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Need-Based Nitrogen Management Using Leaf Color Chart in wet Direct-Seeded Rice in Northwestern India.

Authors :
Bijay-Singh
Gupta, R. K.
Yadvinder-Singh
Gupta, S. K.
Singh, Jagmohan
Bains, J. S.
Vashishta, Monika
Source :
Journal of New Seeds; 2006, Vol. 8 Issue 1, p35-47, 13p, 4 Charts
Publication Year :
2006

Abstract

Wet direct-seeded rice (Oryza sativa L.) (DSR) is an attractive alternative to transplanted rice, as it saves the drudgery of raising seedlings and transplanting, reducing labor and cost of cultivation. As DSR stays in the field for a longer duration than transplanted rice and water management differs considerably, particularly during early growth stages, need-based fertilizer N management in DSR using chlorophyll meter (SPAD meter) and leaf color chart (LCC) was investigated vis-à-vis fixed-time N application schedules. Applying fertilizer N following sufficiency index approach that ensures maintaining intensity of the color of the uppermost fully opened rice leaves at 90% or more of the intensity of the color of the leaves in the over-fertilizer reference plot, resulted in application of only 70 kg N ha<superscript>-1</superscript>. It resulted in grain yield of rice equivalent to that produced by applying 80 or 120 kg N ha<superscript>-1</superscript> in four equal split doses. Since rice farmers may not be able to follow the sufficiency-index approach, two experiments were conducted to find the critical color shade on the LCC to guide need-based fertilizer N application to DSR. Application of 30 kg N ha<superscript>-1</superscript> whenever intensity of the color of the uppermost fully opened leaf of the rice plant was less than LCC shade 3 (LCC3) resulted in higher yields than application of 80 and 120 kg N ha<superscript>-1</superscript> in four equal split doses at fixed times. As higher fertilizer N-use efficiency was recorded with need-based N management using LCC3 rather than LCC4 as critical color shade, this study suggested that to obtain high yields and N-use efficiency, fertilizer N application should be guided by LCC3. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
1522886X
Volume :
8
Issue :
1
Database :
Complementary Index
Journal :
Journal of New Seeds
Publication Type :
Academic Journal
Accession number :
23914520
Full Text :
https://doi.org/10.1300/J153v08n01_03