The use of soil amendments like biochar and hydrogel offers promising strategies for optimizing water use in agriculture, especially in arid and semi-arid climates where water scarcity is a major concern. A study published in Scientific Reports by Ayman E. Shaban, Hossam M. Moawad, Mahmoud M. Abd El-Migeed, Nagah E. Ashour, and Ahmed A. Rashedy investigated the effects of biochar and hydrogel application on Zebda mango trees in a semi-arid region of Egypt. The research focused on how these amendments influence the trees’ physical structure, nutrient status, yield, and efficiency in using irrigation water over two successive growing seasons. The overarching goal was to identify the most effective treatment for enhancing the performance of mango trees grown in challenging sandy soil conditions, which are typically constrained by low organic matter and limited water-holding capacity.

The experiment compared the impacts of two rates of biochar (7 kg tree−1 and 14 kg tree−1), two rates of hydrogel (50 g tree−1 and 100 g tree−1), and a control group with no application. The results clearly indicated that the soil application of biochar at 14 kg tree−1 was the most beneficial treatment for overall mango performance. This optimal biochar rate led to substantial improvements in the trees’ vegetative growth. Specifically, it increased the number of leaves by 22.27% and 32.05%, leaf area by 18.51% in both seasons, and shoot length by 21.19% and 17.95% compared to the untreated control. Furthermore, this treatment significantly boosted the chlorophyll content, showing an increase of 81% and 51% in the first and second seasons, respectively. Enhancements in chlorophyll content are often correlated with improved photosynthesis and plant health.

Beyond vegetative growth, the 14 kg tree−1 biochar treatment had a pronounced positive effect on the trees’ nutritional status. Leaf concentrations of key macronutrients saw remarkable increases over the two seasons: nitrogen (N) concentration rose by 42.98% and 27.2%, phosphorus (P) by 75% and 47.62%, and potassium (K) by 5% and 9.64%. This improvement in nutrient uptake is likely due to biochar’s porous structure, which enhances water retention, and its high cation exchange capacity, which minimizes nutrient leachingLeaching is the process where nutrients are dissolved and carried away from the soil by water. This can lead to nutrient depletion and environmental pollution. Biochar can help reduce leaching by improving nutrient retention in the soil.   More and improves their availability in the soil. The beneficial impacts on the plant’s physiological parameters, such as increased leaf water content and a decrease in the stress indicator proline, further contributed to the enhanced growth.

The ultimate measure of success for a fruit crop is its yield and quality, and here the 14 kg tree−1 biochar treatment excelled. It significantly improved fruiting characteristics, boosting the percentage of final fruit set by 50% and 38.09% and reducing fruit drop by 2.79% and 2.16%. This led to an impressive increase in the number of fruits by 29.47% and 22.19% and fruit weight by 20.46% and 12.76% in the respective seasons. As a result of these improvements, the fruit yield experienced a substantial increase of 55.98% and 37.79%, and water use efficiency (WUE) saw an identical increase of 55.98% and 37.79% compared to the control in the first and second seasons. This high WUE demonstrates the effectiveness of biochar in maximizing the utilization of irrigation water, a critical outcome in water-scarce semi-arid environments.

The treatment also positively influenced fruit quality metrics. Total Soluble Solids (TSS), a measure of sugar content, increased by 17.09% and 18.27%. Titratable acidity increased by 21.43% and 12.63%, while ascorbic acid (Vitamin C) content was enhanced by 23.56% and 18%. Total sugars also increased by 27.92% and 3.19%. These improvements collectively suggest that applying 14 kg of biochar per tree not only increases the quantity of Zebda mango fruit but also significantly enhances its commercial and nutritional quality. The researchers concluded that the use of this higher rate of biochar, in particular, represents a highly effective and sustainable strategy for improving the growth, nutritional status, yield, and water use efficiency of Zebda mango in semi-arid regions.

Source: Shaban, A. E., Moawad, H. M., Abd El-Migeed, M. M., Ashour, N. E., & Rashedy, A. A. (2025). Morpho-physiological parameters, nutritional status and water use efficiency of Zebda mango in relation to biochar and hydrogel application under semi-arid region. Scientific Reports, 15:41161.