Effectiveness of Combined Biochar and Lignite with Poultry Litter on Soil Carbon Sequestration and Soil Health

Healthy soils are important to ensure satisfactory crop growth and yield. Poultry litter (PL), as an organic fertilizer, has proven to supply the soil with essential macro and micronutrients, enhance soil fertility, and improve crop productivity. Integrating this treatment has the potential to improve soil physical and biological properties by increasing soil carbon, C. However, rapid decomposition and mineralization of PL, particularly in the hot and humid southeastern U.S., resulted in losing C and reduced its effect on soil health. Biochar and lignite have been proposed to stabilize and mitigate C loss through application of fresh manure. However, their combined effects with PL on C sequestration and soil health components are limited. A field experiment was conducted on Leeper silty clay loam soil from 2017 to 2020 to evaluate the combined effect on soil properties when applying biochar and lignite with PL to cotton (Gossypium hirsutum L.). The experimental design was a randomized complete block involving nine treatments replicated three times. Treatments included PL and inorganic nitrogen, N, fertilizer with or without biochar and lignite, and an unfertilized control. Application rates were 6.7 Mgkg⋅ha−1 for PL, 6.7 Mgkg⋅ha−1 for biochar and lignite and 134 kg⋅ha−1 for inorganic N fertilizer. Integration of PL and inorganic fertilizer with biochar and lignite, resulted in greater soil infiltration, aggregate stability, plant available water, reduced bulk density and penetration resistance as compared to the sole applications of PL and inorganic fertilizer.

Effect of Fertilization on Tomato Bacterial Wilt Biocontrolling and Soil Health Restoration Using FAME Analysis

The effect of applying biological organic fertilizer(BOF)on bacterial wilt incidence of tomato and soil microbial community under continuous cropping was studied. The results showed that all the tomatoes were infected by bacterial wilt in the control. The infection rates of tomatoes in the treatments with un-composted BOF and decomposed BOF were 55 and 50% respectively. Fatty acid methyl esters(FAME)analysis indicated soil microbial community changed sensitively after applying BOF. Soil FAME total content, relative fungi content and ratio of fungi to bacteria were significantly increased in both BOF treatments. The soil odd-number fatty acid proportion changed after applying BOF, aC15 : 0, iC17 : 0 decreased, while cyC17 : 0 increased in soil odd-number fatty acid proportion. BOF application would strengthen soil health and disease suppression. The content of C16 : 1 11c in soil microbial community was obviously increased after decomposed BOF application. It indicated that the growth of AM fungi could be enhanced with decomposed BOF application. FAME microbial biomarkers could be used for an indicator of soil health and disease suppression. Odd-number fatty acid proportion was a sensitive indicator of the effect of applying un-composted and decomposed BOF respectively on soil health regulating.

In-Field Corn Residue Management for Bioenergy Use: Potential Effects on Selected Soil Health Parameters

In the U.S. biofuel industry is using corn (Zea mays L.) residue mix (CRM) consisting of corncob and stover for cellulosic ethanol and biogas production. The field storage method left different depths of CRM on the field after its removal, where negative effects on plant growth were observed. The objective of this study is to evaluate the CRM effect on selected soil health indicators. The field study conducted with four different depths of CRM, two tillage systems (no-till (NT) and chisel plow (CP), and three nitrogen (N) rates (0, 180, and 270 kg⋅N⋅ha−1) in a randomized complete block design with split-split arrangements in three replications in a continuous corn system from 2010 to 2012 at the Agronomy Research Farm at Iowa State University. The findings of this study showed a negative effect on soil organic carbon (SOC) change across all treatments at 0 - 15 cm (−0.35 to −0.03 Mg⋅ha−1⋅yr−1), while at 15 - 30 cm there was an increase in SOC rate (0.13 to 0.40 Mg⋅ha−1⋅yr−1) after 2-yr. In addition, soil aggregate-associated C of macro-aggregates decreased by 8%, while micro-aggregates increased by 2%. Soil microbial biomass carbon (MBC) across tillage and N rates for 2.5 & 7.5 CRM treatments increased by 14% in June to July 2011, while in 2012 increased by 9%. However, at the 15 cm soil depth, soil bulk density (ρb), soil penetration resistance (SPR), and soil pH showed no significant differences among CRM treatments. The findings of this study showed that in-field CRM management can affect certain soil health parameters in the short term.

