Effects of Adding Coconut Charcoal on Soil Physical Properties and Maize Performance

抄録

Tonga is a tropical nation that faces susceptibility to the effects of climate change, with one of the primary challenges for its agricultural sector being the impact of El-Nino leading to prolonged periods of drought. The resulting economic crisis in the region was notable during the 2015-2016 drought season, leading to food shortages and a subsequent increase in food prices. This necessitated the importation of more expensive perishable goods to supplement locally produced items. This study aimed to investigate the use of coconut charcoal as a soil water amendment to mitigate water scarcity during drought periods. The findings demonstrated that incorporating 10 % of coconut charcoal with particle sizes of less than 1 mm into the soil can enhance soil physical properties, particularly in terms of maintaining optimal soil water levels of 50 kPa to 100 kPa for plant vegetative growth and grain growth 100 kPa to 1200 kPa. This amendment was found to alleviate plant water stress by prolonging the period before soil dryness occurs, benefiting vegetative growth and grain development stages. In conclusion, the incorporation of coconut charcoal as a soil amendment showed significant improvement in overall plant performance, such as an average increase in leaf area from 33.7 cm² to 93.9 cm². This suggests that coconut charcoal can be a viable recommendation as a soil amendment, aiding in the conservation of water resources and reducing irrigation costs and other expenses for small-scale farmers. This approach could enhance the resilience of Tonga’s agricultural sector and small farmers in coping with drought conditions attributed to El-Nino. Consequently, this strategy could help diminish the need for importing perishable agricultural products from abroad during drought periods.