Investigation of land use changes in rural areas using MCDM and CA-Markov chain and their effects on water quality and soil fertility in south of Iran

The purpose of the study is to predict drought changes in Dariun, Fars Province, and their impact on water and soil quality. To prepare drought, water, and soil quality zoning maps, Landsat satellite images and the kriging method were used. The fuzzy maps and weights for each parameter were then determined using fuzzy and analytic hierarchy process (AHP) methods. Additionally, cellular automata (CA)-Markov chains were used in order to predict the impact of drought changes on water and soil quality. Using the fuzzy-AHP method, water quality and soil fertility in 2020 were lower compared to previous years, mainly because of land use changes that increased pollution. Based on results of the Markov and CA-Markov chains, approximately 31% of the region will have very poor levels of soil fertility and water quality in 2050. Further, based on remote sensing indicators, it is determined that about 25% of the region will be at high risk of drought in 2050. Thus, if adequate management of the region is not done, the possibility of living in these areas may diminish in the coming years due to drought and deteriorated water and soil quality.

     

土壤有机物污染控制标准制订的方法学研究

指出了中国现行土壤环境质量标准存在的问题.对日本和美国等发达国家的有机物污染土壤质量控制标准进行了分析.从土壤环境质量基准制订的方法学和污染控制标准的确定原则上,提出了制订中国土壤有机物污染控制标准的建议.     

Spatial extraction model for soil environmental quality of anomalous areas in a geographic scale

An approach to establish a soil environmental assessment model was proposed to evaluate the soil environmental quality level. The kriging technique and a self-organizing map (SOM) were integrated to investigate the soil environmental quality in a geographic information system (GIS). In this study, SOM was applied to categorize the data set of nine heavy metals in topsoil. A total of 261 topsoil samples were collected to determine the concentrations of Cu, Pb, Zn, Cd, Ni, Cr, Hg, As, and Mn. The samples were clustered into three classes by SOM and visualized by GIS. The results show that different environmental quality categories are significantly different and that the soil environmental quality assessment model is effective.     

Prediction of Cadmium uptake by brown rice and derivation of soil–plant transfer models to improve soil protection guidelines

Cadmium (Cd) levels in paddy fields across Taiwan have increased due to emission from industry. To ensure the production of rice that meets food quality standards, predictive models or suitable soil tests are needed to evaluate the quality of soils to be used for rice cropping. Levels of Cd in soil and rice grains were measured in 19 paddy fields across the western plains in Taiwan. Cadmium levels in soil range from less than 0.1 mg kg^?1 to 30 mg kg^?1. Measured Cd levels in brown rice were predicted very well (R² > 0.8) based on Cd and Zinc in a 0.01 M CaCl₂ extract or a soil–plant transfer model using the reactive soil Cd content, pH, and cation exchange capacity. In contrast to current soil quality standards used in Taiwan, such models are effective in identifying soils where Cd in rice will exceed food quality standards.     

Short-term exposure to ozone altered the relative feed value of an alfalfa cultivar

Biomonitors are organisms that provide quantitative information on environmental quality. There are some constraints and limitations for the use of plants as biomonitors of soil pollution, as pointed out recently by some authors in this journal. However, we defend the use of plants as biomonitors, and argue that they have important advantages over soil analyses as indicators of soil quality, particularly when investigations are made on a large scale.     

Influence of soil physical properties and vegetation coverage at different slope aspects in a reclaimed dump

