Soil Phosphorus Concentration under the Canopy of Perennial Grasses of Different

CARLOS A. BUSSO AND A.I. BOLLETTA

Communications in Soil Science and Plant Analysis

Taylor and Francis

Lugar: Athens, Georgia, USA; Año: 2007

In this field study, we determined the efíects of water stress, rainfed, or irrigatedIn this field study, we determined the efíects of water stress, rainfed, or irrigated 2 conditions on soil phosphorus concentration under the canopy of the native grasses of 3 semiarid Argentina (late seral Stipa clarazii Ball., and early serals 5. íenuis Phil. and S.Phil. and S.enuis Phil. and S. 4 gynerioides Willd. Ex Steud) at different developmental stages and sampling dates during 5 1996 and 1997. Plants grew in a uniform matrix such that each plant of S. clarazii and S. 6 tennis was surrounded by four plants of S. gynerioides. In September 1996, Bray and 6 tennis was surrounded by four plants of S. gynerioides. In September 1996, Bray and 6 tennis was surrounded by four plants of S. gynerioides. In September 1996, Bray and 7 Kurtz-extracted soil P concentrations were greater under plants of S. clarazii if water stress 8 was imposed during the vegetativo stage than under rainfed conditions. Bray and Kurtz- 9 extracted soil P concentrations were either similar or between 8.7 to 31 % greater under 10 plants of S. clarazii than under those of the other two species. The higher nutrient 11 concentration under S. clarazii than under S. gynerioides and S. tenuis may contribute to 12 explain previously measured increases in density, frequency, and cover throughout a long- 13 term span (years) in the late- than earlier-seral perennial grasses under field exclosures to 14 domestic livestock or appropriate grazing management conditions.