02497naa a2200301 a 450000100080000000500110000800800410001902400360006010000210009624501080011726000090022550000950023452015340032965000120186365000160187565000230189165000130191465000180192765300290194565300320197465300270200665300310203365300160206465300170208070000180209770000170211577300630213210601332019-09-03       2019    bl uuuu     u00u1 u    #d7 a10.2134/agronj2018.03.01862DOI1 aSCHENEITER, J.O.  aUnder sressful conditions, high cattle density maintains white clover abundance.h[electronic resource]  c2019  aArticle history: Received: Mar 19, 2018//Accepted: Nov 25, 2018//Published: March 8, 2019.  aAbstract: The aim of the present study was to evaluate the abundance and dynamics of white clover (WC) (Trifolium repens L.) under cattle grazing, in a stressful environment. To this end, we performed a 5-yr experiment in Buenos Aires province, Argentina, where treatments were low and high forage offers (LFO and HFO) of a tall fescue (TF) [Lolium arundinaceum Schreb. (Darbysh.)]?WC mixture and two sites regarding the initial existence of WC in the pasture (with and without white clover, WC+ and WC?). Climatic conditions determined periods of deficiency or abundance of plant available water in the topsoil, which interacted with the grazing management, leading to either the absence or richness of WC in the pasture. Before a drought, the basal cover of WC was 31.0 and 11.2% with LFO and HFO treatments, respectively (P < 0.001); whereas, during recovery after drought, the corresponding values were 44.0 and 2.7% (P < 0.001), respectively. Re-establishment of WC at the pasture level was poorly related to the pre-drought spatial distribution. At the beginning of the experiment, the TF tiller density was greater in WC? sites; whereas, at the end of the experiment, the opposite was observed. The N derived from biological fixation was 85.5% and differences among treatments were of small magnitude. We concluded that, at the pasture level, the abundance of WC in an environment with hot and often dry summers is favored when the competition by TF is controlled and the availability of water in the soil is not limiting.  aFESTUCA  aLEGUMINOSAS  aMANEJO DE PASTOREO  aPASTURAS  aTREBOL BLANCO  aABUNDANCIA TREBOL BLANCO  aDINÁMICA DE TRÉBOL BLANCO  aHIGH FORAGE OFER (HFO)  aLOLIUM ARUNDINACEUM SCHREB  aTALL FESCUE  aWHITE CLOVER1 aBERTÍN, O.D.1 aLATTANZI, F.  tAgronomy Journal, 2019gv. 111, no. 3, p. 1198-1207, 2019.