates of 0, 10, and 20 ton ha−1 and AZ was applied at rates of 0, 3, and 6% in addition to a control treatment. Biochar added at high rate (20 ton ha−1) significantly increased the fresh and dry weights of sepals by 27.98 and 35.73%, respectively, compared to the control. The corresponding values were significantly increased by 11.89 and 11.85% over the control when Azolla was added at rate of 6%. The interaction effect of both BC and AZ treatments at high rate significantly increased the fresh and dry weight of sepals by 47.16 and 60.59%, respectively, compared to the control. The interaction effect of BC and AZ realized significant effect on soil properties, growth and yield, as well as pigments of roselle plants. This is a good evident means that BC and AZ applications separately or combined are considered promising materials for sustainable organic agriculture and safety food.

Effect of various biochar on selected soil properties and agronomical parameters of okra (Abelmoschus esculentus L.) at Rupandehi, Nepal

“…Biochar can quickly release base cations like Ca 2+ , Mg 2+ , and K + to the soil solution and lower H + and Al/ Ca ratio due to its alkaline nature, which increases soil pH (Al-Sayed et al, 2022;Cornelissen et al, 2018). Additionally, biochar contains reactive pH-dependent functional groups like phenolic (OH) and carboxylic acid (COOH), which may raise the pH of the soil (Al-Sayed et al, 2022). Similar relationship between biochar and soil pH was obtained in previous findings (Dahal et al, 2021;Farias et al, 2020).…”

“…The increased amount of alkaline earth metals and decreased amount of acidic organic moieties is another reason for increasing the pH of biochar (Gezahegn et al, 2019). Biochar can quickly release base cations like Ca 2+ , Mg 2+ , and K + to the soil solution and lower H + and Al/ Ca ratio due to its alkaline nature, which increases soil pH (Al-Sayed et al, 2022;Cornelissen et al, 2018). Additionally, biochar contains reactive pH-dependent functional groups like phenolic (OH) and carboxylic acid (COOH), which may raise the pH of the soil (Al-Sayed et al, 2022).…”