Effect of Biochar on Immobilization of Cadmium and Soil Chemical Properties

A pot experiment was conducted at Institute of Biotechnology and Genetic Engineering (IBGE), University of Agriculture Peshawar, Pakistan. To conduct the experiment, eight kilograms of air-dried soil were taken in each pot and the amendment biochar was added and mixed properly at different levels like 0%, 1%, 2% and 4% (w/w), respectively. All pots were spiked with Cd solution at the concentration of 10 mg kg⁻¹. The treatments were arranged in completely randomized design (CRD). Fourteen days old nursery plants of rice Oryza sativa L. were transplanted into pots. Five rice plants were grown in each pot. After transplantation of rice plant, the nitrogenous and phosphatic fertilizers (Urea and DAP) were incorporated at the standard rate. Standing water condition was kept for rice grown in pots. Rice plants were harvested after 70 days germination. Soil samples were collected from each pot after plant harvesting. After soil analysis, the given data elaborated that the concentration of Cd in soil was stabilized by the amendment from 8.7 mg kg⁻¹ (0%) to 4.2 mg kg⁻¹ (4%). Among the other soil parameters the minimum soil pH (7.31), EC (0.151 dSm⁻¹), soil organic matter (0.63%), N (0.13%), P (4.72 mg kg⁻¹) and K (55.6 mg kg⁻¹) were noted at 0% biochar application, while maximum pH (8.23), EC (0.231 dSm⁻¹), soil organic matter (1.67%), N (0.25%), P (8.96 mg kg⁻¹) and K (93 mg kg⁻¹) were found in the pot treated with 4% biochar. Hence, it was concluded that Cd was significantly immobilized with 4% biochar application.