Vegetation coverage is an important parameter for affecting soil erosion and the physical and chemical properties of soil. To analyze the mutual influence between vegetation coverage and soil quality at different slope aspects in a reclaimed dump, fitting analyses were built between the normalized difference vegetation index and soil physical properties at each slope aspect. Twenty six quadrats were sampled in slope-platform alternate mode. Each quadrat was 10 m × 10 m. Vegetation index and soil physical properties were measured and calculated. Through curve fitting analysis, the results showed that soil bulk density has a negative correlation with the vegetation index on shady and half shady slopes, sunny slopes, and half sunny slopes. Soil porosity has a positive correlation with the vegetation index on shady and half shady slopes, sunny slope, and half sunny slope. The soil mass water content has a concave function relationship with the vegetation index on shady and half shady slopes and has a quadratic function relationship with the vegetation index on sunny and half sunny slopes, with the parabola moving upwards. The soil gravel content has a linear relationship with the vegetation index on shady and half shady slopes, and the image has a negative slope with a quadratic function relationship to the vegetation index on sunny slope and half sunny slope, with the parabola moving downwards. Due to differences among hydrothermal conditions, the relationship between vegetation coverage and soil quality indicators at different slope aspects is different; therefore, reasonable improvement of soil quality indicators on sunny and half sunny slopes could help plants to grow. These findings feed into a reference document that sets out how vegetation and soil quality may be improved in mining areas.

     

A framework of connections between soil and people can help improve sustainability of the food system and soil functions

Globally soil quality and food security continue to decrease indicating that agriculture and the food system need to adapt. Improving connection to the soil by knowledge exchange can help achieve this. We propose a framework of three types of connections that allow the targeting of appropriate messages to different groups of people. Direct connection by, for example, handling soil develops soil awareness for management that can be fostered by farmers joining groups on soil-focused farming such as organic farming or no-till. Indirect connections between soil, food and ecosystem services can inform food choices and environmental awareness in the public and can be promoted by, for example, gardening, education and art. Temporal connection revealed from past usage of soil helps to bring awareness to policy workers of the need for the long-term preservation of soil quality for environmental conservation. The understanding of indirect and temporal connections can be helped by comparing them with the operations of the networks of soil organisms and porosity that sustain soil fertility and soil functions.     

Recovery approach affects soil quality in the water level fluctuation zone of the Three Gorges Reservoir,China: implications for revegetation

Plants in the water level fluctuation zone of the Three Gorges Reservoir Region disappeared due to winter-flooding and prolonged inundation. Revegetation (plantation and natural recovery) have been promoted to restore and protect the riparian ecosystem in recent years. Revegetation may affect soil qualities and have broad important implications both for ecological services and soil recovery. In this study, we investigated soil properties including soil pH values, bulk density, soil organic matter (SOM), soil nutrients and heavy metals, soil microbial community structure, microbial biomass, and soil quality index under plantation and natural recovery in the Three Gorges Reservoir Region. Most soil properties showed significant temporal and spatial variations in both the plantation and natural recovery areas. Higher contents of SOM and NO₃-N were found in plantation area, while higher contents of soil pH values, bulk density, and total potassium were observed in the natural recovery area. However, there were no significant differences in plant richness and diversity and soil microbial community structure between the two restoration approaches. A soil quality index derived from SOM, bulk density, Zn, Cd, and Hg indicated that natural recovery areas with larger herbaceous coverage had more effective capacity for soil restoration.     

Utilization of a biosurfactant foam/nanoparticle mixture for treatment of oil pollutants in soil

Oil contamination has become a primary environmental concern due to increased exploration, production, and use. When oil enters the soil, it may attach or adsorb to soil particles and stay in the soil for an extended period, contaminating the soil and surrounding areas. Nanoparticles have been widely used for the treatment of organic pollutants in the soil. Surfactant foam has effectively been employed to remediate various soil contaminants or recover oil compounds. In this research, a mixture of biosurfactant foam/nanoparticle was utilized for remediation of oil-contaminated soil. The results demonstrated that the biosurfactant/nanoparticle mixture and nitrogen gas formed high-quality and stable foams. The foam stability depended on the foam quality, biosurfactant concentration, and nanoparticle dosage. The pressure gradient change in the soil column relied on the flowrate (N₂ gas + surfactant/nanoparticle mixture), foam quality, and biosurfactant concentration. The optimal conditions to obtain good quality and stable foams and high oil removal efficiency involved 1 vol% rhamnolipid, 1 wt% nanoparticle, and 1 mL/min flowrate. Biosurfactant foam/nanoparticle mixture was effectively used to remediate oil-contaminated soil, whereas the highest treatment efficiency was 67%, 59%, and 52% for rhamnolipid biosurfactant foam/nanoparticle, rhamnolipid biosurfactant/nanoparticle, and only rhamnolipid biosurfactant, respectively. The oil removal productivity decreased with the increase of flowrate due to the shorter contact time between the foam mixture and oil droplets. The breakthrough curves of oil pollutants in the soil column also suggested that the foam mixture’s maximum oil treatment efficiency was higher than biosurfactant/nanoparticle suspension and only biosurfactant.

