Phosphorus application and liming effects on forage production, floristic composition and soil chemical properties in the C ampos biome, southern B razil

Studies of responses of native and introduced grassland species to lime and phosphorus ( P ) applications could contribute to improved understanding of the potential production of S outh A merican natural grasslands. To determine the effect of applying lime and different P sources on forage production, diversity and floristic composition, and on soil chemical properties, a small‐plot experiment was conducted over 12 years in natural grassland oversown with L olium multiflorum and T rifolium vesiculosum in the C ampos of southern B razil. In treatments with soluble phosphate application, dry‐matter ( DM ) yield in November 2008, after 164 d of winter and early spring growth, increased from 2·3 to 3·2 t ha −1 . Differences in DM yield in M arch 2009, after 111 d of growth during late spring and early summer, were not significant. The DM yield in April 2010, after 419 d of growth, increased from 7·7 to 9·2 t ha −1 in the treatments with P , regardless of the P source. Increased forage yield during the slow growth period in winter was only possible with the introduction of winter‐growing species ( L . multiflorum and T . vesiculosum ) and soluble phosphate application. Assessment of annual forage yield showed that the effectiveness of G afsa rock phosphate was equivalent to that of soluble phosphates in the long term. Soluble phosphates and liming modified the botanical composition of natural C ampos grassland in the long term, but floristic diversity was not altered.