Aluminum Soil Chemistry: Influence on Soil Health and Forest Ecosystem Productivity

Soil aluminum phytotoxicity has been a major research area since the inception of modern soil science. Acid soils, which typically manifest plant aluminum toxicity, are frequently dedicated to food production, thus yield and quality reductions influence food security. This manuscript reviews our modern understanding of 1) soil aluminum hydrolysis and polymerization, 2) aluminum complexation with inorganic and organic anions, 3) aluminum interference with vital plant physiological processes, 4) aluminum and forest ecosystem productivity, and 5) demonstrates the software simulation of aluminum reactivity and its role in predicting soil behavior. The manuscript also provides a perspective for future soil-aluminum research critical to maintaining food security and food quality.

Current State and Development of the Soil Health Index in Localities with Various Soil-Climatic Conditions in the Slovak Republic

The aim of the study was to assess the current state and development of the Soil Health Index (SHI) at 13 localities with various soil-ecological conditions in the Slovak Republic. The SHI was developed using a minimum soil data set, physical and chemical soil parameters in combination with environmental parameters (land use, gradients). The SHI is one numerical value accumulates information about the state of soil health and its ability to provide soil functions and thus ecosystems in the optimal range. The highest SHI values were determined at model localities used as arable land (Haplic Chernozem, Fluvisol) located in a warm climate at altitudes up to 200 meters above sea level. Ecosystems with very low and low value are mostly grasslands with mildly cold climate (Cambisol) and considerable slope, agroecosystem on low organic matter (Arenosol). Arable ecosystem SHI is also reduced in areas of geochemical anomalies and areas with anthropogenic load, where there is a higher content of risk elements. The SHI changes are mainly the result of changes in dynamic indicators such as soil response and soil bulk density.

Utilization of Compost as a Soil Amendment to Increase Soil Health and to Improve Crop Yields

Compost amendments have remarkable potential for improving soil structure, porosity and water holding capacity. Soil health is the ability to function as a living system, to sustain plant and animal productivity, to enhance water and air quality, and to promote plant and animal health. Soil health can be estimated by measuring the total living microbial biomass, retained carbon, odor, and texture. Poor or deteriorating soil health is threatening food security. The potential for compost to reverse these negative trends is transformative if means and methods for large scale composting and compost amendments can be developed. A field-scale compost soil amendment project was implemented in Rapid City, South Dakota. The compost was added to a soil plot at 5 wt% and 10 wt% and the results were compared with an adjacent untreated plot without any compost addition. Measurements of soil health characteristics indicate that compost amendments improve soil health, crop yields, and soil water content. Treating soils with compost has the potential to reverse global deteriorating soil health.

The Role of Cover Crops towards Sustainable Soil Health and Agriculture—A Review Paper

Cover crops are the plants which are grown to improve soil fertility, prevent soil erosion, enrichment and protection of soil, and enhance nutrient and water availability, and quality of soil. Cover crops provide several benefits to soils used for agriculture production. Cover crops are helpful in increasing and sustaining microbial biodiversity in soils. We summarized the effect of several cover crops in soil properties such as soil moisture content, soil microbial activities, soil carbon sequestration, nitrate leaching, soil water, and soil health. Selection of cover crops usually depends on the primary benefits which are provided by cover crops. Other factors may also include weather conditions, time of sowing, either legume or non-legume and timing and method of killing of a cover crop. In recent times, cover crops are also used for mitigating climate change, suppressing weeds in crops and increasing exchangeable nutrients such as Mg2+ and K+. Cover crops are also found to be economical in long-term experiment studies. Although some limitations always come with several benefits. Cover crops have some problems including the method of killing, host for pathogens, regeneration, and not immediate benefits of using them. Despite the few limitations, cover crops improve the overall health of the soil and provide a sustainable environment for the main crops.

