Journal of Animal and Plant Sciences
J. Anim. Plant Sci. [ISSN 2071 - 7024]
Volume 6 (1): 589 - 596. Published February 25, 2010.
Effect of crop management practices on Nitrogen (N) availability and N use efficiency in direct wet-seeded rice
Y.O. Mnguu
*Institute of Rural Development Planning (IRDP), P.O. Box 138, Dodoma, Tanzania
Corresponding author email: ymnguu@yahoo.com
SUMMARY
The effect of crop management practices on nitrogen (N) availability and N use efficiency in lowland rice (Oryza sativa L.) was investigated at International Rice Research Institute (IRRI) and PhilRice (Muñoz, Nueva Ecija) in the Philippines. The experimental design was randomized complete block with four replications. The treatments were factorial combinations of crop and N fertilizer management practices. Four experiments with wet direct seeded rice were conducted during 2003 and 2004 dry seasons. The results indicated that indigenous N supply (INS) was not significantly different between methods of weed control. Weed control using rotary weeding significant increased extractable soil ammonium during 2004 dry season although N uptake at maturity was not significantly higher in these treatments at both sites. The agronomic efficiency of applied N (AEN) varied between sites, N and crop management practices. At IRRI, AEN in treatments with herbicide application was significantly higher than in rotary weeding. It was also revealed from the study that broadcast and hill sowing were equally effective in grain yield, although hill sowing offers more opportunity to reduce seed rate and flexibility for mechanical weed control.
Key words: -Direct Seeded Rice; Leaf Color Chart; N use efficiency; N availability
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