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Iron (Fe) in the soil is a very important element for agricultural applications and the development of plants, which have different forms. The presence of Fe in the rhizosphere is controlled by the activity of Fe forms in the soil and the microorganisms and surrounding root-soil interaction of plants and roots. The objectives of this study were to identify, and to examine their interaction with soil properties in vertisols. The results showed that; FeT contents ranged from 1.17 and 47.71 g kg-1, mean 13.81 g kg-1 › FeD contents 0.18 to 17.85 g kg-1 and mean 7.23 g kg-1 › FeO contents 0.01–0.31 g kg-1 mean 0.18 g kg-1 › FeDTPA contents 0.00–0.17 g kg-1 mean 0.04 g kg-1 › FeP contents 0.00–0.02 g kg-1 mean 0.01 g kg-1. Clay-silt fractions and organic matter had a very powerful impression on Fe forms distribution. FeD, FeDTPA, FeO ve FeP had low quantities. This is thought to be due to insufficient rainfall and some soil characteristics (including high pH, low organic matter, clay texture, and high lime content), as iron is not easily dissolved in the soil. There was a very important relation between clay content, organic matter, silt fractions, and Fe forms in the studied area. There was a positive correlation between soil organic carbon and DTPA-extractable Fe. There was a negative correlation between DTPA-extractable Fe and soil pH, also calcium carbonate content. When total Fe was rised, clay-silt content and cation exchange capacity (CEC) increased in the soil profiles. Especially in Zone 3 has more Fe and Fe contents, the results showed that; There was a very good balance between the different Fe fractions and soil properties. Zone 3 had more total iron contents than the other zones, because of their soil properties. Fe bound by organic sites, water-soluble plus exchangeable Fe and Fe were adsorbed onto oxides (amorphous surfaces) and were positively correlated with the DTPA-extractable Fe.

Pig slurry is considered a high-risk effluent that causes several environmental problems if it is not adequately managed and treated. White Iberian pig farms in the southeast of Spain treat their slurry in situ using separation, double filtration, decantation, and constructed wetland treatments. However, the pretreatment process does not successfully reduce solids, which leads to clogging in the constructed wetlands (CWs). The main objective of this research paper is to reduce the turbidity and chemical oxygen demand (COD) from the effluent to make it appropriate for CW treatment. Optimization of the coagulation–flocculation (CF) process using iron chloride and a cationic flocculent DKFLOCC-1598 was investigated by a central composite design method (CCD). The effects of coagulant concentration, pH, and flocculent on the COD and turbidity removal were evaluated. The best results were found using 0.024 mol L−1 iron chloride and 0.164 mL L−1 flocculent at pH 7.5, which reduced COD by 96% and delivered turbidity removal of 97%. Therefore, the results indicate the high efficiency of the treatment method in reducing the COD and suspended solids.

In semi-arid climates, the management of pig slurry is very important, since it may cause an environmental problem, but on the other hand it has positive impacts such as high labile and org...

This study reports the seasonal and spatial variations of atmospheric dust deposition rates (DDR) and dust-borne heavy metals concentrations in the city of Isfahan and its surrounding areas in central Iran. Dust samples were collected from 67 different sites on a monthly basis from June 2012 to May 2013 and topsoil samples were taken only once from the same sites. Fall and winter seasons exhibited the lowest DDR due to the higher precipitation while the highest rate was observed in the summer season. The northern and central parts of the desert land in the study area recorded the highest annual DDR with a mean value of 61.24 ton km−2 year−1. Seasonal distribution of dust-borne heavy metals concentrations showed that almost all the elements followed the trend winter > fall ≥ spring > summer. Spatial distributions of dust-borne Cd, Cu, Ni, Pb, and Zn almost followed the same pattern with highest concentrations in the western stretches of the study area and in the city of Isfahan. The highest concentration of Hg and As were observed in the urban and desert rural areas. Cr recorded its highest concentration in the urban area while dust-borne Co exhibited a fairly uniform distribution over the whole study area. Results of crustal enrichment factor (EFc) analysis showed that anthropogenic sources contribute a substantial amount of all studied elements in dust particles rather than crustal origin. Fossil fuel, vehicle traffic, and industrial activities seem to be the most important anthropogenic factors responsible for dust elemental pollution in the study area.