     

Citrus stand ages regulate the fraction alteration of soil organic carbon under a citrus/Stropharua rugodo-annulata intercropping system in the Three Gorges Reservoir area,China

Environmental Science and Pollution Research - Soil carbon fractionation is a valuable indicator in assessing stabilization of soil organic matter and soil quality. However, limited studies have...     

Mobility of adsorbed arsenic in two calcareous soils as influenced by water extract of compost

The mobility of arsenic (As) in soil affects both the bio-toxicity of As and the groundwater quality, which in turn indirectly affects the quality of edible part of crops and human health, if the crops were irrigated with As contaminated groundwater. A vertical soil column simulates the depth of a soil profile in a real soil environment. Thus soil column experiment is much more pertinent to soil environment than a batch experiment to simulate solute movement as well as leaching through soil profile. A laboratory soil column experiment was conducted to determine the extent of As leaching from soil percolated with influent that contained organic substances. The water extract of compost (WEC) was used as the source of organic substances. The results of As breakthrough curves (BTCs) showed that less pore volumes of influents were required to reach the relative concentration ratio of 1 (C/C0=1) for the two calcareous soils treated with influent that contained WEC. The concentrations of As in the column effluents of soils percolated with 0.01M KCl in WEC were significantly higher than those percolated with 0.01M KCl with the same volumes of effluents collected. This clearly indicates that dissolved as well as deprotonated organic substances which are negatively charged have higher potential for competing the adsorption sites with As on soils, leading to increasing mobility of As in soil and associated environments. Further, it is observed that the characteristics of soil components related to As adsorption affected the adsorption as well as desorption processes and subsequent mobility of As in soil environment as influenced by organic substances.     

改良剂对Cd污染土壤中小白菜品质的影响

通过小白菜盆栽试验,以啤酒污泥、草木灰及其混合物作为土壤改良剂,以生物量、可溶性糖、维生素C和叶绿素含量为指标,研究了改良剂对小白菜品质的影响,并分析了土壤中Cd赋存形态的变化。结果表明,不同改良剂在性质和改良机制上存在差异,因此改良效果各不相同,其中啤酒污泥和草木灰的混合物的改良效果最好,其次是啤酒污泥,最后是草木灰。虽然3种改良剂均能降低小白菜茎叶中Cd含量和土壤中有效态(水溶态和可交换态)Cd含量,提高小白菜品质,但小白菜茎叶中Cd含量仍超过《食品中污染物限量》(GB 2762—2005)规定的蔬菜中Cd限量值。     

Impact of soil management and two botanical insecticides on urease and invertase activity

Yard waste compost provides an organic amendment useful for improving soil structure and nutrient status. The activities of the enzymes hydrolyzing urea (urease) and sucrose (invertase) in the rhizosphere of potato plants were determined under field conditions. Soil urease and invertase activities were monitored in compost amended soil, grass buffer strips, and in adjacent bare soils during 35 d following soil treatment. Soil urease activity was increased by application of yard waste compost compared to untreated soil which provide evidence of increased soil microbial population following application of compost. Some transitional effects on urease activities were observed following Pyrethrins and Neemix-4E application, these effects were neither drastic nor prolonged enough to be considered deleterious to the soil microorganisms and their activities important to soil fertility. No relationship was found between invertase activity and the three management practices or soil organic matter content. It is suggested that application of botanical insecticides like pyrethrins and Neemix-4E may be useful in delaying urea fertilizer mineralization to maintain N in a form less leachable, so that the duration of N availability to plants is prolonged. The present study may also provide information on urease activity as a sensitive bioindicator of soil quality that reflects the effects of land management on soil quality and may assist land managers in monitoring long-term productivity and sustainability of agricultural lands.     

