Distribution of Nitrate-N and Nitrogen Uptake by Rainfed Maize as Affected by Methods of Application of Urea

Distribution of nitrate-N in soil profile up to 180 cm and N uptake as affected by methods of urea application were studied in field experiments conducted with rainfed maize on alluvial-sandy loam and loamy sand soils in Punjab. The distribution and the amount of nitrate in the profile were greatly influenced by the method of N application. The differences were marked initially and these narrowed down with the age of the crop. The crop absorbed more of N when applied by drilling or in two splits in loamy sand whereas methods of application did not influence the uptake in sandy loam soil. A simultaneous consideration of the amount of unused nitrate-N at the harvest of the crop and grain yield, however, indicated superiority of the two split application in loamy sand and drill application on sandy loam soil in increasing the fertilizer use efficiency by enhancing N uptake and reducing nitrate leaching losses.