Abstract
Aim Chromium (Cr) is a toxic elements and in high concentrations are phytotoxic. This study aimed to test the combined applications of poultry litter biochar and inorganic-fertilizers to ameliorate Cr toxicity.
Methods Biochar, made of poultry litter, was added to Cr contaminated soils (0, 30 and 60 mg kg-1 Cr) either solely or in combination with mineral N fertilizers to ameliorate Cr stress in wheat grown on the contaminated soils for six weeks. A eleven amendments were added to achieve fixed rates of NPK inputs among treatments. Several parameters were used to identify Cr stress coping mechanisms.
Results Root and shoot lengths and their dry weights decreased significantly with increasing Cr contamination level in soil. Under such stressful conditions, the amounts of oxidative stress indicators like Malonaldehyde (MDA) and H2O2 increased considerably. Antioxidants rose significantly in these plants. Biochar and/or NPK treatments lessened significantly the oxidative stress indicators in plant, while improved wheat growth parameters. The treatments of Biochar +NPK had the most profound effects for plant fresh weight and length, antioxidant constituents while recorded the least concentrations of Cr in both roots and shoot.
Conclusions Combined poultry litter biochar and NPK inorganic are potential improving biochemical attributes responsible of coping Cr stress.