Changes in Soil Organic Carbon, Nitrogen and Phosphorus in Modified and Native Rangeland Communities (Case study: Sisab Rangelands, Bojnord)
Authors
Abstract
Converting the native rangelands to simplified agronomic communities causes
some changes in soil carbon, nitrogen and phosphorus. Establishing of perennial plant
communities on formerly cultivated rangelands is expected to stabilize soil properties and
increase the amount of C, N, P stored in rangeland soils, but there is little information on what
plant communities are the most effective for improvement of soil C, N, P reserves. The
purpose of this study was to compare soil C, N, and P pools in ungrazed native rangelands
with plant community of Festuca-Centurea with those ungrazed pastures established by
sowing non-native perennial grasses (Agropyron elongatum and Agropyron desertorum),
shrubs (Kochia prostrata), and wheat cultivation in continuous dry land farming system.
Study site was located in Sisab Research Station in North Khorasan Province, Iran. The
results showed that the total C, N and P contents in the soils under modified plant
communities were less than that for native rangeland. Soils under A. elongatum, A.
desertorum and K. prostrata tended to have higher values for total C, N and P than soils
cultivated annually in wheat-fallow systems. The total C and N content of soils under K.
prostrata were near as native rangeland which suggests that K. prostrata can increase the soil
C and N contents much more rapidly than the other perennial communities.
