Evaluating rate, timing and method of N application using tracer technique [Egypt]
1986
Homissa, M.R. | Mahrous, F. | Nour, M. | Ezzat, A. (National Rice Research Inst., Giza (Egypt). Agricultural Research Centre)
Yield and conventional and isotopic analyses of plant material indicate that grain and straw yields, as well as total N uptake, increased with rate of N application up to 108 kg/ha. All timing and methods of N application-banding in dry soil, point placement 10 cm deep in soil, topdressing 2/3 at 35 d after transplanting (DT) + 1/3 of at panicle initiation (PI) and banding 2/3 in dry soil + 1/3 at PI-gave roughly comparable results. However, point placement was superior. Yields with N broadcast in water before leveling and topdressing 2/3 15 DT and 1/3 at PI were lower. The % N derived from fertilizer increased as the rate of application increased up to 108 kg N/ha. However, the difference between 72 and 108 kg N/ha was insignificant. Point placement treatment was best, broadcasting N in water before leveling was least effective. Amount of fertilizer N taken up by the pla0858nt showed similar patterns. Recovery of fertilizer N ranged from 9.6 to 39.4%. Values for point placement and topdressing 2/3 at 35 DT and 1/3 at PI were highest, those for the traditional treatment of N broadcast in water before leveling were low
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