Effects of plant species on CH4 and N2O fluxes from a volcanic grassland soil in nasu, Japan
2005
Mori, A. (National Inst. of Livestock and Grassland Science, Tsukuba, Ibaraki (Japan)) | Hojito, M. | Kondo, H. | Matsunami, H. | Scholefield, D.
To investigate the effects of plant species in grassland on methane (CH4) and nitrous oxide (N2O) fluxes from soil, fluxes from an orchardgrass (Dactylis glomerata L.) grassland, white clover (Trifolium repens L.) grassland and orchardgrass/white clover mixed grassland were measured weekly from April 2001 to March 2002 using a vented closed chamber method. Related environmental parameters (soil inorganic N content, soil pH (H2O) value, soil moisture content, soil temperature, grass yield, and the number of soil microorganisms) were also regularly monitored. On an annual basis, CH4 consumption in the soil of the orchardgrass grassland, white clover grassland and orchardgrass/white clover mixed grassland was 1.8, 2.4, and 1.8 kg C ha sup(-1) year sub(-1), respectively. The soil bulk density of the white clover grassland was lower than that of the other grasslands. Fluxes of CH4 were positively correlated with the soil moisture content. White clover increased the CH4 consumption by improving soil aeration. Nitrogen supply to the soil by white clover did not decrease the CH4 consumption In the soil of our grasslands. On the other hand, annual N2O emissions from the orchardgrass grassland, white clover grassland, and orchardgrass/white clover mixed grassland were 0.39, 1.59, and 0.67 kg N ha sup(-1) year sup(-1), respectively. Fluxes of N2O were correlated with the NO3- content in soil and soil temperature. White clover increased the N2O emissions by increasing the inorganic N content derived from degrading white clover in soil in summer.
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