02324nam a2200289 a 450000100080000000500110000800800410001910000130006024501500007326000430022330000100026650000190027652015440029565000230183965000150186265000140187765000160189165000240190765000130193165000110194465000160195565000150197165300110198665300120199765300100200965300150201913231752014-01-15       1979    bl uuuu  m   00u1 u    #d1 aPOTT, A.  aEffects of sheep grazing and treading, and of shading on the growth and population dynamics of Lotonomis bainesii grown with Digitaria decumbens.  aAustralia: University Queenslandc1979  a241p.  aTese Mestrado.  aThe productivity and persistence of Lotononis bainesii cv. Miles grown with Digitaria decumbens cv. pangola was studied in two field experiments (exp.-1 grazing intensity, and exp.-2 treading), conducted at the University of Queensland Research Station at Mt. Cotton, on a red-yellow podzolic soil. A glasshouse experiment (exp.-3 shading) at St. Lucia contrasted the shade tolerance of the two species. Exp.-1 lasted two years, and comprised 4 stocking rates (7, 14, 21 and 28 sheep ha-1); six replicates were grazed in rotation (3 days on, 15 days off). Pasture dry matter yields and botanical composition were assessed three-monthly, and Lotononis demography was monitored by tagging individual plants in permanent quadrats, core sampling for stolon nodal root population and soil seed reserves (flotation recovery); in addition, soil bulk density was estimated. Lotononis did not persist under grazing regardless of stockinh rate. It behaved as a short-lived plant, predominantly annual, with some (insufficient) vegetative perennation (stolon rooted units) under heavy grazing. Soil seed reserves were 550 seeds m-2 (1.6 kg ha -1) under 21-28 sheep ha-1, compared to 4500 seeds m-2 (13 kg ha-1) under lenient grazing. Lotononis failed to regenerate under Pangola shading/or inopportune high grazing pressure, and there was no ideal level of stocking rate. Soil bulk density (top 7 cm) increased from 1.2 g cm-3 under 7 sheep ha-1 to 1.4 g cm-2 under 21 sheep ha-1. Exp.-2 was carried out on a Lotononis/Pangola sward using Edmond's...  aLotononis bainesii  apopulation  aAgronomia  aCrescimento  aDigitaria Decumbens  aPastagem  aPlanta  aPopulação  aProdução  aGrowth  aPasture  aPlant  aProduction