Advancements in assessing soil health through functional traits and energy flow analysis of soil

We examined the development of soil nematodes ecological indices from the perspective off unctionaltraits.We found that soil nematode energy flow analyses based on multiple functional traits quantify the dynamics of energy flow across multipletrophic levels to provide a more comprehensive perspective.We conducted comparative analyses of the sensitivities of NMF and energy flow to verify that the energy flow analyses are more sensitive and have greater potential to reveal soil health and ecosystem function.Future in-depth studies of functional traits and energy flow analysis can help us achieve informed soil management practices,sustainable agriculture,andhealthiersoilecosystems.nignerEauc Tess CT Nematode ecological index based on functional traits:MI El,S,BI,C1 NMF Bongen.1990 Ferrisetal,2001 Ferris,2010 energs low analysis of soil nematodes Compare thecological index(NMf)and Bacterivores(Ba)Functional traits Energy flux Fungihores(Fn)rahn Soilnematodes latitude Lindicator Plant-parasites(PP)PF Energflus Soilhealth Omnivores-predators(oP)latitude Energy flow analysis of soil nematodes:By quantifying energy fux among trophic groups Barbes et al.,2014,2018 This paper examines the development of ecological indices for soil nematodes from the perspective of functional traits.It emphasizes the increasing significance of integrating multiple functional traits to achieve a more accurate assessment of soil health.Ecological indices based on life history strategies,feeding habits,and body size provide useful tools for assessing soil health.However,these indices do not fully capture the dynamics ofenergyflow across multiple-trophic levels inthesoil foodweb,which is critical fora deeperunderstanding of the intrinsic properties of soil health.By combining functional traits such as functional group,body size,feeding preference and metabolic rate,nematode energy flow analyses provide a more comprehensive perspective.This approach establishes a direct correlation between changes in the morphology,physiology,and metabolism of soil organisms and alterations in their habitat environment.We conducted comparative analyses of the sensitivity of nematode metabolic footprints and energy flow to latitudinal variation using a nematode dataset from the northeastern black soil region in China.The findings suggest that energy flow analyses are more sensitive to latitude and have greater potential to reveal soil health and ecosystem function.Therefore,future research should prioritize the development of automated and efficient methods for analyzing nematode traits.This will enhance the application of energy flow analyses in nematode food webs and support the development of sustainable soil management and agriculturalpractices.

Soil health and root-zone enrichment characteristics between paired grassland and cropland fields in the southeastern United States

Background:Soil organic C and N data from privately managed pastures in the southeastern United States are relatively scant.Methods:A paired-farm approach was deployed to determine how a variety of soil health parameters related to nutrient and water cycling might be altered under grazed,botanically diverse perennial pastures compared with annual monoculture croplands in three Major Land Resource Areas of the southeastern United States.Results:Soil stability index averaged 0.64 and 0.91mm mm^(-1) under cropland and grazed pasture,respectively,suggesting that pastures had a more stable soil surface that was resistant to erosion and allowed rapid water infiltration.Surface-soil organic C and N fractions(i.e.,total,particulate,and mineralizable fractions at 0-10 cm depth)were greater under pasture than under cropland.Across locations,root-zone enrichments(0-30 cm depth)of organic C and N fractions were greater under pasture than under cropland.Within locations,root-zone enrichment of total soil N was greater(p<0.05)under pasture than under cropland in the Blue Ridge(2.87 vs.1.10 MgN ha^(-1),respectively)and the Piedmont(2.80 vs.2.10 MgNha^(-1)),but not in the Blackland Prairie(2.40 vs.2.12 MgNha^(-1)).Conclusions:This study provides evidence that rotationally grazed,perennial grasslands can store more soil organic C and N and improve soil surface stability conditions compared with neighboring croplands producing commodity feed grains for feedlot finishing.

