ISSN:
1573-5036
Keywords:
Acetylene reduction
;
Associative N2-fixation
;
Cynodon dactylon
;
Enterobacter cloacae Inoculation
;
Klebsiella pneumoniae
;
Panicum coloratum
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02375062
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