Rice husk biochar effects on improving soil properties and root development in rice (<i>Oryza glaberrima</i> Steud.) exposed to drought stress during early reproductive stage

Abstract

<abstract> <p>Benefits of biochar application on environment conservation and agricultural production have been widely studied. However, few studies were focused on root development. The objective of this study covered root and shoot development, yield, and soil properties associated with exposure of <italic>Oryza glaberrima</italic> rice during the early reproductive stage to drought stress in rice-husk amended soil. The biochar was amended at a rate of 10.5 g pot<sup>-1</sup>, equivalent to 3 ton ha<sup>-1</sup>. Biochar-amended and non-amended plants were exposed to drought stress after the panicles had visibly emerged in all plant populations. Biochar application caused less restriction on root elongation, volume, and surface area during water stress conditions. Enhanced root development was primarily associated with improvement in water status and chemical properties in biochar-amended soil. Soil chemical properties improved, including increased soil pH, available P, cation exchange capacity, and exchangeable Mg. Under drought stress conditions, shoot growth was more sensitive than root growth, as indicated by the significant reduction of stem dry weight (SDW) and leaf dry weight (LDW). Fine roots in biochar-amended soil were longer than those in non-amended soil. In general, Biochar application enable the <italic>O. glaberrima</italic> rice to maintain yield under drought stress condition.</p> </abstract>