土壤环境质量及其演变的影响因素

阐述了土壤环境质量的定义以及近百年来的土壤环境质量的演变，着重分析了土壤环境质量演变的诸多影响因素，并提出了土壤污染防治的对策。     

Changes in soil quality and below-ground carbon storage with conversion of traditional agricultural crop lands to bioenergy crop production

Berm-isolated (0.5 ha) plots have been used since 1995 to quantify changes in soil and water quality with conversion from agricultural to bioenergy crops. Soil quality improvements, including increases in soil carbon storage, have occurred on sites planted to woody or herbaceous species, and no-till corn compared with tilled corn or cotton. Initial increases in soil carbon occurred within the upper 10 cm of the soil profile. Soil carbon on plantings of switchgrass, no-till corn, and sweetgum with a cover crop between the rows increased over the first 3 years. Soil carbon decreased by 6% on the sweetgum plantings without a cover crop and remained lower through the fifth growing season. Overall, the greatest increases in below ground carbon storage have occurred primarily within the upper 40 cm. Former land use, growth characteristics, management practices, and soil characteristics appear to be the primary factors determining the timing, depth. and extent of changes in soil carbon storage for bioenergy and no-till crops.     

Impact of Soil Management and Two Botanical Insecticides on Urease and Invertase Activity

Yard waste compost provides an organic amendment useful for improving soil structure and nutrient status. The activities of the enzymes hydrolyzing urea (urease) and sucrose (invertase) in the rhizosphere of potato plants were determined under field conditions. Soil urease and invertase activities were monitored in compost amended soil, grass buffer strips, and in adjacent bare soils during 35 d following soil treatment. Soil urease activity was increased by application of yard waste compost compared to untreated soil which provide evidence of increased soil microbial population following application of compost. Some transitional effects on urease activities were observed following Pyrethrins and Neemix‐4E application, these effects were neither drastic nor prolonged enough to be considered deleterious to the soil microorganisms and their activities important to soil fertility. No relationship was found between invertase activity and the three management practices or soil organic matter content. It is suggested that application of botanical insecticides like pyrethrins and Neemix‐4E may be useful in delaying urea fertilizer mineralization to maintain N in a form less leachable, so that the duration of N availability to plants is prolonged. The present study may also provide information on urease activity as a sensitive bioindicator of soil quality that reflects the effects of land management on soil quality and may assist land managers in monitoring long‐term productivity and sustainability of agricultural lands.     

Long-term effects of soil heterogeneity on cadmium behaviour in soil

A deterministic model for long-term behaviour of contaminants in the rootzone is developed that includes sorption, leaching, and plant uptake. The model is applied to cadmium accumulation in a sandy soil and uptake of cadmium by barley. Sensitivity analysis showed that the sensitivity of the leaching rate to changes in soil chemical and soil physical parameters decreases as a function of time, and becomes zero when steady state is reached. In contrast, accumulation of cadmium in soil and the plant uptake rate of barley are increasingly sensitive to soil chemical and soil physical parameters as time preceeds. To analyse cadmium behaviour in a field that is heterogeneous with respect to soil physical properties, the interstitial flow velocity was assumed to be a random, lognormally distributed variate. Using Monte Carlo simulation, the average plant uptake rate appeared to be much higher in the stochastic analysis than in the deterministic approach. Steady state is reached after a very long period of time. For a lognormally distributed proton activity, causing heterogeneity with respect to the sorption capacity of the soil, the model predicted similar deviations from the deterministic approach. It is concluded that reference values for groundwater and crop quality are exceeded earlier in a heterogeneous field than in a homogenous soil profile. Moreover, when average values suggest an acceptable situation, variability of the leaching rate and the plant uptake rate can still cause exceedance of reference values in part of the field. Therefore, it is reasoned that environmental quality standards should take soil heterogeneity into account.     

