Effect of different biochar sources on wheat grown in Cd contaminated soil

Industrial emissions, anthropogenic activities and the application of both sewage sludge and phosphatic fertilizers to agricultural soils are the major sources of Cd pollution in environment. Cadmium (Cd) contamination is grabbing more and more concern due to its toxicity at very low concentration and high mobility in soil. Wheat is well thought-out to be most important staple crop having great vulnerability to accumulate Cd, even little increase in Cd content in grains could have harmful effects on consumer's health. A pot experiment was conducted to evaluate the effect of different biochar sources on wheat grown in cadmium contaminated soil. The soil was collected from field research area, ISES, UAF. Soil was dried, ground and sieved properly and preserved in the plastic bags. The soil was contaminated with cadmium @ 35 mg per kg of Cd using cadmium sulfate (3CdSO4.8H2O) salt in solution form and was incubated for 90 days at field capacity on the covered plastic sheets. The contaminated soil @ 10 kg per pot along with the designed treatments in their respective pots was filled and placed in the glass house. The designed treatments were rice husk, cotton sticks and wheat straw biochar applied at the rate of (5 and 10 t per ha) on cadmium contaminated soil. There was one control treatment where no amendment was applied but contaminated with Cd. The crop was harvested at maturity and yield was measured. Maximum 1000 grains weight was observed with T6 (35.39 g) where cotton sticks biochar @ 10 t per ha was applied. The soil extract was taken by AB-DTPA and Cd was analyzed by atomic absorption spectrometer. The statistical data showed that maximum immobilization of Cd (mg per kg) was observed in the treatment T5 (4.0496) where rice husk biochar was applied at the rate of 10 t per ha. Minimum Cd (mg per kg) concentration in grains (7.94) in T5. According to results, it is concluded that the biochar has the potential to immobilize Cd concentration in soil and inhibits its uptake by the plants to ensure the food security.