A review of soil nematodes as biological indicators for the assessment of soil health

Healthy soils are essential for sustainableagricultural development and soil health requires carefulassessment with increasing societal concern over envir-onmentally friendly agricultural development. Soil healthis the capacity of soil to function within ecologicalboundaries to sustain productivity, maintain environmentalquality, and promote plant and animal health. Physical,chemical and biological indicators are used to evaluate soilhealth;the biological indicators include microbes, proto-zoa and metazoa. Nematodes are the most abundantmetazoa and they vary in their sensitivity to pollutants andenvironmental disturbance. Soil nematode communitiesare useful biological indicators of soil health, withcommunity characteristics such as abundance, diversity,community structure and metabolic footprint all closelycorrelated with the soil environment. The community size,complexity and structure reflect the condition of the soil.Both free-living and plant parasitic nematodes are effec-tive ecological indicators, contributing to nutrient cyclingand having important roles as primary, secondary andtertiary consumers in food webs. Tillage inversion,cropping patterns and nutrient management may havestrong effects on soil nematodes, with changes in soilnematode communities reflecting soil disturbance. Somefree-living nematodes serve as biological models to testsoil condition in the laboratory and because of theseadvantages soil nematodes are increasingly being used asbiological indicators of soil health.

New approaches for evaluation of soil health, sensitivity and resistance to degradation

Assessment of soil health requires complexevaluation of properties and functions responsible for abroad range of ecosystem services. Numerous soil qualityindices (SQI) have been suggested for the evaluation ofspecific groups of soil functions, but comparison of variousSQI is impossible because they are based on a combinationof specific soil properties. To avoid this problem, wesuggest an SQI-area approach based on the comparison ofthe areas on a radar diagram of a combination of chemical,biological and physical properties. The new approach isindependent of the SQI principle and allows rapid andsimple comparison of parameter groups and soils. Anotherapproach analyzing the resistance and sensitivity ofproperties to degradation is suggested for a detailedevaluation of soil health. The resistance and sensitivityof soil properties are determined through comparison withthe decrease of soil organic carbon (SOC) as a universalparameter responsible for many functions. The SQI-areaand resistance/sensitivity approaches were tested based on quences after the ab and on ment of agricultural soils. Both the SQI-area and the resistance/sensitivity approaches areuseful for basic and applied research, and for decisionmakersto evaluate land-use practices and measure thedegree of soil degradation.

A soil quality index for subtropical sandy soils under different Eucalyptus harvest residue managements

Eucalyptus harvest residues are attractive energy production resources for the forestry industry.However,their removal can have adverse impacts on soil quality and forest productivity,especially in sandy soils.In this study,we assessed the effects of Eucalyptus harvest residue managements with variable intensity on forest productivity and on physical,chemical,and biological indicators of the soil quality.The experiment was conducted in a Quartzipsamment(33 g kg-1clay)planted with Eucalyptus saligna in Barra do Ribeiro in southern Brazil.Before the Eucalyptus was planted,residues from the previous rotation were subjected to five different management treatments:(1)FRM,in which all forest residues(bark,branches,leaves,and litter)were allowed to remain on the soil and only trunk wood was removed;(2)FRMB,in which was identical to FRM except that bark was also removed;(3)FRMBr,in which only trunk wood and branches were removed;(4)FRR,which involved removing all types of residues(bark,branches,leaves,and litter);and,(5)FRRs,in which all forest residues from the previous rotation were removed,and leaves and branches from the new plantation were prevented from falling onto the soil surface using a shade net.Six years after planting,soil samples were collected at four different depths(0-2.5,2.5-5,5-10,and 10-20 cm)to determine 17 soil chemical,physical,and biological indicators.The results were combined into a soil quality index(SQI)using the principal component analysis approach.The SQI reduced by 30%,in the 0-20 cm layer,due to removal of harvest residues from the previous rotation,and collection of litter before it falls on the ground.The main drivers of SQI reduction were the principal components associated with soil organic matter and biological activity.Furthermore,the SQI was positively linearly related to tree height at P<0.01 and to tree diameter at breast height at P=0.07.The adverse impact on soil quality and forest productivity in our study indicates that removal of Eucalyptus harvest residues from sandy soils should be avoided.

