Relationship of Potentially Labile Soil Organic Carbon with Soil Quality Indicators in Deforested Areas of Iran

Abstract

The purpose of this investigation was to study the effects of urbanization and land‐use changes on vegetation and the concentration of carbon deposits in the Ziarat watershed, a tourism area, located in Golestan Province, in northern Iran. For this reason, we selected four land uses: forest, pasture, cultivated, and urban lands. Soil samples of from the 0‐ to 30‐cm depth were taken from a factorial nest design within two geographical aspects (north and west), and with five replications for each geographical aspect. Converting forest to urban and cultivated land uses resulted in considerable losses of organic carbon (OC) and the destruction of aggregates, which caused the mean weight diameter (MWD) of aggregates to decrease from 2.54 mm to 0.35 and 1.2 mm, respectively. Compared to forest land, the labile carbon (LC) was lower in urban, cultivated, and pasture land by 87, 66, and 54%, respectively. Also nonlabile carbon was lower in urban, cultivated, and pasture land by 76, 49, and 34%, respectively. Soil microbial respiration (SMR) was lower in urban, cultivated, and pasture land (0.09, 0.14, and 0.22 mg CO2 g–1 d–1, respectively) compared with forest land (0.22 mg CO2 g–1 d–1). Statistically significant positive correlations (P < 0.0001, with R = 0.73) between stable carbon and MWD were observed. This study quantified reductions in numerous soil quality parameters resulting from extensive land‐use changes and urbanization in Iran. Effective regional land‐use planning in Iran can integrate results of this study to facilitate land development with the fewest deleterious impacts to soil quality.

Assessment and Monitoring of Soil Degradation during Land Use Change Using Multivariate Analysis

“…F2 (Ca 2+ , Mg 2+ , and Na + ), F3 (silt and sand), F4 (K + ), and F5 (SMR) explained 15·46%, 11·15%, 6·81%, and 5·9% of the total variance, respectively. Clay content is an important factor controlling exchangeable cations in forest lands (Emadi et al, ; Khaledian et al, ). The general trend showed that land use change led to a decrease of exchangeable cations and SMR in soils exposed to human activity compared with forest soils, which are the native vegetation for this area of northern Iran (Table ), which was confirmed by CA.…”

“…Soil degradation is the decline in soil quality, which encompasses physical, chemical, and biological deterioration, caused by its improper use, usually for agricultural, pasture, or urban purposes. It depends not only on the interaction of different physical, chemical, and biological factors of soil, including soil properties, topography, and climatic characteristics (Brevik et al, ; Taguas et al, ), but also on land use, anthropogenic factors, and management (Khaledian et al, ; Camprubi et al, ; Costa et al, ; Parras‐Alcántara et al, , ; Cerdà et al, ). The types of land cover are closely related to the characteristics of human activities, which in turn determine the anthropogenic substances such as pesticides and herbicides carried into erosion systems through soil detachment, runoff process, sediment transport, and deposition.…”

The Influence of Organic Carbon and pH on Heavy Metals, Potassium, and Magnesium Levels in Lithuanian Podzols

“…Biochar is a high-carbon and fine-grained residue which is produced from organic carbon under thermal decomposition in the absence of oxygen (Lehmann, 2009;Gronwald et al, 2015). Biochar as a soil amendment is used to improve soil quality over both the long and short term (Khaledian et al, 2013;Krause et al, 2016). Its reported benefits have included mitigation of nitrous oxide (N 2 O) emissions (Hüppi et al, 2015;Harter et al, 2016), improved nutrient availability (Drake et al, 2016;Olmo et al, 2016;Pandey et al, 2016), prevention of heavy metal pollution (Bian et al, 2013;Mohamed et al, 2015), general control of environmental pollution (Fernández-Calviño et al, 2016), and storage of organic carbon.…”

Effect of cover crops on physico-chemical attributes of soil in a short-term experiment in the southwestern Amazon region

“…This is due to the fact that the use of plants and straw influences the biological dynamics of soil (Franchini et al, 2007), with positive effects on overall fertility, especially in levels of soil organic matter after a few years (Maia et al, 2013). The application of organic matter to the soil over time, improves the physical and chemical conditions, specific surface area, soil stability (aggregate size) and soil organisms (Zeraatpishe and Khormali, 2012;Khaledian et al, 2013).…”