The socio-economic activities in Morocco and Spain as well as all the other countries around the world involving population growth and changes in consumption behavior have generated a substantial and important solid waste production. The decomposition of waste by microorganisms in landfills generates soluble compounds, which under the leaching action and water infiltration meteorites come to mix together forming “leachate juices”. Its composition varies widely depending on the age of the landfill and the type of waste it contains. The latter usually contains dissolved and suspended material. This study aims to characterize the physicochemical properties and evaluate the mineral and organic compounds of different leachates. It is worthy to note that this physicochemical characterization is arbitrary because those landfills willsoon be equipped with an elimination center and treatment. The following objectives of this paper have been set for this work; on one hand, to determine the qualitative characteristics aspects of leachates that are essential for characterizing the pollutant load and, thus, estimating the risks that these leachates pose to the water quality of the surrounding groundwater. On the other hand, it aims to propose a cost effective and efficient leachates treatment processes and also serves as a stepping stone reference for future leachate research. The desired process aims at obtaining a very significant reduction in the organic load of the leachate and thus could be replicated in other current and future releases. To achieve this characterization, we carried out a series of leachate sampling from different regions in Morocco (Casablanca and Marrakech) and Spain (ULEA and Orihuela). This sampling was carried out for the purpose of making a comparison between the evolutions of their qualities, and it also allows us to know the statue of those landfills.

Tree leaves are considered as one of the best biogenic dust collectors due to their ability to trap and retain particulate matter on their surfaces. In this study, the magnetic susceptibility (MS) and the concentration of selected heavy metals of plane tree (Platanus orientalis L.) leaves and deposited atmospheric dust, sampled by an indirect and a direct method, respectively, were determined to investigate the relationships between leaf magnetic parameters and the concentration of heavy metals in deposited atmospheric dust. The objective was to develop a biomagnetic method as an alternative to the common ones used for determining atmospheric heavy metal contaminations. Plane tree leaves were monthly sampled on the 19th of May to November, 2012 (T1-T7), for seven months from 21 different sites in the city of Isfahan, central Iran. Deposited atmospheric dust samples were also collected using flat glass surfaces from the same sites on the same dates, except for T1. MS (χlf, χhf) values in washed (WL) and unwashed leaves (UL) as well as Cu, Fe, Mn, Ni, Pb, and Zn concentrations in UL and deposited atmospheric dust samples were determined. The results showed that the MS content with a biogenic source was low with almost no significant change during the sampling period, while an increasing trend was observed in the MS content of UL samples due to the deposition of heavy metals and magnetic particles on leaf surfaces throughout the plant growth. The latter type of MS content could be reduced through washing off by rain. Most heavy metals examined, as well as the Tomlinson pollution load index (PLI) in UL, showed statistically significant correlations with MS values. The correlation between heavy metals content in atmospheric dust deposited on glass surfaces and leaf MS values was significant for Cu, Fe, Pb, and Zn. Moreover, the similarity observed between the spatial distribution maps of leaf MS and deposited atmospheric dust PLI provided convincing evidence regarding the suitability of the biomagnetic approach as a relatively rapid and inexpensive method for identifying highly polluted urban areas with selected heavy metals, especially those subjected to anthropogenic and other traffic related sources.

