Summary
Previous investigations indicated some forage grass roots in Texas are heavily colonized with N2-fixing bacteria. The most numerous N2-fixing bacteria were in the genera Klebsiella and Enterobacter. In the present investigation inoculation experiments were conducted using 18 isolates of these bacteria to determine if a N2-fixing association could be established between the bacteria and the grassesCynodon dactylon andPanicum coloratum. Plants were grown in soil for approximately 5 months in a greenhouse and were measured periodically for dry matter, nitrogen accumulation, and acetylene reduction activity. Results of the investigation indicated that 25% of the plant-soil systems were active in acetylene reduction and the activity was high enough to indicate agronomically significant quantities of N2 were being fixed (>8kg N ha−1). However, plant systems extrapolated to fix>8 kg N ha−1 contained less nitrogen and accumulated less dry matter than plants less active in acetylene reduction. Inocula could not be re-isolated from healthy grass roots indicating that the N2-fixing activity may have not have been closely assiciated with plant roots. Future research is needed to determine factors limiting colonization of grass roots.
References
Baltensperger A Aet al. 1978 Crop Sci. 18, 1043–1045.
Barber L Eet al. 1976 Appl. Environ. Microbiol. 32, 108–113.
Bouton J Het al. 1979 Crop Sci. 19, 12–16.
Bouton J H and Zuberer D A 1979 Plant and Soil 52, 585–590.
Brown M E 1976 J. Appl. Bacteriol. 40, 341–348.
Edwards P R and Ewing W H 1972 Identification of Enterobacteriaceae, 3rd ed. Burgess Publishing Co., Minneapolis, Minn.
Hino S and Wilson P W 1958 J. Bacteriol. 75, 403–408.
Legg J Oet al. 1971 Soil Sci. Soc. Am. Proc. 35, 273–276.
Smith A M 1976 Soil Biol. Biochem. 8, 293–298.
Smith R Let al. 1976 Science 193, 1003–1005.
Stanford Get al. 1973 J. Assoc. Off. Anal. Chem. 56, 1365–1368.
Tjepkema J D and Evans H J 1976 Soil Biol. Biochem. 8, 505–509.
Tjepkema J D and Burris R H 1976 Plant and Soil 45, 81–94.
Weaver R Wet al. 1980 Agron. J. 72, 965–968.
Wood L Vet al. 1980 Can. J. Microbiol. 27, 52–56.
Wright S F and Weaver R W 1981 Soil Biol. Biochem. 13, 225–226.
Wright S F and Weaver R W 1981 Appl. Environ. Microbiol. 42, 97–101.
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Wright, S.F., Weaver, R.W. Inoculation of forage grasses with N2-fixing Enterobacteriaceae. Plant Soil 65, 415–419 (1982). https://doi.org/10.1007/BF02375062
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DOI: https://doi.org/10.1007/BF02375062