*Manuscript Click here to view linked References 1 Abundance, diversity and prospecting of culturable phosphate solubilizing bacteria on 2 soils under crop-pasture rotations in a no-tillage regime in Uruguay. 3 Gastón Azziza*, Natalia Bajsaa,b, Tandis Haghjoua, Cecilia Tauléa1, Ángel Valverdec, 4 José Mariano Igualc, Alicia Ariasa. 5 (a)- Laboratorio de Ecología Microbiana, Instituto de Investigaciones Biológicas 6 Clemente Estable. Av. Italia 3318. CP 11600. Montevideo, Uruguay. 7 (b)- Sección Bioquímica, Facultad de Ciencias, Universidad de la República. Iguá 4225. 8 CP 11400. Montevideo, Uruguay. 9 (c)- Departamento de Producción Vegetal, IRNASA-CSIC. C/Cordel de Merinas, 40- 10 52. E-37008. Salamanca, España. 11 *Corresponding author. E-mail:
[email protected]; Tel.: +598 2 4871616; Fax: +598 12 24875548. Correspondence address: Av. Italia 3318. CP 11600. Montevideo, Uruguay. 13 14 1Present Address: Laboratorio de Bioquímica y Genómica Microbianas, Instituto de 15 Investigaciones Biológicas Clemente Estable. Av. Italia 3318. CP 11600. Montevideo, 16 Uruguay. 17 Abstract 18 Phosphate solubilizing bacteria (PSB) abundance and diversity were examined during 19 two consecutive years, 2007 and 2008, in a crop/pasture rotation experiment in 20 Uruguay. The study site comprised five treatments with different soil use intensity 21 under a no-tillage regime. In the first year of sampling, abundance of PSB was 22 significantly higher in Natural Prairie (NP) and Permanent Pasture (PP) than in 23 Continuous Cropping (CC); rotation treatments harbored populations that did not differ 24 significantly from those in the others. The percentage of PSB relative to total 25 heterotrophic bacteria ranged between 0.18% and 13.13%.