The labile pools of soil organic matter enable assessment of the variation in land use changes and other management practices. This study aims to: (1) examine the effect of forest (F) and pasture (P) conversion on total and labile forms of soil organic C (SOC), (2) quantify the relationship among different labile SOC, and (3) determine whether labile SOC fractions are more sensitive indicators of soil quality than total organic C (TOC) after F and P conversion to agricultural use (forests converted (F to A) and pasture converted (P to A) soils) in southwestern Iran. Accordingly, composite soil samples with eight replicates were collected from 0–15 cm of each land use in December 2014. The samples were then analyzed for TOC, microbial biomass C, permanganate oxidizable C, and cold- and hot-water extractable organic C. The results illustrated that the TOC and all labile pools of soil organic carbon followed the trend: F > P > F to A > P to A. However, from the four land uses studied, P soils showed a better and different quality of organic C than other land use systems, which was indicated by the highest proportion of microbial biomass C (3.3%), permanganate oxidizable C (4.8%), and cold- (0.55%) and hot-water extractable organic C (3.7%), but the lowest proportion of non-labile C (95.2%) to the TOC contents of the soils. The highest amounts of SOC stocks were spotted in the F soils (42.1 Mg ha − 1 ) followed by P (29.7 Mg ha − 1 ), F to A (26.7 Mg ha − 1 ) and P to A (19.5 Mg ha − 1 ) land use systems. Accordingly, organic carbon storage of the soils decreased by land use conversion from F (36.6%) and P (34.3%) to agriculture. The carbon management index, whose variation was mainly caused by carbon pool index, was higher in P to A soils than F to A soils suggesting that organic C compounds are less degraded and contain higher amounts of labile C than F to A soils. The results also showed that labile organic carbon pools are more sensitive to changes in management practices than TOC contents of the soils. However, a single carbon pool cannot be used as the most sensitive indicator of soil quality to reflect land use differences. The permanganate oxidizable C, hot water extractable organic C and microbial biomass C demonstrated the highest sensitivity to the land use induced changes in forest soils and cold water extractable organic C and microbial biomass C were realized as the most sensitive parameters in pasture conversion to arable lands. In conclusion, it seems that the quality of both F and P soils was decreased with adoption of agriculture and therefore sustainable management practices should be employed in order to achieve soil stability and biological productivity in the area.

Monitoring soil carbon content and pools and associated enzyme activities has become an important area of research in terms of the carbon cycle in agricultural lands in order to infer factors regulating soil carbon sequestration. Pig slurry (PS) is considered as a source of organic matter and nutrients for crop production. In recent years, because of the cost of conventional feed applications, manufacturers have preferred liquid feeding diets with decreases of 10–25% in production costs. Furthermore, physical and chemical filtration of PS by new techniques may prevent soil degradation and reduce the negative effects of PS, such as high salt, pathogen, and heavy metal contents. This research aimed to assess the effect of the application of raw pig slurry (R) and treated pig slurry (T) (derived from physical and chemical separation processes) from liquid (L) and solid (S) feeding diets on different soil organic carbon pools and enzyme activities in a sandy loam soil under a rainfed barley cropping system for two years. The solid diet consisted of maize/soya bean, tubers and roots, and supplementary vitamins and minerals. The liquid diet consisted of dairy products such as fresh whey, concentrated cheese or yogurt, skim milk powder, and beer by-products such as brewer's yeast. As a general pattern, the addition of the different types of PS (R or T) had no significant effect on most soil properties, except for microbial biomass C (Cmic), which increased with R. However, the type of diet did have a significant effect on most properties, both for R or T slurries, suggesting that this is more of a determinant factor in explaining changes in soil than the type of pig slurry. Solid diet favors the significant increase of soil organic carbon and arylesterase activity, suggesting higher stabilization of the organic compounds provided by the PS. However, the liquid diet contributed to increasing soluble C and Cmic, suggesting higher availability of nutrients and C sources. Hence, the use of treated pig slurry has no detrimental effect on organic carbon dynamics compared to raw pig slurry and can be suggested as an alternative to reduce the environmental impact, prevent soil pollution, and ensure sustainability.

Little is known about the distribution and origins of palygorskite in soils developed on Tertiary and Cretaceous rocks and sediments and the associated soils in such areas as Fars Province, southern Iran, or the other Middle Eastern countries. The present study pursued the twofold objective of (1) identifying the distribution and sources of palygorskite in the soils developed on the above sediments and (2) determining the major soil properties influencing palygorskite distribution. Eight soil profiles developed on Cretaceous and Tertiary sediments and their parent materials were sampled and studied using XRD, SEM, and EDX analyses. The results revealed that most of the palygorskite was inherited from the respective parent materials although some seemed to be the product of neoformation pathways as a result of gypsum and calcite precipitation. Principal component analysis revealed that the most significant factors affecting the distribution and genesis of palygorskite in the soils developed on Cretaceous sediments are electrical conductivity (EC), clay, soluble Si, organic C, calcium carbonate equivalent (CCE), and smectite while those for Tertiary parent material-derived soils are the amounts of gypsum, illite, organic C, and CCE. Multiple regression analysis suggested smectite, pH, gypsum, and EC in the Cretaceous samples and the values of gypsum and soluble Ca and Si in the Tertiary soils as indicators to be used for predicting palygorskite content.