Crop productivity,soil health,and energy dynamics of Indian Himalayan intensified organic maize-based systems

The sustainability of prevailing maize-fallow system in rainfed ecosystems of the Eastern Himalayan region(EHR)of India is often questioned due to poor economic return and negative impact on soil health.Hence,the six cropping systems,maize-fallow(M-F),maize t cowpea-rapeseed(M t C-Rs),maize t cowpea-buckwheat(M t C-Bw),maize t cowpea-barley(M t CeB),maize t cowpea-garden pea(M t C-GP)and maize t cowpeaerajmash(M t C-R)in the main plot and three soil moisture conservation measures,no-mulch(NM),maize stover mulch(MSM)and maize stover t weed biomass mulch(MSM t WBM)in sub-plot were evaluated for four consecutive years(2014-18)at a Research Farm in fixed plot fashion.Results indicated that cowpea co-culture with maize and inclusion of winter crop increased maize yield by 6.2e23.5%over M-F.Among the systems,the M t C-GP recorded the highest crop productivity.The residual effect of MSM t WBM increased maize grain yield by 19.1%over NM.Cultivation of maize t cowpea-winter crops significantly improved the available N(3.2e12.9%),P(3.6 e12.7%),K(1.9e26.3%),organic carbon(9.2e16.8%),microbial biomass carbon-MBC(15.2e43.9%)and dehydrogenases-DHA(17.2e42.3%)in soil at 0e15 cm depth as compared to M-F.The M t C-GP also recorded maximum net return(US$2460 ha1),benefit:cost(B:C)ratio(2.86)and energy use efficiency(7.9%).The MSM t WBM recorded higher net return(US$1680 ha1)and B:C ratio(2.46)over NM.Hence,cowpea t maize-garden pea(M t C-GP)along with the application of MSM t WBM is a sustainable production practice to intensify the organically managed maize-fallow system in rainfed regions of the EHR of India and other similar ecosystems.

Restoring soil health to reduce irrigation demand and buffer the impacts of drought

Irrigation consumes three quarters of globalwater withdrawals each year. Strategies are needed toreduce irrigationwater use, including increasingtheefficiency of transfer methods and field application.Comprehensive restoration of soil health, specificallythrough organic matter amendments, can substantiallyreduce irrigation demand and increase crop yield. Aprogram to restore severely degraded and desertified soilsby incorporating coarse woodchips into the soil success-fully increased rainfall capture and elevated soil moisturefor several weeks between rainfall events at both Ningxia,north-west China and North Dakota, USA. With additionof fertilizer, woodchip incorporation further increasedgrowth of wheat and alfalfa. Comprehensive soil healthassessment of remnant grasslands was used to developtarget reference soil profiles by which to guide restorationefforts. Given that most agricultural soils are degraded tosome degree, soil health restoration can provide a powerfulstrategy toward achieving global food and water security.

