02156naa a2200289 a 450000100080000000500110000800800410001910000160006024501330007626000090020952013380021865000130155665000160156965000150158565000160160065000090161665300220162565300230164765300200167065300150169065300250170565300130173065300230174370000160176670000220178277300620180413700821998-09-30       1985    bl ---       0--  u    #d1 aLYND, J. Q.  aMycorrhiza-soil fertility effects on regrowth nodulation and nitrogenase activity of siratro(Macroptilium atropurpurem(DC) Urb.)  c1985  aSiratro (macroptilium atropurpurem (DC) Urb.) is a vigorous perennial forage legume with good potential for improving pastures in the extensive neotropical regions of the world. It is well  adapted to a wide range of soil and climatic conditions. The objective of these studies was to determine effects os glomus fasciculatum colonization, rigorous defoliation, and soil fertility treatments to a Psammentic oaleustalf(Eufaula) soil on growth regrowth, nodulation, and nitrogenase activity (C2H2 red.) of Siratro inoculated with Rhizobium leguminosarum Frank. Top growth increased significantly with soil K and P amendment and with mycorrhiza colonization. Nodulation and nitrogenase activity were correlated with highly significant increase from G. fasciculatum, P treatments and K additions to 300 mg K kg-1 soil. Growth and penducles of nonclipped plants increased about 4 fold from 90 to 225 day age with mature seed yield increasing about 10 fold; nodule mass and nitrogenase activity levels approximately doubled. Regrowth response of plants defoliated at 45 day intervals, following their initial 90 day age, was somewhat constat between clipings for magnitude of regrowth 12.3-13.8g, development in number of peduncles 4.0-6.8, seed yield 1.4-2.6g, nodulation 2.9-3.7g, and nitrogenase activity 73.9-95.8 mol. C2h4g-1 nodule.  anitrogen  aFertilidade  aLeguminosa  aNitrogênio  aSolo  aBacteria fixadora  aFixacao simbiotica  aFixing bacteria  aForrageira  aNitrogenase activity  aRhizobia  aSimbiotic fixation1 aTYRL, R. J.1 aPURCINO, A. A. C.  tJournal of Plant Nutritiongv.8, n.11, p.1047-1059, 1985.