this study was conducted to investigate the impact of land use change on some of carbon components in safashahr area, fars province. four land uses (destroyed rangeland, agricultural land, new and old apple orchard) were selected. sampling was done randomly from two depths (0-20 and 20-50 cm) of each land use. particulate organic matter (pom) and extractable carbohydrate by hot water were measu...

A new practical and precise method for determining soil aggregate stability is described. Four air-dry aggregate fractions (<0.25, 0.25 0.5, 0.5 1.0 and 1.0 2.0 mm) were added to thoroughly stirred water in a Mastersizer 2000 laser diffractometer. The suspension obtained was passed directly through the measuring system. The dynamics of median (equivalent diameter d50) particle-size distribution...

Soil aggregate stability data are often predicted to be positively associated with measures of plant productivity, rangeland health, and ecosystem functioning. Here we revisit the hypothesis that soil aggregate stability is positively associated with plant productivity. We measured local (plot-to-plot) variation in grassland community composition, plant (aboveground) biomass, root biomass, % wa...

the effects of dominant shrub species on soil organic matter (som), including total soil carbon (sc), total nitrogen (n) and particulate organic matter (pom) were studied in three stands differing in the type of shrub species, i.e. astragalus microcephalus (shrub), pteropyrum aucheri (shrub) and prangus uloptera (non-shrub).the stands were located in arid grasslands of north-western iran. for t...

In this study, we report on the distribution and mineralogy of micron-sized mineral aggregates formed in the top horizon of an acid sulfate soil. The distribution and oxidation state of arsenic (As) and selenium (Se) were also determined. The soil used in this study was formed from pyritic shale parent materials on the east side of the California Coast Range. Synchrotron-based X-ray fluorescenc...

to study the effects of scale and tillage management on variability of soil properties in adjacent lands of different tillage type, soil sampling was performed linearly along contour line from the middle position of slope with 5 m intervals. in overall, 45 soil samples were collected from a field with conventional up-down tillage and 40 samples from an adjacent filed with contour tillage. soil ...