Greenhouse gas emissions in irrigated paddy rice as influenced by crop management practices and nitrogen fertilization rates in eastern Tanzania
Loading...
Date
2022
Journal Title
Journal ISSN
Volume Title
Publisher
Frontiers
Abstract
In rice production greenhouse gas emission (GHG) reduction is an important
task for many countries, Tanzania included. Of global agricultural GHG emitted
from rice fields, about 30 and 11% are represented by CH4 and N2O,
respectively. For successful climate smart rice cultivation, rice management
practices, including nitrogen fertilization are two key crucial components
that need evaluation. The objective of this study was to evaluate the crop
management practices and N fertilization on yield and greenhouse gases
emission in paddy rice production, Experiments were designed in split-plot
randomized complete block and replicated three times. Two rice management
practices namely conventional practice (CP) and system of rice intensification
(SRI) and six rates of nitrogen fertilizer (absolute control, 0, 60, 90,120 and
150 kg N ha−1) were applied in two consecutive seasons. The Source-selective
and Emission-adjusted GHG CalculaTOR for Cropland (SECTOR) was used
to calculate the GHG emission. Methane emission was in the range of
88.7–220.6 kg ha−1season−1, where higher emission was recorded in CP
treatments (ABC, CP 0 and CP 120N) compared to SRI treatments. SRI
reduced methane and carbon dioxide emission by 59.8% and 20.1% over CP,
respectively. Seasonal nitrous oxide emissions was in the range of no detected
amount to 0.0002 kgN2O ha−1 where SRI treatments recorded up to 0.0002
kgN2O ha−1 emissions while in CP treatment no amount of N2O was detected.
The interaction of system of rice intensification and 90 kg N ha−1 (SRI90N)
treatment recorded higher grains yield (8.1, 7.7 t ha−1) with low seasonal global
warming potential (GWP) (3,478 and 3,517 kg CO2e ha−1) and low greenhouse gas intensity (0.42, 0.45 kg CO2e per kg paddy) compared to other treatments
in wet and dry season, respectively. Therefore, SRI with 90 kg N was the
treatment with mitigation potential and reduced GWP without compromising
rice yield
Description
Journal Article
Keywords
Greenhouse gas emission, System of rice intensification, Rice, Conventional practice, Management practices, Global warming potential, Climate change