ABSTRACT
Vegetation and aggregate size effect on organic forms of soil.

Mabel E. Vázquez1, Andrea E. Pellegrini1, Gabriela Diosma1
 

Vegetable species interact with soil to establish the particular dynamics of its organic matter, and condition its microbiological activity, especially for the quantities and nature of the provided residue. The aim of this paper is to evaluate the incidence of arboreal and herbaceous species in the microbial biomass, and the total and light carbon (Ct, Cl) and nitrogen (Nt, Nl) in fractions of different sizes of the superficial horizon of a typical Argentinean Argiudol. The results obtained allow the following conclusions: the concentrations of Ct, Cl and Nt were considerably higher in the fractions above 0.1 mm; the concentration of Ct, Cl, Nt and Nl, adjusted for the weight of the fraction, was considerably higher for the fraction between 0.2 and 0.5 mm; the concentration of Nl and Cl/Ct and Nl/Nt relations showed interaction effects between the fraction size and the kind of vegetation. No statistically significant differences in the microbial biomass were detected.

Keywords: nitrogen, carbon, microbial biomass
1 Universidad Nacional de La Plata, Facultad de Ciencias Agrarias y Forestales, CC 31, La Plata (CP 1900), Buenos Aires, Argentina. E-mail: mevazquez@infovia.com.ar.