Phytoextraction is a green technique for the removal of soil contaminants by plants uptake with the subsequent elimination of the generated biomass. The halophytic plant Suaeda vera Forssk. ex J.F.Gmel. is an native Mediterranean species able to tolerate and accumulate salts and heavy metals in their tissues. The objective of this study was to explore the potential use of S. vera for soil metal phytoextraction and to assess the impact of different chelating agents such as natural organic acids (oxalic acid [OA], citric acid [CA]), amino acids (AA) and Pseudomonas fluorescens bacteria (PFB) on the metal uptake and translocation. After 12 months, the highest accumulation of Cu was observed in the root/stem of PFB plots (17.62/8.19 mg/kg), in the root/stem of CA plots for Zn (31.16/23.52 mg/kg) and in the root of OA plots for Cr (10.53 mg/kg). The highest accumulation of metals occurred in the roots (27.33-50.76 mg/kg). Zn was the metal that accumulated at the highest rates in most cases. The phytoextraction percentages were higher for Cu and Zn (∼2%) with respect to Cr (∼1%). The percentages of metal removal from soil indicate the need to monitor soil properties, to recognize the influence of each treatment and to increase the concentration of bioavailable metals by the use of agricultural management practices aimed at promoting plant growth.

Durum wheat (Triticum turgidum durum (Desf.) Husn.) is produced on a large scale in Turkey, northern Syria, Kazakhstan, Iran, southern Europe, and North America, and is widely used for making spaghetti, noodles, couscous, and flatbreads. Uptake of Cd by durum wheat species is well known. The objectives of this study were to determine the cadmium (Cd) level of the soils and durum and bread wheat grown on Harran Plain, southeast Turkey, and evaluate it in terms of food safety. Soil samples were taken from 16 selected grains, leaves, and roots of durum and bread wheats for analyses. The total Cd contents of the surface and subsurface horizons were below the internationally acceptable threshold levels (2 ppm of Cd. The amounts of bioavailable Cd in bread wheat were lower than those in durum wheat. However, the bioavailable Cd contents in durum wheat grains were 0.1 mg kg-1). A lower Cd content was attributed to the presence of high amounts of carbonates (>20%), Fe-oxy-hydroxides (>5%), clay percent (>50%), and the nature of silicate clay mineralogy in the soils we studied. Durum wheat cultivars used in the area could be another reason for the lower contents of Cd. We confirmed that durum wheat grown on Harran Plain in southeast Turkey is quite suitable for consumption from the standpoint of Cd contents.

Limited studies have been conducted on atmospheric dust pollution due to high cost of instrumental monitoring and difficulties in associated sampling methods. In this study, the possibility of using leaves of plane tree ( Platanus orientalis L.) as a bioindicator of atmospheric pollution was evaluated by determining the composition of heavy elements in both the tree leaves and the atmospheric dust. Plane tree leaves were sampled monthly for 7 consecutive months (May to Nov.; T 1 –T 7 ) from 21 different sites in the city of Isfahan, central Iran. Atmospheric dust samples were also collected from the same sites on glass trays simultaneously, except for T 1 . Concentrations of Cu, Fe, Mn, Ni, Pb, and Zn were determined in both the washed (WL) and unwashed leaves (UL) as well as in the atmospheric dust samples. Elemental concentrations in the dust samples deposited on the leaves were determined by subtracting metal concentrations in UL from those in WL. Significant amounts of heavy metals were detected in UL taken from all sites at all the sampling times except for T 7 before which time a heavy rain had fallen. Statistically significant correlations were found between the heavy metal concentrations in the atmospheric dust and the dust deposited on the leaves (UL–WL) except for Pb in T 4 and T 5 sampling times. The spatial distribution maps of heavy metal concentrations in atmospheric dust followed almost the same pattern as those in plant leaf dust. The results showed that plane tree leaves have a great potential for use as an indicator of air pollution for all the heavy metals investigated except for Pb. This passive dust sampling and pollution accumulating method appears to be an easy, inexpensive, and accessible approach for the detection of atmospheric heavy metals.

