EFFECTS OF VARIOUS BIOCHARS ON SEED GERMINATION AND CARBON MINERALIZATION IN AN ALKALINE SOIL

Use of biochar (BC) as soil amendment improves soil physicochemical properties, carbon sequestration and plant growth. However, prior to use as amendment, BC must be evaluated for its potential effects on soil and plants. In this study, various wastes (cotton-sticks, vegetable-market waste, poultry-manure, rice-straw, Eucalyptus camaldulensis –leaves, Neem (Azadirakta indica) –leaves, citrus-leaves, wheat straw and house-hold waste) were converted into BCs using pyrolysis (350 - 450 °C). Later, the prepared BCs were analyzed for pH, EC, moisture, ash and volatile matter, and nutrients such as carbon, nitrogen, phosphorus, and potassium using recommended methodologies. In first experiment, BCs were applied to an alkaline soil at rate of 1 % and maize seeds were grown. In this study effect of BCs on germination parameters, seedlings growth attributes, soil pH and EC were investigated. In second experiment, the C mineralization of various BCs in alkaline soil was investigated. The results show significant effect of vegetable waste biochar, and eucalyptus-leaves biochar on seedlings dry matter, shoot lengths, and root lengths. Regarding germination, none of the BCs caused detrimental effect. The results of C mineralization study show no significant differences between control treatment and BCs for cumulative CO2 release. It is concluded that biochars produced from above described feedstock have no negative effect on soil and plant system, rather can improve carbon levels in alkaline soils.