Organic Amendments Enhanced Phytoremediation, Physio-Chemical Functions, Growth and Productivity of Zea mays L. in Diesel-Contaminated Soil

The association of organic amendments like biochar (BC), compost (CM), and manure (MN) to assist phytoremediation of artificially diesel oil-contaminated soil was investigated in this study. Maize plants were exposed to amount of hydrocarbon (diesel oil 30,000 mg kg- 1 soil), biochar (50 gram pot- 1), compost (200 gram pot- 1), and manure (200 gram pot- 1) separately and in combination, to investigate the effects on growth, physiological response of the plant in artificially diesel oil contaminated soil. The combined application of BC, CM and MN associated with maize plants had significant dispersion in hydrocarbon parameters (total petroleum hydrocarbons (TPHs) 84%, n alkanes 52% and polycyclic-aromatic hydrocarbon (PAHs) 32% as compared to artificial contaminated soil (control), similarly, combined BC, CM and MN treatment improved the soil physicochemical properties (electrical conductivity 40.3%, total soil nitrogen (N) 233.3%, available phosphorus (P) 41.7% soil, available potassium (K) 70.5% soil and total soil organic matter (TSOM) 173.8% as compared to control. The application of combined BC, CM and MN enhanced chlorophyll a (52.6%), chlorophyll b (58.3%), total chlorophyll (54.2%), photosynthetic rate (53.2%), transpiration rate (66.4%), and substomatal CO2 (28.1%), however, for highest increase in stomatal conductance (45.2) when BC and MN was applied. The highest increase of plant parameters (germination-90%, fresh shoot biomass-48.67 gram pot- 1, dry shoot biomass-10.00 gram pot- 1, fresh root biomass-10.67 gram pot- 1, dry root biomass-2.24 gram pot- 1 were noted when combined application of BC, CM and MN was applied. Combined BC, CM and MN have great application prospects in improving soil health, plant photosynthesis and yield of maize under hydrocarbons contaminated soil.