TITLE:
Effects of Combined Application of Inorganic Fertilizer and Organic Manures on Nitrogen Use and Recovery Efficiencies of Hybrid Rice (Palethwe-1)
AUTHORS:
Kyi Moe, Kumudra Win Mg, Kyaw Kyaw Win, Takeo Yamakawa
KEYWORDS:
Nitrogen Uptake, Nitrogen Use Efficiency, Nitrogen Recovery Efficiency, Agronomic Nitrogen Use Efficiency, Hybrid Rice
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.5,
April
21,
2017
ABSTRACT: We
conducted two field experiments to investigate combined effects of organic and
inorganic fertilizers on nitrogen use and recovery efficiencies of hybrid rice
(Palethwe-1) during dry and wet seasons, 2015. Four levels of inorganic
fertilizer (0%, 50%, 75%, and 100% NPK), based on recommended rates of 150 kg N ha-1, 70 kg P2O5 ha-1, and
120 kg K2O ha-1, were used with cow manure, poultry manure, and vermicompost (5 t·ha-1each) in a split-plot design with three replicates. In both seasons, with
50% NPK, the N uptake level achieved with poultry manure was similar to that obtained
with 75% and 100% NPK. The greatest N use, internal, agronomic N use, and
recovery efficiencies were obtained with 50% NPK + poultry manure, but were similar to those obtained
from cow manure and vermicompost subplots. As the amount of applied N from
organic and inorganic fertilizer increased, the N use efficiency and related
parameters decreased, due to similar yields among plots with different NPK
application levels. Poultry manure resulted in the highest significant
correlations between applied N and N accumulation, followed by cow manure and
vermicompost, in both seasons. Neither chemical fertilizer nor organic manure
alone led to optimum N use and N recovery efficiencies. The combination of 50%
inorganic fertilizer (75 kg N ha-1) and poultry manure (5 t·ha-1) enhanced the N uptake, the N use and recovery efficiencies of hybrid
rice. Cow manure (5 t·ha-1) in combination with 75% inorganic fertilizer (112.5 kg N ha-1) was an adequate substitute for reduced chemical fertilizer usage.
Therefore, this study highlighted combined application of inorganic fertilizers
and organic manures had the benefits not only in reducing the need for chemical
fertilizers but also in improving N uptake by hybrid rice (Palethwe-1) leading
to the better environment.