宝应县土壤重金属的污染调查

以宝应县农田土壤重金属调查为依据，采用污染指数法对土壤质量进行评价，分析土壤重金属污染原因，提出防治措施。     

Ecological impacts of the N-viro biosolids land-application for wild blueberry (Vaccinium angustifolium. Ait) production in Nova Scotia

Land application of biosolids from processed sewage sludge may deteriorate soil, water, and plants. We investigated the impact of the N-Viro biosolids land-application on the quality of the soil water that moved through Orthic Humo-Ferric Podzols soil of Nova Scotia (NS) at the Wild Blueberry Research Institute, Debert, NS Canada. In addition, the response of major soilproperties and crop yield was also studied. Wild blueberry (Vaccinium angustifolium. Ait) was grown under irrigated and rainfed conditions in 2008 and 2009. Four experimental treatments including (i) NI: N-Viro irrigated, (ii) NR: N-Viro rainfed, (iii) FI: inorganic fertilizer irrigated, and (iv) FR: inorganic fertilizer rainfed (control) were replicated 4 times under randomized complete block design. Soil samples were collected at the end of each year and analyzed for changes in cation exchange capacity (CEC), soil organic matter (SOM), and pH.Soil water samples were collected four times during the study period from the suction cup lysimeters installed within and below crop root zone at 20 and 40 cm depths, respectively. The samples were analyzed for a range of water quality parameters including conductance, hardness, pH, macro- and micronutrients, and the infectious pathogens Escherichia coli (E. coli) and salmonella. Berries were harvested for fruit yield estimates. Irrigation significantly increased CEC during 2008 and the soil pH decreased from 4.93 (2008) to 4.79 (2009). There were significant influences of irrigation, fertilizer, and their interaction, in some cases, on most of the soil water quality parameters except on the infectious bacteria. No presence of E. coli or salmonella were observed in soil and water samples, reflecting the absence of these bacteria in biosolids used in this experiment. Nutrient concentration in the soil water samples collected from the four treatments were higher in the sequence NI > NR > FI > FR. The irrigation treatment had significant effect on the unripe fruit yield. We conclude that the comparable performance of N-Viro biosolids and the increasing prices of inorganic fertilizers would compel farmers to use economically available N-Viro biosolids that, coupled with the supplemental irrigation, did not deteriorate the studied soil properties, soil water quality, and the wild blueberry yield during this experiment.     

Impact of chemical oxidation on soil quality

Oxidation treatment helps to reduce the polycyclic aromatic hydrocarbon (PAH) load in contaminated soils but it may also have an effect on the soil quality. The impact of permanganate and Fenton oxidation on soil quality is investigated. Soil quality is restricted here to the potential for plant growth. Soil samples were collected from an agricultural field (S1) and a former coking plant (S4). Agricultural soil was spiked with phenanthrene (PHE) and pyrene (PYR) at two concentrations (S2: 700 mg PHE kg⁻¹, S3: 700 mg PHE kg⁻¹ and 2100 mg PYR kg⁻¹). Soils were treated with both oxidation processes, and analyzed for PAHs and a set of agronomic parameters. A plant germination and growth test was run with rye-grass on treated soils. Results showed that both treatments produced the expected reduction of PAH concentration (from 64% to 97%). Besides, a significant loss of organic C and N, and strong changes in available nutrients were observed. Permanganate treatment increased the specific surface area and the cation exchange capacity in relation to manganese dioxide precipitation, and produced a rise in pH. Fenton oxidation decreased soil pH and increased the water retention capacity. Plant growth was negatively affected by permanganate, related to lower soil permeability and aeration. Both treatments had an effect on soil properties but Fenton oxidation appeared to be more compatible with revegetation.