The environmental effects of extensive mineral extractions have been the focus of recent remediation efforts in the Poopo and Uru-Uru lakes (Bolivia). Our study determined the chemical and mineral composition of salt and water samples collected in mine areas (MA) and natural sites [basin and lakes (BL), Salar de Uyuni (SU)] in the Oruro mining district. The laboratory techniques that we used included X-ray diffraction, scanning electron microscopy and total elemental analysis. Results revealed that salt samples in SU sites were dominated by halite, while thenardite, halite and konyaite were observed in BL. Sites in MA had > 15 species of sulphates, oxides, hydroxides and other minerals. Metals such as Au, Ba, Cd, Co, Cr, Cu, Li, Ni, Pb, Sn, Sc, and Zn were elevated in salt samples in MA sites compared to BL and SU sites. Salts in MA sites had lower pH (3.2) than BL (pH = 9.6) and SU (pH = 8.0). In MA sites, dissolution of minerals during the rainy season may mobilize metals from terrestrial (e.g., tailing deposits) to aquatic environments. We can conclude that mining activities combined with some natural metal mobilization events such as dissolution of salt efflorescence on rainy days and oxidation of pyrites may degrade the quality of water and land in the region.

The aim of this study was to investigate the possibility of using cottonseed hulls (CSH) and olive press cake (OPC) as new supplement materials for substrate preparation in Hericium americanum cultivation. Some chemical properties of the substrates prepared by mixtures of oak sawdust (OS) with wheat bran (WB), CSH and OPC in different ratios were determined. In addition, the effect of mixtures of OS:CSH and OS:OPC on spawn run time, yield and biological efficiency (BE), average mushroom weight and nutrition content of the fruiting body were compared with the control substrate (8OS:2WB).The yield, BE and average mushroom weight of substrates containing CSH and OPC were higher than the control substrate and increased with an increase in the rate of CSH and OPC in the mixtures. Hericium americanum showed (on a dry weight basis) 8.5-23.7% protein, 9.9-21.2 g kgThe results revealed that CSH and OPC could be used as new supplement materials for substrate preparation in H. americanum cultivation. © 2016 Society of Chemical Industry.

Few studies have been reported on the characteristics of dust particles deposited in arid regions of the Middle East. The objective of this study was to identify the variations in physical, chemical, and mineralogical composition of dust particles deposited along an elevational transect lying between central Iran and the Zagros Mountains in the west. Dust samples were collected at 12 localities during September 2008 and July 2009 with and without transboundary dust storms, respectively. Samples were examined for their grain size distribution, and their mineralogical and chemical composition. Surface soils were also sampled from the vicinity of the dust sampling sites and their total elemental compositions were determined. The results indicated that dust deposition rate, mean particle diameter, and concentration of soluble ions in samples from both sampling periods decreased with altitude, with a significantly lower gradient for samples of July 2009 than for those of September 2008. The similarity observed in dust samples taken during September 2008 and those reported by previous studies or measured in local soils and sediments suggests that local soils greatly contribute to the atmospheric dust along the transect in periods with no dust storms. During such periods, dust deposits in the high altitude Zagros Mountains, where annual precipitation is higher and temperature lower, only receive a minor contribution from arid soils of central Iran. However, in July 2009, when a heavy dust storm took place, significant differences were observed between local soils and dust samples along the transect, particularly at high altitudes, in terms of their physicochemical and mineralogical characteristics. These findings, together with satellite images and patterns of wind frequency and direction, clearly indicate the major contribution of a transboundary dust storm, probably originating from Iraqi arid land, to atmospheric deposition in the Zagros area and central Iran. When dust storms blow from across the borders, the contribution of local soils and sediments to aerosols drastically decreases with elevation. If dust storms originating from outside the country continue to occur, not only will they influence the surface soil properties in the Zagros region but will also induce environmental problems in the region.