Evaluation of Cobalt Application Combined with Gypsum and Compost as a Regulator of Cabbage Plant Tolerance to Soil Salinity

In response to the global food crisis and the imperative to address soil degradation, the international agricultural policy is actively working to alleviate the adverse impacts of soil salinity. As part of this initiative, a field trial spanning two consecutive seasons (2019/20-2020/21) was conducted under saline conditions. The primary objective was to evaluate the influence of various compost sources, including vermicompost at a rate of 0.5 ton·fed-1 and plant residues compost at a rate of 5.0 ton·fed-1, as main plots. Subplots were established by applying agricultural gypsum, both in the presence and absence of gypsum requirements. Additionally, sub-subplots were created by externally applying cobalt at a rate of 10.0 mg·L-1, with one sub-subplot receiving foliar cobalt application and the other not. The trial sought to assess the growth performance, chemical composition, enzymatic antioxidants, yield, and quality of cabbage plants (Brassica oleracea var. capitata L.) cultivated in saline soil. According to the findings, cabbage plants exhibited the most favorable response in terms of plant height, chlorophyll content, carotene levels, leaf area, nitrogen (N), phosphorus (P), potassium (K), head yield, vitamin C, and total dissolved solids (TDS) when treated with vermicompost, followed by plant compost. Conversely, plants grown without compost exhibited the least improvement in performance. Cabbage treated with agricultural gypsum requirements showed better performance than those without gypsum amendment. Moreover, plants subjected to cobalt spray demonstrated the highest growth, yield, and quality parameters compared to those without cobalt foliar application. In contrast, the control group (plants without the studied treatments) displayed the highest levels of enzymatic antioxidants, specifically catalase and peroxidase. This indicates that soil salinity stress led to an increase in catalase and peroxidase production in cabbage plants as a defense against the harmful impact of reactive oxygen species (ROS) resulting from soil salinity stress. The applied treatments (compost, gypsum, and cobalt) led to a reduction in the cabbage plant’s inherent production of catalase and peroxidase. Generally, the combined treatment of vermicompost × gypsum requirements × cobalt proved effective in mitigating the detrimental effects of soil salinity on cabbage plants. These findings hold significance for farmers and policymakers aiming to enhance agricultural productivity in regions affected by soil salinity. Additionally, further research can explore the long-term effects of these treatments on soil health and crop sustainability.

Plant microbiomes and their role in plant health

Microorganisms are integral inhabitants of plants,playing a crucial role in plant growth,development,and health.The composition and diversity of microorganisms in plants can be influenced by several factors,including environmental factors such as soil type,temperature,and water availability.The plant microbiome serves essential functions,including nutrient acquisition,disease resistance,and stress tolerance,achieved through complex interactions between microorganisms and plants.Understanding these interactions and the impact of environmental factors can provide valuable insights into developing sustainable agricultural practices.The use of plant microbiomes in agriculture has the potential to improve crop yield,reduce fertilizer and pesticide use,and enhance soil health and sustainability,but scaling up these technologies poses several challenges.The potential benefits of using plant microbiomes in agriculture are significant and could revolutionize the industry.However,scaling up these technologies presents several challenges that require further research and innovation.In conclusion,studying plant microbiomes has the potential to bring about positive impacts for farmers,consumers,and the environment.

Quantitative Assessment of Soil Health Under Different Planting Patterns and Soil Types

Soil health assessment is an important step toward understanding the potential effects of agricultural practices on crop yield, quality and human health. The objectives of this study were to select a minimum data set for soil health evaluation from the physical, chemical and biological properties and environmental pollution characteristics of agricultural soil and to develop a soil health diagnosis model for determining the soil health status under different planting patterns and soil types in Chongming Island of Shanghai, China. The results showed that the majority of the farmland soils in Chongming Island were in poor soil health condition, accounting for 48.9% of the survey samples, followed by the medium healthy soil, accounting for 32.2% of the survey samples and mainly distributed in the central and mid-eastern regions of the island. The indicators of pH, total organic carbon, microbial biomass carbon and Cd exerted less influence on soil health, while the soil salinization and nitrate accumulation under a greenhouse cropping pattern and phosphate fertilizer shortage in the paddy field had limited the development of soil health. Dichlorodiphenyltrichloroethanes, hexachlorocyclohexanes and Hg contributed less to soil health index (SHI) and showed no significant difference among paddy field, greenhouse and open-air vegetable/watermelon fields. The difference of the SHI of the three soil types was significant at P = 0.05. The paddy soil had the highest SHI values, followed by the gray alluvial soil, and the coastal saline soil was in a poor soil health condition, indicating a need to plant some salt-tolerant crops to effectively improve soil quality.

