Acidified Carbon with Variable Irrigation Sources Impact on Rice Growth and Yield under Cd Toxic Alkaline Soil Conditions

Abstract

Cadmium (Cd) is one of the potential carcinogenic toxins for humans, plants, and animals. Higher uptake of Cd in plants causes a significant reduction in productivity that can be remediated using organic amendments. Biochar can absorb Cd and decrease its toxicity. However, the high pH of biochar minimizes its adaptation as an amendment in alkaline soils. As Cd is highly soluble in water, its uptake in rice is a major issue. That is why the current experiment was conducted to examine chemically produced acidified carbon (AC) effectiveness in alleviating Cd-induced stress in rice. There were three levels of Cd (0, 4, and 8 mg kg−1 soil) applied with three levels of AC (0, 0.5, and 1%) for the cultivation of rice irrigated with ground water (GW) and waste water irrigation (WW). Results confirmed that applying 1% AC improved plant height, spike length, and 1000 grains weight over 0% AC under GW and WW irrigations at 8 mg Cd kg−1 soil (8Cd) toxicity. A significant increase in photosynthetic rate, transpiration rate, and stomatal conductance by 1% AC validated its effectiveness in alleviating 8Cd stress in rice under GW and WW. Overall, 1% AC is an effective amendment in alleviating Cd toxicity in rice irrigated with GW and WW at 8Cd. More investigations are recommended at the field level to declare 1% AC as the most effective application rate for mitigating Cd stress in rice.