Few studies have investigated the formation or instability of palygorskite under the influence of groundwater. This study aims to identify the effects of a saline and sodic groundwater on the formation of palygorskite and the associated clay minerals. Four pedons along a calcareous catena with different depths of groundwater were sampled and analyzed using X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and inductively coupled plasma mass spectrometry. Chemical compositions of both the groundwater and soil samples were also determined. Results revealed the presence of palygorskite, smectite, illite, chlorite, quartz, and feldspar in the soils studied. The highest amount of palygorskite was found in horizons with permanent groundwater. In surface horizons, palygorskite could not be detected by X-ray diffraction, but its presence, although in trace amounts, was confirmed by transmission electron microscopy. In most of the pedons studied, smectite showed an inverse trend, decreasing with depth, as compared with palygorskite. Stability diagrams for the smectite-palygorskite system showed that geochemical conditions were conducive to the formation of palygorskite from smectite under the influence of Mg-rich groundwater. Growth of palygorskite fibers on halite and calcite crystals, as revealed by scanning electron microscopy observations, clearly indicated in situ formation of palygorskite. The chemical composition of groundwater in the study area showed high concentrations of soluble Mg 2+ and silica, both of which are necessary for the formation of palygorskite from solution. In conclusion, palygorskite seems to have been formed in partially or entirely submerged horizons through smectite transformation or in situ formation.

About 2,341 pig farms generate large amounts of slurry in the southeastern Region of Murcia, Spain. Given the nature of the pig slurry as well as its amount produced in livestock, it has become a matter of growing environmental concern. The control of slurry ponds is now a top priority concern to create a safer environment, especially for agricultural production. This study reports the results of a much wider and comprehensive project carried out to collect reliable data on the behavior of slurry, soil, and the infiltration of slurry ponds under semiarid climate. The two-dimensional (2-D) electrical resistivity imaging (ERI) technique was used to qualitatively evaluate the natural permeability of the soils and depth that slurry had reached. The results obtained have shown that ERI is a useful tool in mapping the infiltration, as well as monitoring seasonal changes in the pollutant plume underneath the slurry ponds.

Mine tailing ponds are environmental hazards because of high susceptibility to leaching and erosion by water and wind. Vegetation establishment is an effective technique to reclaim tailing ponds but requires knowledge of the spatial relationship between the structural composition and physical and chemical properties of soils. In this study we have demonstrated the use of electrical resistivity imaging (ERI), combined with soil chemical analyses, to determine the structural and chemical composition of mine tailing ponds to assess efficient measures of environmental protection. We used a Syscal R1 resistivity meter to generate two-and three-dimensional (2-D∕3-D) ERI images from El Lirio and Brunita mine tailing ponds. Soil samples were collected at [Formula: see text] intervals to a depth of [Formula: see text], and were analyzed for pH, electrical conductivity and cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) contents. Results show that materials in the ponds can be classified into three categories: fine tailings—low ER [Formula: see text], coarse waste rock—intermediate ER [Formula: see text], and bedrock—high ER [Formula: see text]. Our interpretation of the 2-D∕3-D ERI images with respect to the historical depositions of materials in the ponds show that at El Lirio, decant water outlet was initially at the center and advanced to the east of the tailing pond as the mining activities progressed. At Brunita, the intermediate ER values on the west side of the pond marked the deposition of coarse waste rock materials released during a pond breakage in 1972. The ERI helped us image the spatial distribution of tailings and its qualitative spatial correlation with chemical properties (i.e., pH, EC, metals content). Low ER values are related to high amounts of Zn, Pb, Cu and Cd. These qualitative relationships underlie the usefulness of the combined geophysical and soil chemical approaches to improve our understanding of the properties of mine tailing ponds in the Sierra Minera (and other parts of the world).

