Biochar Incorporation Enhances Growth, Yield, and Water Productivity of Transplanted Rice under Alternate Wetting and Drying Irrigation
摘要
Sustainable rice production under changing climate faces several challenges, including deteriorating soil fertility and water scarcity, resulting in low productivity. To address these issues, improved and appropriate crop management approaches are fundamental. Biochar as an organic amendment and alternate wetting and drying (AWD) irrigation as a water-saving technology hold immense potential in this regard. The current study aimed at investigating the impact of biochar on growth, physiological traits, yield, and water productivity of transplanted rice under AWD irrigation. A factorial experiment consisting of five biochar doses (0, 5, 10, 15, and 20 t ha−1) and three soil water potential levels (0, − 15, and − 30 kPa) maintained through AWD irrigation was conducted. Incremental biochar doses improved crop performance, and the best results were observed at 20 t ha−1. The performance of rice (growth, physiological traits, and yield) was largely similar between 0 (sufficient soil moisture availability) and − 15 kPa soil water potential levels; however, − 30 kPa significantly damaged rice as it reduced leaf relative water content by 21%, membrane stability index by 13%, and net photosynthetic rate by 11%, ultimately reducing grain yield by 10% in comparison to 0 kPa. Conversely, − 15 kPa did not show any notable abnormality, rather this soil water potential level was beneficial for some tested parameters. Interactively, biochar application at 20 t ha−1 and AWD irrigation at − 15 kPa demonstrated the overall best crop performance in terms of yield enhancement (~ 25%) and water productivity improvement (~ 70%). The inclusion of biochar in a fertilizer management program and AWD irrigation as a water-saving technology is recommended for transplanted rice cultivation to curtail the detrimental impacts of depleting soil fertility and water-deficit stress.