Effect of Biochars Produced at Different Pyrolysis Temperatures on Ammonium (NH4+) and Nitrate (NO3-) Leaching: Column Experiment

Abstract

Nitrogen (N) leaching from agricultural soils is a global problem with negative effects on both human health and the environment. Efforts should be made to increase the efficiency of use of plant nutrients and minimize N losses from terrestrial ecosystems to aquatic ecosystems. In this study, the effects of different doses (%0, %1 and %2) of biochar obtained from corn cob and rice husk biomass, which are agricultural production residues, at three different temperatures (300, 400 and 500℃), on ammonium (NH4+) and nitrate (NO3-) leaching in a coarse-textured soil were investigated. PE columns with a diameter of 70 mm and a height of 20 cm were used in the study, which was carried out in three replications according to the randomized plots trial design. Total nitrogen (27 kg N da-1) and water amounts (969 mm) used for 6 tons da-1 yield of sugar beet were applied. Total water was given to each column in equal volume using drip adjustment sets at one-week intervals, simulating 6 irrigation periods, and the leaked water was collected in each irrigation period and NO3- and NH4+ concentrations were determined. Applications of 1 and 2 doses of corn and rice biochars obtained at three different pyrolysis temperatures caused a significant decrease in NH4+ concentrations leaching from the column. Similarly, biochar applications (especially 2% dose) caused a significant decrease in NO3- concentrations leaching from the column. While the total NO3- concentration leaching from the control columns was 149,23 mg kg-1, 2% dose of rice husk biochars at 300, 400 and 500℃ temperature applications caused a decrease in the total NO3- concentrations washed from the column by 51%, 55% and 51%, respectively. The results revealed that biochar applications significantly reduced nitrogen leaching from the soil.