S. I. BIOCHAR Ecophysiological response of early stage Albizia lebbeck to cadmium toxicity and biochar addition Muhammad Talha Bin Yousaf 1 & Muhammad Farrakh Nawaz 1 & Hammad Fayyaz Khawaja 1 & Sadaf Gul 2 & Shafaqat Ali 3 & Irfan Ahmad 1 & Fahd Rasul 4 & Muhammad Rizwan 3 Received: 6 November 2018 /Accepted: 1 February 2019 # Saudi Society for Geosciences 2019 Abstract Cadmium (Cd) toxicity is among the most prominent issues regarding land degradation. Traditional approaches for soil reme- diation are not effective. However, phytoremediation is described as the most efficient, economical, and sustainable approach to combat with terrestrial heavy metal pollution. Moreover, if phytoremediation is used in combination with soil amendment, its effectiveness can be increased several folds. Among soil amendments, biochar is considered the best amendment due to its potential for remediation and plant growth. The objective of this study was to determine the phytoremediation potential of Albizia lebbeck in Cd-contaminated and biochar-amended soils. A pot experiment was planned to test the ecophysiological response and Cd uptake of 3-month-old uniform-sized Albizia lebbeck seedlings. Cadmium was induced in soil through irrigational water at the rate of 25 mg/L. Two concentrations of biochar were used: B 1 (3%) and B 2 (6%). A total of six treatments were applied: Cd 0 B 0 (T1), Cd 0 B 1 (T2), Cd 0 B 2 (T3), Cd 1 B 0 (T4), Cd 1 B 1 (T5), and Cd 1 B 2 (T6), where, Cd 0 and B 0 designate the control treatment. The plants were harvested after 4 months of growth in the soil with amendments. The maximum growth and gas exchange charac- teristics were showed by the plant of T3. Cadmium toxicity reduced the growth and gas exchange characteristics to a great extent. Plants of T4 showed the minimum growth compared to the other amendments. The addition of 6% biochar in Cd-contaminated soil (T6) resulted in the decent increase in the growth of plants. The maximum root length (67.18 cm) and shoot length (80.06 cm) were observed in the plants of T3, whereas, the minimum root length (13.94 cm) and shoot length (35.03 cm) were observed in the plants of T4. This study suggests that biochar can be used to enhance the growth of agroforestry tree species like Albizzia lebbek in Cd-contaminated soils. Keywords Heavy metal toxicity . Phytoremediation . Albizzia lebbek . Biochar . Agroforestry Introduction Heavy metal soil contamination is one of the major concerns while addressing the global challenges of food security and safety (Hou and Li 2017). Polluted soils act as a store of contaminants and these contaminants are taken up by living organisms like plants. The plants, being primary producers, when consumed by animals and human, act as a source of heavy metal accumulation in the bodies of consumers. Finally, these contaminants enter into food chain and cause several harmful effects at larger scales (Adrees et al. 2015a; Abbas et al. 2018). Furthermore, these contaminants from polluted soils can also be leached into water bodies that can result in their transfer from one place to other areas (Rehman et al. 2017). Novel ideas and techniques are being frequently employed to alleviate the hazardous effects of these contaminants; however, there is still a wide gap in resolving this problem. There are several harmful effects of contamination of lands. The overall production of crop yield is badly affected by these contaminants. Like many other hazards, the major problem with the pollution of lands is that the usage of the crop This article is part of the Topical Collection on Implications of Biochar Application to Soil Environment under Arid Conditions * Muhammad Rizwan mrazi1532@yahoo.com 1 Department of Forestry and Range Management, University of Agriculture, Faisalabad, Pakistan 2 Department of Botany, University of Karachi, Karachi, Pakistan 3 Department of Environmental Sciences and Engineering, Government College University, Allama Iqbal Road, Faisalabad 38000, Pakistan 4 Department of Agronomy, University of Agriculture, Faisalabad, Pakistan Arabian Journal of Geosciences (2019) 12:134 https://doi.org/10.1007/s12517-019-4296-1