Citation Context

...otential for groundwater contamination. This concern has pressured farmers to use N more efficiently. Nitrogen use efficiency (NUE) is defined as grain production per unit of N available in the soil (=-=Moll et al., 1982-=-; Van Sanford and Mackown, 1986). Nitrogen uptake and partitioning between straw and grain are the two major components of N economy in plants (Desai and Bhatia, 1978). Partitioning N between grain an...

Citation Context

...ld of such genotypes. Plant shoots may be a significant source of N loss in crops. Volatile N has been found to be released from plant tissue with NH3 being the prevalent form of postanthesis N loss (=-=Harper et al., 1987-=-). Francis et al. ( 1993) found maximum net N accumulation in corn to occur during early reproductive development (Rl - R3) followed by a subsequent decline. They found plant N loss could account for ...

Citation Context

...n an automated grinding unit to obtain finely ground forage, grain, and straw subsamples. Total N was determined on forage, grain and straw samples using a Carlo-Erba NA 1500 dry combustion analyzer (=-=Schepers et al., 1989-=-). Nitrogen use efficiency was analyzed according to an expanded model of Moll et al. (1982). Nitrogen use efficiency for grain yield was partitioned into various components as follows: Gw/Ns = grain ...

Citation Context

...that can absorb N more efficiently from the soil and effectively partition absorbed N to the grain. Such cultivars could minimize loss of N from the soil and make more economic use of the absorbed N (=-=Dhugga and Waines, 1989-=-). Because crop fertilizer recovery seldom exceeds 50%, the potential for increasing NUE has stimulated new research. It is the unaccounted portion in the crop that is currently being addressed in res...

Citation Context

...id not identify the exact date (physiological stage) where N accumulated in wheat was at a maximum. Based on the literature cited, flowering was the best estimate for maximum N accumulation in wheat (=-=Daigger et al., 1976-=-). In addition, plant N loss as estimated here assumes that no added soil N uptake took place beyond flowering. This is somewhat unrealistic since we know that the wheat plant continues to assimilate ...

Citation Context

...igger et al , 1976). Failure to include direct plant N losses when calculating an N budget can lead to overestimation of losses from the soil by denitrification, leaching, and ammonia volatilization (=-=Francis et al., 1993-=-). Proper accounting for volatile plant N losses may play an important role in developing cropping systems that have improved N fertilizer use efficiencies and reduced environmental impact. D o w n lo...

Citation Context

...d N was lost to leaching and denitrification. INTRODUCTION Worldwide interest associated with increasing cereal grain protein has focused added attention on improving the utilization of N in cereals (=-=Desai and Bhatia, 1978-=-). The effectiveness with which N is used by wheat and other cereals has become increasingly important because of increased costs associated with the manufacture and distribution of N fertilizer. Incr...