TITLE:
Effects of N rates on N uptake and yield in erect panicle rice
AUTHORS:
Guiyun Song, Zhengjin Xu, Hengshan Yang
KEYWORDS:
N Use Efficiency Parameters; Erect Panicle Rice; Biomass
JOURNAL NAME:
Agricultural Sciences,
Vol.4 No.9,
August
28,
2013
ABSTRACT: The
field experiment was conducted in 2005 and 2006 at Northern Japonica Rice
Cultivation and Breeding Research Center, Shenyang Agricultural University,Shenyang, northeast China. Shennong 265 (typical erect panicle rice cultivar), and Liaojing 294
(traditional semi-erect panicle rice cultivar) were grown under different N
rates to assess N uptake and N use efficiency.
Nitrgen (N) uptake of two rice cultivars increased in their response to
N improvement. Grain N of Liaojing 294 predominantly came from root absorption
on low N treatments, while grain N of Shennong 265 mainly came from root
absorption and had less N re-transferring from vegetative organs under high N
rates. Shennong 265 produced less N uptake before heading and more N uptake
after heading than Liaojing 294. GY was highly related with N fertilizer rate
(r2 = 0.870** for Shennong 265, r2 = 0.613* for Liaojing 294). Shennong 265 was a N-unefficient genotype, since it produced
low yield at low N levels and responded well to N application. Liaojing 294 was
a N-efficient genotype producing high yield at both low and high N rates. NNG
and NFUE exhibited positive correlation with N application rates, but NUEPG
showed negative correlation with N application rates; GY as well as BIO and N
uses efficiency parameters (TN, NNG, NFUE) which were all positively correlate,
while the correlation between GY as well as BIO and the other N efficiency
indicators expressed negative correlation. The relationship between GY and TN
as well as BIO and TN was observed with significant difference (r2 = 0.824**, r2 = -0.858**).