Nitrogen dynamics in lowland rice as affected by crop establishment and nitrogen manangement

Issue Date

9-2007

Abstract

Information on the dynamics of nitrogen as influenced by crop establishment method and N management strategy is meager, but such information is necessary in optimizing nitrogen input for lowland rice (Oryza sativa L.). A field experiment was conducted at the experimental farm of the International Rice Research Institute (IRRI), Philippines, during the wet and dry seasons of 2003 and 2004 to evaluate the effects of crop establishment and nitrogen management strategies for lowland rice on the dynamics of mineral N. The experiment was laid out in a split-plot design with four crop establishment methods as main plots and two N management techniques as subplots with three replications. Zero-N fertilizer (N-omission) micro-plots were embedded in each plot. Crop establishment method did not significantly influence uptake of indigenous mineral N during the wet (44-55 kg ha-1) and dry (43-50 kg ha -1) seasons. Apparently, NH4+-N and NO 3--N accumulated in the top 20-cm layer of the soil during the wet season, resulting in relatively high initial N during the dry season. Crop establishment and N management strategies did not influence crop removal of N during a one-year period. Actual N balance across crop establishment methods during the one-year period ranged from 10 to 16 kg ha-1, whereas the apparent N balance ranged from 45 to 99 kg ha-1. A fertilizer recommendation should be developed based on the actual N balance along with the assessment of crop N requirement for a given yield potential. Copyright © by The Haworth Press, Inc. All rights reserved.

Source or Periodical Title

Journal of Crop Improvement

ISSN

15427528

Volume

20

Issue

2

Page

89-105

Document Type

Article

Language

English

Subject

Direct seeding, Nitrogen balance, SPAD and standard N management, Transplanting

Identifier

https://doi.org/10.1300/J411v20n01_05

Digital Copy

YES

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