ARS | Publication request: Survey of soil properties under three different land uses in the Kukart watershed of Jalal-Abad region in Kyrgyzstan

Submitted to: Applied and Environmental Soil Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 30, 2012
Publication Date: N/A

Interpretive Summary: Surveys of soil properties related to soil functioning for certain regions of the world are still needed. Kyrgyzstan is a mountainous country located in the north-eastern part of Central Asia with altitudes that range from 500 to 5000 m above sea level creating diverse ecological landscapes. In the Kukart watershed, for example, common land uses include nut-fruit forests, grasslands used as open pastures for livestock and cultivated fields for crops such as cotton and corn. This region is especially important for the nut industry where some of the largest walnut forests exist in nearly pure stands. Our study established ranges of chemical [soil organic matter (SOM), pH and total N (TN)], physical (soil texture), and biochemical (six enzyme activities of C, N, P and S cycling) properties in nine soil profiles from this watershed. The soil profiles represented different soil orders (Inceptisols, Alfisols and Mollisols) and land uses (cultivated, nut-fruit forests, and pasture). The Sierozem (Inceptisols) soils had the highest pH levels and contained the lowest SOM and TN contents compared to the Brown, Black-brown and Meadow-steppe soils (Alfisols and Mollisols). The enzymatic activities within surface horizons (0-18 cm) typically decreased in the following order: forest > pasture > cultivated. Among the forest sites, an Inceptisol site (Sierozem) had the lowest enzyme activity and SOM content. The relatively low enzyme activities under cultivation compared to pasture and forest ecosystems and lower values under Inceptisols can serve as soil quality indicators for land use decisions in the watershed.

Technical Abstract: Surveys of soil properties related to soil functioning for many regions of Kyrgyzstan are limited. This study established ranges of selected chemical [soil organic matter (SOM), pH and total N (TN)], physical (soil texture), and biochemical (six enzyme activities of C, N, P and S cycling) characteristics for nine profiles from the Kukart watershed of Jalal-Abad region in Kyrgyzstan. These profiles represent different soil orders (Inceptisols, Alfisols and Mollisols) and land uses (cultivated, nut-fruit forests, and pasture). The Sierozem (Inceptisols) soils had the highest pH levels and contained the lowest SOM and TN contents compared to the Brown, Black-brown and Meadow-steppe soils (Alfisols and Mollisols). The enzymatic activities within surface horizons (0-18 cm) typically decreased in the following order: forest > pasture > cultivated. Enzyme activity trends due to land use were present regardless of elevation, climate and soil types although subtle differences among soil types within land use were observed. For example, among the forest sites, an Inceptisol site (Sierozem) had the lowest enzyme activities and SOM values. The relatively low enzyme activities under cultivation compared to pasture and forest ecosystems and lower values under Inceptisols can serve as soil quality indicators for land use decisions in the watershed.