Abstract:

Physicochemical properties of soils （0-30 cm depth） of wild Poa habitats in Gansu Province were investigated to get information on the utilization of this plant species. The results indicated that， the mean pH， contents of soil organic matter， total N， alkali-hydrolysable N， total P， Olsen-P， available K of the soils were 7.53 mg·kg^-1， 43.5 g·kg^-1， 2.18 g·kg^-1， 121 mg·kg^-1， 0.734 g·kg^-1， 2.69 mg·kg^-1 and 302 mg·kg^-1， respectively. Coefficients of variance （CV） of soil organic matter， total N， alkali-hydrolysable N and Olsen-P ranged between 75%-100%， indicating substantial variance. Soils of Sunan （SN） and Xinglongshan Mountain （XLS） had abundant organic matter， N and P， contents of these three components were significantly greater than soils of habitats of Xiahe （XH）， Weiyuan （WY）， Anding District （AD）， Qingshui （QS）， Longxi （LX）， Kangle （KL） and Lingtao （LT）. Greater contents of organic matter， total N， alkali-hydrolysable N， total P and Olsen-P， and lower values of pH and available K were observed in the topsoil than in the lower depth. All nutrients exhibited topsoil enrichment except K. The soils of Poa habitats had greater organic matter contents than farmland soils， indicating greater carbon sequestration capacity than farmland soils. Significant correlations were observed between soil pH， habitat elevation and soil total P （P<0.05）. Significant correlations between soil organic matter content （P<0.001）， and Olsen-P （P<0.05） were found. The soils were clustered into two groups with the nutrient parameters. The results suggest that the Poa grows in habitats with great variance in nutrient status.

Key words: wild Poa pratensis, habitat, soil pH, organic matter, nitrogen, phosphorus, potassium