FATE OF 15N UREA AS PLANT AVAILABLE FORM WITH AND WITHOUT BIOCHAR IN THE SOIL PROFILE (0-30CM)
Abstract
Urea fertilizer is broadly used in agriculture sector because of higher water solubility and quick release into plant available nitrogen (N) but causes more N losses as leaching and gaseous emissions. However, different types of amendments have been applied to overcome this problem, but the byproduct of biomasses pyrolysis called biochar is getting fame because of its environmental benefits. This study is based upon the comparative analysis of urea fertilizer composed of stable isotopic nitrogen (15N) in lysimeters (30cm diameter and 35cm height) with (BT) and without biochar (CK) for Brassica Camprestis Var. Chinensis plantation in two successive cropping seasons (April to July and Sept. to December) in Beijing, China. The comparative analysis showed that plant yield was non-significant, but BT accumulative (first and second seasons) N plant uptake increased 10.62%, decreased N leaching 10.7%, retained more N in soil 11.37% and reduction in unaccounted losses 11.8% as compared to CK. Moreover, soil in BT showed non-significant increase is soil pH and decrease in bulk density but significant increase in EC after second season. Thus, biochar amendment in agricultural soil reduces the N losses and increases residence time for urea in soil.