Cadmium is a toxic pollutant, but the relationships between morphological modifications and Cd accumulation in different organs, as well as the physiological impact of accumulated Cd in leaves of different ages, remain an open question. We compared Cd concentration in the primary branches and main stems of the perennial shrub Zygophyllum fabago L. Six weeks of treatment with 10 mM Cd inhibited stem elongation and axillary bud development, and Cd accumulated to a higher level in the oldest leaves on the main stem than in ramification leaves. Although ramifications always contained lower amounts of Cd than main-stem leaves, ramification leaves were more sensitive to the pollutant. While Cd accumulation induced stomatal closure, a decrease in carbon isotope discrimination, and an increase in the water use efficiency of main-stem leaves, an inverse trend was recorded for primary-branch leaves. Cadmium induced an increase in chlorophyll concentration in the main stem but decreased it in lateral branches. Bypass flow, quantified by the 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt fluorescent dye, correlated significantly with Cd accumulation in leaves, suggesting that it contributes to Cd translocation through the transpiration stream. Our study demonstrates that Cd absorbed by the roots is unevenly distributed in the shoot leaves. Accumulated toxic ion, however, is not the only factor conditioning the organ response; for example, the physiological status of the tissues in relation to the leaf ontogeny may directly influence the extent of metabolic disorders resulting from Cd accumulation.

The use of pig slurry (PS) as a fertilizer has been practised for a long time. Direct application to soils at an adequate level influences the soil organic matter and quality positively, a critical component of soil fertility and productivity. Organic manure is considered as a source of slow-release nitrogen (N) fertilizer. High initial applications to build up the organic pool and cut back in subsequent years would be appropriate. In supplying the nutrient requirements, the amount of manure applied can be calculated based on the rate of N applied and the rate of organic N mineralization in the application season. There are many factors to be considered when attempting to assess the overall net impact of a management practice on soil quality and productivity. Additions of manure to soils at agronomic rates to match crop nutrient requirements are expected to have a positive impact on soil quality and productivity. Salinity impacts and overloading of both functional and non-functional elements can negate these benefits when manure is overapplied or applied to soils with limitations in drainage and buffering capabilities.

Soils in arid and semi-arid regions are strongly affected by the accumulation of carbonates, gypsum and other, more soluble, salts. Carbonates and gypsum both have a considerable influence on soil properties, especially the chemical properties of the soil solution. The development of reliable, fast and inexpensive methods to quantify the amounts of carbonates and gypsum in soil is therefore important. Visible and near infrared (vis-NIR) spectroscopy is a non-destructive, rapid and cheap method for measuring several soil properties simultaneously. However, research on vis-NIR spectroscopy in quantifying carbonates and gypsum is limited. Therefore, this study evaluated the efficiency of vis-NIR spectroscopy in quantifying carbonates and gypsum in surface soils using partial least-squares regression (PLSR) compared with standard laboratory methods and compared PLSR with a feature-specific method using continuum removal (CR). Carbonates and gypsum in a total of 251 sieved and air-dried topsoil samples from Isfahan Province in central Iran were measured by standard laboratory methods and vis-NIR spectroscopy (350–2500 nm wavelength range). In parallel, PLSR and the feature- specific method based on CR spectra were used to predict carbonates and gypsum. The PLSR model efficiency ( E) for carbonates and gypsum in the validation set was 0.52 and 0.80, respectively. The PLSR model resulted in better predictions than the feature-specific method for both soil properties. Because of the unique absorption features of gypsum, which did not overlap with other soil properties, predictions of gypsum resulted in higher E values and lower errors than predictions of carbonates.

The optimal detection and quantification of contamination plumes in soil and groundwater by petroleum organic compounds, gasoline and diesel, is critical for the reclamation of hydrocarbons contaminated soil at petrol stations. Through this study it has been achieved a sampling stage optimization in these scenarios by means of the location of potential contamination areas before sampling with the application of the 2D electrical resistivity tomography method, a geophysical non destructive technique based on resistivity measurements in soils. After the detection of hydrocarbons contaminated areas, boreholes with continuous coring were performed in a petrol station located in Murcia Region (Spain). The drillholes reached depths down to 10 m and soil samples were taken from each meter of the drilling. The optimization in the soil samples handling and storage, for both volatile and semi-volatile organic compounds determinations, was achieved by designing a soil sampler to minimize volatilization losses and in order to avoid the manual contact with the environmental samples during the sampling. The preservation of soil samples was performed according to Europe regulations and US Environmental Protection Agency recommendations into two kinds of glass vials. Moreover, it has been taken into account the determination techniques to quantify the hydrocarbon pollution based on Gas Chromatography with different detectors and headspace technique to reach a liquid-gas equilibrium for volatile analyses.

