Response of some soil attributes to different land use types in calcareous soils with Mediterranean type climate in north-west of Iran

Abstract

Monitoring general variability of soil attributes is a fundamental requirement from the point of view of understanding and predicting how ecosystems yield. In order to monitor impact of different land use types on the combination of morphological, clay mineralogical and physicochemical characterizes, 42 soil samples (0-30 cm) were described and analyzed. Soil samples belonging to Cambisols and Vertisols reference soil groups collected from three neighboring land use types included cropland (under long-term continuous cultivation), grassland, and forestland. The soils were characterized by high pH (mean of 7.1-7.5) and calcium carbonate equivalent (CCE) (mean of 35-97 g kg -1 ) in the three land use types. The weakening in soil structure, hardening of consistency, and lighting of soil color occurred for the cropland under comparable condition with grassland and forest. Changes in land use types produced a remarkable change in the XRD patterns of clay minerals containing illite and smectite due the dynamic and removal of potassium. Continuous cultivation resulted in an increase in sand content up to 35 % while silt and clay content decreased up to 22 and 18 %, respectively, as compared to the adjoining grassland and forest mainly as a result of the difference of dynamic alterational and erosional process in the different land use. Long-term cultivation caused a negative and degradative aspects on soil heath as is manifested by the increasing in soil pH (a rise of 0.3-0.46 unit), electrical conductivity (EC) (a rise of 1.78-5.5 times), sodium absorption ration (SAR) (a rise of 10-51 %), exchangeable sodium percentage (ESP) (a rise of 3-46 %), and the decrease in soil organic C (a drop of 12-41 %), along with soil fertility attributes. Overall, the general distribution of soil organic C, total N, available P and K, cation exchange capacity (CEC), and exchangeable cations (Ca, Mg, and K) followed the order: forestland [ grassland [ cropland. The general distribution of EC, SAR, ESP, and exchangeable Na, however, followed the order: cropland [ grassland [ forestland. Soil quality index (SQI), calculated based on some physicochemical properties, specified that cultivation led to a negative effect in SQI for both Cambisols (a drop of 10-17 %) and Vertisols (a drop of 17 %) as compared to those of under grassland and forestland.

Response of soil properties and C dynamics to land-use change in the west of Loess Plateau

“…The variables that each principal component (PC) represents are given in Table 3. of land cultivation, abandonment and afforestion, there would be some changes in vegetation, physical soil properties including soil moisture and temperature, bulk density and aggregate stability (Zhang et al 2010;Zhu et al 2010;Raiesi 2012), and chemical soil properties (e.g. pH, EC, total N) (Zhang et al 2010;Rezapour 2014). As a consequence of these changes, activity and diversity of soil microorganisms and biochemical processes would undoubtedly be modified in the short-term.…”

A soil quality index for evaluation of degradation under land use and soil erosion categories in a small mountainous catchment, Iran

“…Soil quality degradation in Iran is widespread (Ayoubi et al 2014;Emadi et al 2009;Nosrati 2013;Raiesi 2017;Rezapour 2014). Current socioeconomic pressures in Iran pose a serious threat to soil quality and thereby both food security and environmental protection.…”

Impact of parent rock and topography aspect on the distribution of soil trace metals in natural ecosystems

“…The fate of Mn, Zn, and Fe in the topsoil (pedons 3 and 4) may be related to a process named as the biological pump or nutrient uplift. Consistent with the hypothesis, deep-rooted trees often act as pumps, uptaking metal from subsoil horizons into their root systems, translocating it to their leaves, and re-entering it to the topsoil with litter fall and decomposition, causing much higher the metals levels in the surface (Rezapour 2013). In contrast with Mn and Zn pattern, Cu and Ni were depleted from the surface soil of pedons 3 and 4 which may be attributed to the process of acidic condition (pH \6, Table 3) in the pedons because of trace metals are more solution in acidic environments (Kabata-Pendias and Mukherjee 2007).…”