Technologies for utilizing biological nitrogen fixation in wetland rice: potentialities, current usage, and limiting factors

Seasonal Changes in N2 Fixation Activity and N Enrichment in Paddy Soils as Affected by Soil Management in the Northern Area of Japan

“…The value of 5.2 mg N g -1 cellulose consumed (or 4.5 mg N g -1 cellulose added) under dark conditions was comparable to the reported values of 2 to 7 mg N g -1 cellulose added 8 and 0.1 to 7.1 (2.4 on the average) mg N fixed g -1 C substrate (mainly straw) 9 . The highest N enrichment in the soil with and without amendment of cellulose was extrapolated to 1.6 to 2.0 g N m cropping season -1 in the tropical area and southern area of Japan 6,10 .…”

“…Submerged conditions in a rice paddy field provide suitable conditions for biological N 2 fixation (BNF) by both phototrophic and heterotrophic microorganisms 9 . Numerous semi-quantitative determinations of BNF attempted mainly in tropical Asia and southern Japan strongly indicated the significance of BNF for N enrichment in the paddy soil systems 6,9,10 . In the Tohoku region in northern Japan under cool temperate conditions, the significance of BNF was also implied by the increase in the amount of available and total N in the shallow soil layer during the cropping season 14,15 .…”

Community structure of bacteria and fungi responsible for rice straw decomposition in a paddy field estimated by PCR-RFLP analysis

“…Although the decomposition rate of rice straw (Shiga et al 1985;Watanabe et al 1993) and the effects of its application on methane flux (Schutz et al 1989;Yagi and Minami 1990;Watanabe et al 1998) and nitrogen cycling (e.g. nitrogen fixation, immobilization, and mineralization of nitrogen; Yoneyama et al 1977;Yoneyama and Yoshida 1977a, b, c;Roger and Watanabe 1986) in paddy fields have been studied in detail, the microorganisms responsible for rice straw decomposition in paddy fields have not been well documented. Kimura and Tun (1999) and Tun and Kimura (2000) conducted detailed observations of decomposing rice straw (sheaths and blades) in a flooded paddy field with a scanning electron microscope (SEM), and found that the leaf blades were decomposed mainly from inside the tissues and leaf sheaths both from the surface and from probably inside the tissues because microbial colonization of the blade surface was prevented by plate-like epicuticular wax.…”

Microscopic observation of the decomposition process of leaf blade of rice straw and colonizing microorganisms in a Japanese paddy field soil during the cultivation period of paddy rice

“…Although the decomposition of RS (Shiga et al 1985;Watanabe et al 1993) and effects of its application on methane flux (Schlitz et al 1989;Yagi and Minami 1990;Sass et al 1991;Cicerone et al 1992;Lindau and Bollich 1993;Neue et al 1994;Nouchi et al 1994;Watanabe et al 1998) and nitrogen cycling (e.g. nitrogen fixation, immobilization, and mineralization of nitrogen; Yoneyama et al 1977;Yoneyama and Yoshida 1977a, b, c;Yoshida and Rinaudo 1982;Roger and Watanabe 1986;Kundu and Ladha 1995) in paddy fields have been studied in detail, the decomposition process of RS and the microorganisms responsible for its decomposition in paddy fields have not been thoroughly documented.…”