02506naa a2200349 a 450000100080000000500110000800800410001910000180006024501940007826000090027252015210028165000180180265000180182065000120183865000150185065000170186565000100188265000150189265000200190765000150192765000140194265000150195665000140197165000160198565000130200165300160201465300160203065300120204670000200205870000160207877300620209412785822024-05-20       1989    bl uuuu     u00u1 u    #d1 aDAWSON, J. O.  aVariation with soil depth, topographic position and host species in the capacity of soils from an australian locale to nodulate Casuarina and Allocasuarina seedlings.h[electronic resource]  c1989  aSandy alluvial soils in a floodplain in Australian Capital Territory supporting a native stand of C. cunninghamiana produced about three times as many nodulated seedlings and more than twice as many nodules per nodulated seedling on roots of baited Casuarina spp. than did clay loam red earth soils from the adjacent valley slope. Moist and well-aerated subsurficial alluvial sands had the greatest nodulation capacity of all the soils sampled. For all topographic positions, soil samples from depths greater than 20 cm promoted 76% more nodulated Casuarina seedlings than samples from the surficial 20 cm. Seedlings of three provenances of C. cunninghamiana, together with seedlings of C. glauca, C. cristata and C. obesa developed significantly more nodules per pot and nodules per nodulated seedling in soils from this locale than seedlings of two Casuarina equisetifolia provenances. Seedlings of two provenances of Allocasuarina torulosa had fewer than 1% nodulated seedlings, significantly lower than that of Casuarina seedlings. A. torulosa provenances also had significantly fewer nodulated seedlings per pot and nodules per nodulated seedling than all Casuarina hosts except one poorly-nodulated provenance of C. equisetifolia. Nodulated seedlings of all Casuarina species had the capacity to fix atmospheric N2, as indicated by acetylene-reduction capability. The presence of yellow cladodes and low rates of acetylene reduction per plant for C. cristata suggest that this association was poorly effective.  aAllocasuarina  abiotechnology  aFrankia  anodulation  aroot nodules  aroots  asoil depth  asoil morphology  asoil types  asymbiosis  atopography  aCasuarina  aNitrogênio  aSimbiose  aActinorriza  aBroadleaves  aFixacao1 aKOWALSKI, D. G.1 aDART, P. J.  tPlant and Soil, The Haguegv. 118, n. 1-2, p. 1-12, 1989.