Effective application of organic residues to reclaim soils requires the optimization of the waste management to minimize CO2 emissions and optimize soil C sequestration efficiency. In this study, the short-term effects of pig slurry amendment alone and together with marble waste on organic matter mineralization in two tailing ponds from Cartagena-La Unión Mining District (SE Spain) were investigated in a field remediation experiment. The treatments were: marble waste (MW), pig slurry (PS), marble waste + pig slurry (MW+PS), and control. Soil carbon mineralization was determined using a static chamber method with alkali absorption during 70 days. Soil respiration rates in all plots were higher the first days of the experiment owing to higher soil moisture and higher mean air temperature. MW plots followed the same pattern than control plots, with similar respiration rates. The addition of pig slurry caused a significant increase in the respiration rates, although in MW+PS plots, respiration rates were lower than in PS plots. The cumulative quantities of C-CO2 evolved from the pig slurry mineralization were fitted to a first-order kinetic model explaining 90% of the data. This model implies the presence of only one mineralisable pool (C0). The values of the index C0*constant rate/added C were similar for PS plots in both tailing ponds, but lower in the MW+PS treatment, suggesting that the application of marble reduces the degradability of the organic compounds present in the pig slurry. Thus, the application of marble wastes contributes to slow down the loss of organic matter by mineralization.

The 5th International Conference on Land Degradation held at the Mediterranean Agronomic Institute of Bari, Italy in September 2008 brought together some 100 people from 37 countries worldwide. A number of international organisations, like FAO, IAEA, EC, and CIHEAM were also present. The conference was split into 8 sessions where 83 papers (43 oral) were presented. In total 235 abstracts were received. The main outcome was that the fight against land degradation and desertification could be successful if the right policy instruments are put in place and most importantly when local people are both authors and actors of the development process. Moreover, soil conservation and restoration should be one component of an integrated ecosystem management strategy that should include also water, biodiversity, livelihoods and human impacts on ecosystems. There are numerous positive results when dealing with land degradation worldwide. They should be used to emphasise the urgent needs for further actions to accelerate and scale up progress and not to induce complacency. Improved land resources management measures should build on scientific evidence, local innovation and knowledge and be locally tested and validated before being applied at larger scale. Natural resource base conservation should continue to be a priority for national governments and international organisations but Africa requires particular attention. The recent financial, economic and food global crisis should not overshadow the urgent needs to deal with natural resource management and conservation and mitigate climate change impacts.

Six areas developed on metamorphic and igneous parent materials were selected in Murcia Province (SE Spain), two from diabases, two from mica schist and two from andesites. Three of them potentially polluted by anthropogenic sources and the other three no polluted. One profile and 6 surface samples were collected from each one in order to identify the Pb and Zn concentrations bounded to different soil phases using sequential extraction and to verify if the existent differences in Pb and Zn concentrations from soils developed on the same parent material are the consequence of the anthropogenic activities, or natural geochemical contributions. The results showed that the soils that present higher total Pb and Zn concentrations that come from anthropogenic sources registered higher percentages of these heavy metals in the most labile phases (exchangeable and organic matter bounded heavy metals). In addition, the carbonate phase is also an important sink of metals, however in soils developed on metamorphic and igneous rocks this constituent is very low due to organic and exchangeable phases that retain these metals. This behaviour increases the risk of mobility to trophic chain to plants and microorganisms that may absorb these metals.

The Cartagena–La Union Mining District in southeast Spain is an example of a lead-polluted site that exhibits a wide range of environmental problems. Risks associated with the high concentrations of heavy metals present, especially lead, and their large affected surface areas make such sites excellent candidates for phytostabilization. However, for the Cartagena–La Union Mining District, there were several factors, including the chemical and physical properties of the soil and the warm, semiarid climate, that made revegetation a very difficult task.