Modeling of forest soil and litter health using disturbance and landscape heterogeneity indicators in northern Iran

This paper focuses on the indicators of soil and litter health, disturbance, and landscape heterogeneity as a tool for prediction of ecosystem sustainability in the northern forests of Iran. The study area was divided into spatial homogenous sites using slope, aspect, and soil humidity classes. Then a range of sites along the disturbance gradient was selected for sampling. Chemical and physical indicators of soil and litter health were measured at random points within these sites. Structural equation modeling(SEM) was applied to link six constructs of landscape heterogeneity, three constructs of disturbance(harvest, livestock, and human accessibility), and soil and litter health. The results showed that with decreasing accessibility, the total N and organic matter content of soil increased and effective bulk density decreased. Harvesting activities increased soil organic matter. Therefore, it is concluded that disturbances through harvesting and accessibility inversely affect the soil health. Unexpectedly, it was found that the litter total C and C:N ratio improved with an increase in the harvest and accessibility disturbances, whereas litter bulk density decreased. Investigation of tree composition revealed that in the climax communities, which are normally affected more by harvesting activities, some species like Fagus orientalis Lipsky with low decomposition rate are dominant. The research results showed that changes in disturbance intensity are reflected in litter and soil indicators, whereas the SEM indicated that landscape heterogeneity has a moderator effect on the disturbance to both litter and soil paths.

A land use-based spatial analysis method for human health risk assessment of heavy metals in soil and its application in Zhuzhou City, Hunan Province, China

A land use- and geographical information system-based framework was presented for potential human health risk analysis using soil sampling data obtained in Zhuzhou City, Hunan Province, China. The results show that heavy metal content in soil significantly differs among different land use types. In total, 8.3% of the study area has a hazard index(HI) above the threshold of 1.0. High HIs are recorded mainly for industrial areas. Arsenic((29)87%) and the soil ingestion pathway(about 76%) contribute most to the HI. The mean standardized error and root-mean-square standardized error data indicate that the land use-based simulation method provides more accurate estimates than the classic method, which applies only geostatistical analysis to entire study area and disregards land use information. The findings not only highlight the significance of industrial land use, arsenic and the soil ingestion exposure pathway, but also indicate that evaluating different land use-types can spatially identify areas of greater concern for human health and better identify health risks.

Cadmium in agricultural soils,vegetables and rice and potential health risk in vicinity of Dabaoshan Mine in Shaoguan,China

Soil cadmium(Cd)contamination resulted from mining and smelting is a major environmental concern,and health risk associated with Cd exposure to multi-media through muti-pathway is increasing.Cd concentrations in soils,vegetables and paddy rice were investigated,and potential non-carcinogenic and carcinogenic health risks exposure to Cd were estimated at six villages around the Dabaoshan Mine,South China.A total of 87 soil samples were found to exceed the China's maximum permission level(MPL)for Cd,while the highest value of 4.42 mg/kg was found near irrigation ditch associated with Hengshi River in Xinyi(XY)Village.Cd contents in vegetables and rice exceeded the maximum permissible concentration by more than five times in every village.Cadmium accumulation in plants is in the order of celery>lactuca sativa L>Chinese cabbage>Romaine lettuce>asparagus lettuce>mustard>cabbage mustard>cabbage.The mean hazard quotient(HQ)of all villages is in the range of [5.29,25.75],and the mean values of cancer risk for investigated areas are more than 10 times greater than the USEPA(2009)threshold limit value of 10-4.Moreover,human non-carcinogenic and carcinogenic risks are mainly attributable to paddy rice intake,followed by vegetables intake,soil ingestion,inhalation,and dermal contact.The results indicate that Cd has a huge potential risk on human health for the local residents.