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To compare the CH4 oxidation potential among diferent land uses and seasons,and to observe its response to monsoon precipitation pattern and carbon and nitrogen parameters,a one-year study was conducted for diferent land uses (vegetable field,tilled and non-tilled orchard,upland crops and pine forest) in central subtropical China.Results showed significant diferences in CH4 oxidation potential among diferent land uses(ranging from 3.08 to 0.36 kg CH4 ha-1 year-1).Upland with corn-peanut-sweet potato rotation showed the highest CH4 emission,while pine forest showed the highest CH4 oxidation potential among all land uses.Non-tilled citrus orchard (0.72±0.08 kg CH4 ha-1 year-1)absorbed two times more CH4 than tilled citrus orchard(0.38±0.06kg CH4 ha-1 year-1).Irrespective of diferent vegetation,inorganic N fertilizer application significantly influenced CH4 fluxes across the sites (R2=0.86,P=0.002).Water-filled pore space,soil microbial biomass carbon,and dissolved nitrogen showed significant efects across diferent land uses (31% to 38% of variability)in one linear regression model.However,their cumulative interaction was significant for pine forest only,which might be attributed to undisturbed microbial communities legitimately responding to other variables,leading to net CH4 oxidation in the soil.These results suggested that i)natural soil condition tended to create win-win situation for CH4 oxidation,and agricultural activities could disrupt the oxidation potentials of the soils;and ii)specific management practices including but not limiting to efficient fertilizer application and utilization,water use efciency,and less soil disruption might be required to increase the CH4 uptake from the soil.
To compare the CH4 oxidation potential among diferent land uses and seasons, and observe their response to monsoon precipitation pattern and carbon and nitrogen parameters, a one-year study was conducted for diferent land uses (vegetable field, tilled and non-tilled orchard, upland crops and pine forest) in central subtropical China. Results showed significant diferences in CH4 oxidation potential among diferent land uses (ranging from 3.08 to 0.36 kg CH4 ha-1 year-1) .Upland with corn-peanut-sweet potato rotation showed the highest CH4 emission, while pine forest showed the highest CH4 oxidation potential among all land uses. Non-tilled citrus orchard (0.72 ± 0.08 kg CH4 ha-1 year-1) absorbed two times more CH4 than tilled citrus orchard (0.38 ± 0.06 kg CH4 ha -1 year -1). Irrespective of diferent vegetation, inorganic N fertilizer application significantly influenced CH 4 fluxes across the sites (R2 = 0.86, P = 0.002). Water- filled pore space, soil microbial biomass carbon, signi ficant efects across diferent land uses (31% to 38% of variability) in one linear regression model. However, their cumulative interaction was significant for pine forest only, which might be attributed to undisturbed microbial bacteria legitimately responding to other variables, leading to net CH4 oxidation in the soil .sese results suggested that i) natural soil tended to create win-win situation for CH4 oxidation, and agricultural activities could disrupt the galvanic potentials of the soils; and ii) specific management practices including but not limiting to efficient fertilizer application and utilization, water use efciency, and less soil disruption might be required to increase the CH4 uptake from the soil.