Nitrogen And Water Regime Effects On Corn Yields Determined By N-15 Methodology

Abstract

Main objective of the research on soil and fertilizer N is to maximize the efficiency of N use in crop production. Increase of N use efficiency will increase the value of N as a crop production factor, increase farmer's profits and minimize any adverse effects on the environment that result from inefficient N use. Increase use of N fertilizer may result in large input of N fertilizer to soil from year to year and a corresponding increase in soil N may occur in well aerated fine textured soils (Gass, et.al., 1971. Herron, et. al., 1971). This residual N, while beneficial as a plant nutrient reservour, also may represent a potential loss and health hazard if it leaches beyond the root zone and pollutes ground water when heavy irrigation is done. Little attention has been paid in Cukurova Region (southern part of Turkey) to the possible leaching aspects of N fertilizer, although heavy irrigation and N fertilization practices are being performed by the farmers. Therefore, it is necessary to investigate the factors effecting the efficiency of applied N fertilizer. Isotopically labelled fertilizers provide a unique and valuable tool for this kind of investigation (Paltineanu,et.al.,1980). This investigation was carried out to determine the relationship between corn yields, fertilizer N leaching, fertilizer N application times, methods and applied water regimes using ¹⁵N labelled fertilizer.