Can biochar retain water holding capacity in United Arab Emirates (UAE) soils?

Water scarcity has a huge impact on global food security, particularly in countries with arid climates and less fertile soils. Recently, there has been increasing interest in the production of biochar from agricultural wastes as a potential solution for improving soil quality. Studies have shown that biochar can enhance carbon sequestration, plant growth and soil pH. Although there are many reported benefits of biochar, there has been limited research into the behaviour of biochar in arid environments, where water retention is a critical factor in improving soil health. The aim of this research was to investigate the potential of Date Palm Fronds (DPF) and biochar to improve water holding capacity and plant growth in the context of an arid climate. The aim was approached by 4 main experiments: 1) Investigate the physiochemical properties of the materials; 2) A mesocosm experiment to measure the water holding capacity of the soils with biochar amendments; 3) Pot trial experiments to evaluate plant growth, and 4) Analysis of water retention using Thermal Gravimetric Analysis (TGA). The experiments took place in two different locations: the Department of Earth Science in Durham University, UK and the United Arab Emirates (UAE), Abu Dhabi. UAE sandy soils were amended with both date palm fronds and biochar derived from DPF. The effects of the treatments were assessed using Analysis of
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Variance (ANOVA). The results demonstrate that biochar improves plant growth and soil quality, while DPF can be equally effective and in some cases more effective in enhancing water retention. Biochar exhibited greater porosity, a higher carbon to nitrogen ratio and increased thermal stability compared to DPF. Both biochar and DPF enhanced soil moisture retention, with biochar showing greater effectiveness during wet cycles and supporting plant growth under extreme conditions. The combined application of biochar and DPF further improved soil moisture and plant growth, with lower application rates proving more effective.
These findings support the use of biochar and DPF as a sustainable soil amendment to address water scarcity and soil degradation in arid regions. Further research should focus on long-term field studies as well as the economic and environmental implications of large-scale biochar application. This study provides valuable insights into using biochar and DPF for sustainable soil improvement and agricultural productivity in a challenging environment.