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In the context of sustainable soil-quality management and mitigating global warming, the impacts of incorporating raw or field-burned adzuki bean (Vigna angularis(Willd.) Ohwi & Ohashi) and wheat (Triticum aestivumL.) straw residues on carbon dioxide (CO2) and nitrous oxide (N2O) emission rates from soil were assessed in an Andosol field in northern Japan. Losses of carbon (C) and nitrogen (N) in residue biomass during field burning were much greater from adzuki bean residue (98.6% of C and 98.1% of N) than from wheat straw (85.3% and 75.3%, respectively). Although we noted considerable inputs of carbon (499 ± 119 kg C ha–1) and nitrogen (5.97 ± 0.76 kg N ha–1) from burned wheat straw into the soil, neither CO2nor N2O emission rates from soil (over 210 d) increased significantly after the incorporation of field-burned wheat straw. Thus, the field-burned wheat straw contained organic carbon fractions that were more resistant to decomposition in soil in comparison with the unburned wheat straw. Our results and previously reported rates of CO2, methane (CH4) and N2O emission during wheat straw burning showed that CO2-equivalent greenhouse gas emissions under raw residue incorporation were similar to or slightly higher than those under burned residue incorporation when emission rates were assessed during residue burning and after subsequent soil incorporation. [ABSTRACT FROM PUBLISHER]

The article presents a study on the estimation of the phylogenies of 129 NO3- reducing bacteria that were isolated from fields soils in Japan. The bacterial phylogeny was estimated with the use of microchip electrophoresis system which were then compared with the estimated phylogeny by carbon source utilization profiles and comparative analysis of 16S rDNA. Result suggests that various kinds of non-indigenous and non-bacillus bacteria were introduced from livestock feces.

In the context of their role in net global warming, CO2 emissions were calculated for fuel-consuming processes associated with arable land crop production in Hokkaido, northern Japan. Fuel-consuming processes included tractor-based field operations, transportation of products and materials and grain drying. In conventional tillage (CT) systems, total CO2 emissions from fuel consumption were 826.2, 605.4, 424.2 and 738.7 kg CO2 ha−1 for winter wheat (Triticum aestivum L.), sugar beet (Beta vulgaris L.), adzuki bean (Vigna angularis (Willd.) Ohwi and Ohashi) and potato (Solanum tuberosum L.) production, respectively. In winter wheat production, 55% of total CO2 emission were released from kerosene and electricity use for grain drying, the remainder from tractor-based field operations. In contrast, for sugar beet, adzuki bean and potato production, field operations were the main contributors to CO2 emissions. Of the field operations, tillage and harvesting required the largest amounts of fuels. Under reduced tillage (RT) systems in which soil preparation in early spring was reduced and plowing after harvesting was omitted, 47.5 l ha−1 of diesel oil equivalent to 125.4 kg CO2 ha−1 could be saved, regardless of crop species. Consequently, total CO2 emissions could be reduced by 15–29%, respectively, in winter wheat and adzuki bean production. In the Tokachi region of Hokkaido, a primary arable crop production region in Japan, annual CO2 emissions under CT and RT for the four crops produced were estimated at 82.7 Gg CO2 per year and 67.4 Gg CO2 per year, respectively. Besides reduced fuel costs, the use of RT production systems could significantly reduce the large quantities of CO2 released as a result of arable land crop production in northern Japan. [Copyright &y& Elsevier]

Phylogenetic estimation method without determination of DNA sequence was developed. By this method, fragment length polymorphism separately digested with multiple restriction enzymes was measured using microchip electrophoresis and affiliated with those calculated from corresponding DNA sequence in the theoretical database. The phylogenies of 129 NO(3)(-) reducing bacteria newly isolated from field soils were estimated by this method, and were compared to those by carbon source utilization profiles and by comparative sequence analysis of 16S rDNA. Various bacteria such as Micrococcus sp. (one isolate), Acidovorax delofieldii (one isolate), Cupriavidus necator (one isolate), Burkholderia sp., (seven isolates), Commamonas acidovorans (two isolates), Herbaspirillum seropedicae (two isolates), Ralstonia sp. (six isolates), Pseudomonas spp. (14 isolates), and Acinetobacter spp. (one isolate), were affiliated as similar to those by sequence analysis of 16S rDNA, while exact affiliation of genus was difficult for those belonging to Enterobacteriaceae.