Optimizing grain yields reduces CH4 emissions from rice paddy fields.
Microbial production in anoxic wetland rice soils is a major source of atmospheric CH4 the most important non-CO2 greenhouse gas. Much higher CH4 emissions from well managed irrigated rice fields in the wet than in the dry season could not be explained by seasonal differences in temperature. We hypothesized that high CH4 emissions in the wet season are caused by low grain to biomass ratios. In a screenhouse experiment, removing spikelets to reduce the plants' capacity to store photosynthetically fixed C in grains increased CH4 emissions, presumably via extra C inputs to the soil. Unfavorable conditions for spikelet formation in the wet season may similarly explain high methane emissions. The observed relationship between reduced grain filling and CH4 emission provides opportunities to mitigate CH4 emissions by optimizing rice productivity.
Laboratory of Soil Science and Geology, Wageningen University, P.O. Box 37, 6700 AA Wageningen, The Netherlands.
H A C
HA
Denier Van Der Gon
M J
MJ
Kropff
N
N
Van Breemen
R
R
Wassmann
R S
RS
Lantin
E
E
Aduna
T M
TM
Corton
H H
HH
Van Laar
D000383:Agriculture; D000393:Air Pollutants / Q000378:metabolism; D001272:Atmosphere / Q000032:analysis; D002244:Carbon / Q000378:metabolism; D017752:Greenhouse Effect; D008697:Methane / Q000378:metabolism*; D008954:Models, Biological; D009584:Nitrogen / Q000378:metabolism; D012275:Oryza / Q000254:growth & development* / Q000378:metabolism* / Q000382:microbiology; D010788:Photosynthesis; D012621:Seasons
D000393:Air Pollutants; D002244:Carbon; D009584:Nitrogen; D008697:Methane