Litter quality of C3 perennial grasses and soil inorganic nitrogen in a semi-arid rangeland of central Argentina

ANDRIOLI, R.J.; DISTEL, R.A.

JOURNAL OF ARID ENVIRONMENTS

Elsevier

Año: 2008 vol. 72 p. 1684 - 1689

0140-1963

The study was undertaken to quantify litter quality of six C3 perennial grasses and species effects on soil inorganic nitrogen (N) in a semi-arid rangeland of central Argentina. Leaf litter and roots were analyzed for N, carbon, phosphorus and lignin concentrations. Field measurements and laboratory experiments compared inorganic N content and potential net N mineralization in the soil under selected grasses. Species were represented by two palatable late-seral grasses (Poa ligularis and Stipa clarazii), two unpalatable late-seral grasses that increase in abundance under heavy grazing (Stipa ambigua and Stipa gynerioides) and two palatable mid-seral grasses (Piptochaetium napostaense and Stipa tenuis). Species exhibited relatively little variation in the chemical composition of leaf litter and roots. The soils associated with these species did not differ in inorganic N content in field or potential net N mineralization. Furthermore, amending soils with the roots of these species had no consistent impact on inorganic N content. Our results suggest C3 perennial grasses that differ in their palatability to grazers do not differentially influence soil inorganic N dynamic in semi-arid rangelands of central Argentina. Keywords: soil inorganic nitrogen; soil nitrogen dynamics; litter quality; C3 grasses; semi-arid rangelands; N-mineralization