Lead (Pb) is a non-threshold toxin capable of inducing toxic effects at any blood level but availability of soil screening criteria for assessing potential health risks is limited. The oral bioaccessibility of Pb in 163 soil samples was attributed to sources through solubility estimation and domain identification. Samples were extracted following the Unified BARGE Method. Urban, mineralisation, peat and granite domains accounted for elevated Pb concentrations compared to rural samples. High Pb solubility explained moderate-high gastric (G) bioaccessible fractions throughout the study area. Higher maximum G concentrations were measured in urban (97.6 mg kg−1) and mineralisation (199.8 mg kg−1) domains. Higher average G concentrations occurred in mineralisation (36.4 mg kg−1) and granite (36.0 mg kg−1) domains. Findings suggest diffuse anthropogenic and widespread geogenic contamination could be capable of presenting health risks, having implications for land management decisions in jurisdictions where guidance advises these forms of pollution should not be regarded as contaminated land.

In recent decades, significant advances have been made in understanding the generation, fates and consequences of water quality pollutants in the Great Barrier Reef ecosystem. However, skepticism and lack of trust in water quality science by farming stakeholders has emerged as a significant challenge. The ongoing failures of both compulsory and particularly voluntary practices to improve land management and reduce diffuse agricultural pollution from the Great Barrier Reef catchment underlines the need for more effective communication of water quality issues at appropriate decision-making scales to landholders. Using recent Great Barrier Reef catchment experiences as examples, we highlight several emerging themes and opportunities in using technology to better communicate land use-water quality impacts and delivery of actionable knowledge to farmers, specifically supporting decision-making, behavior change, and the spatial identification of nutrient generation ‘hotspots’ in intensive agriculture catchments. We also make recommendations for co-designed monitoring-extension platforms involving farmers, governments, researchers, and related agencies, to cut across stakeholder skepticism, and achieve desired water quality and ecosystem outcomes.

To protect and improve water quality in the Great Barrier Reef, the Queensland Government's Reef 2050 Water Quality Improvement Plan targets that 90% of sugarcane, horticulture, cropping and grazing lands in priority areas be managed using best management practices for sediment, nutrient and pesticides by 2025. Progress towards this target is insufficient and variable across catchments and industries. The motivation to adopt improvements in management practices is heavily influenced by social, economic, cultural and institutional dimensions. In this paper we synthesise the literature on how these human dimensions influence decision making for land management practice and highlight where future investment could be focussed. We highlight that focussing on —1) investigating systems to support landholder decision making under climate uncertainty (risk); 2) generating a better understanding of the extent and drivers of landholder transaction cost; 3) understanding if there are competing ‘right’ ways to farm; and 4) improving understanding of the social processes, trust and power dynamics within GBR industries and what these means for practice change— could improve practice change uptake in the future.

We examined the effects of an amended mixture of three pesticides, atrazine (72.7 g), S-metolachlor (54.5 g), and permethrin (both cis and trans isomers; 11.4 g), on 10-day sediment toxicity to Hyalella azteca in a managed natural backwater wetland after a simulated agricultural runoff event. Sediment samples were collected at 10, 40, 100, 300, and 500 m from inflow 13 days prior to amendment and 1, 5, 12, 22, and 36 days post-amendment. Background pesticide concentrations ranged from <1 to 977, <1 to 119, and <1 to 2 μg kg⁻¹, for atrazine, S-metolachlor, and permethrin, respectively. Average post-amendment atrazine and S-metolachlor were 2,915–3,927 and 3–20 μg kg⁻¹, respectively at 10–40 m and 538–872 and <1 μg kg⁻¹, respectively at 300–500 m. Average post-amendment permethrin was 65–200 μg kg⁻¹ at 10–40 m and 1–10 μg kg⁻¹ at 300–500 m. H. azteca 10-day survival varied spatially and temporally up to 100 m from inflow. Animal growth, independent of survival, was reduced 40 and 100 m from inflow on day 36, showing continued sediment toxicity of up to 100 m from inflow more than 1 month after amendment. Animal survival and growth were unaffected at 300 and 500 m from inflow throughout the study period. Correlations of pesticide concentrations and H. azteca responses indicated that observed sediment toxicity was primarily from permethrin with potential additional synergistic toxicity from atrazine and methyl parathion. Study results indicate that natural backwater wetlands can be managed to ameliorate pesticide mixture 10-day sediment toxicity to H. azteca within 300 m of inflow and smaller wetlands (≤100 m) may require several months of effluent retention to mitigate effects.

Farmland abandonment, as a manifestation of the low efficiency of the rural economy, has a profound impact on the process of agricultural and rural modernization. This study uses the 2016 China Labor Force Dynamic Survey data based on 8116 samples from 104 cities, constructs the Tobit model and IV Tobit model to analyze the land abandonment quantitatively from the perspective of environmental pollution. The results show that (1) environmental pollution can significantly increase the probability and area of land abandonment, (2) there is significant regional heterogeneity in the impact of environmental pollution on land abandonment, (3) the impact of environmental pollution on land abandonment varies significantly with different family sizes and land management scales, but the land management scale is relatively more sensitive. This study provides a deeper understanding of the relationship between environmental pollution and land abandonment in China and provides a basis for formulating relevant policies to strengthen the treatment of environmental pollution to solve the dilemma of land abandonment, which is of great practical significance to sustainable development of rural economy and the guarantee of food security in China.

In this study, we simulated heterotrophic CO₂(Rh) fluxes at six European peatland sites using the ECOSSE model and compared them to estimates of Rh made from eddy covariance (EC) measurements. The sites are spread over four countries with different climates, vegetation and management. Annual Rh from the different sites ranged from 110 to 540 g C m⁻². The maximum annual Rh occurred when the water table (WT) level was between −10 and −25 cm and the air temperature was above 6.2 °C. The model successfully simulated seasonal trends for the majority of the sites. Regression relationships (r²) between the EC-derived and simulated Rh ranged from 0.28 to 0.76, and the root mean square error and relative error were small, revealing an acceptable fit. The overall relative deviation value between annual EC-derived and simulated Rh was small (−1 %) and model efficiency ranges across sites from −0.25 to +0.41. Sensitivity analysis highlighted that increasing temperature, decreasing precipitation and lowering WT depth could significantly increase Rh from soils. Thus, management which lowers the WT could significantly increase anthropogenic CO₂, so from a carbon emissions perspective, it should be avoided. The results presented here demonstrate a robust basis for further application of the ECOSSE model to assess the impacts of future land management interventions on peatland carbon emissions and to help guide best practice land management decisions.

The aim of the present study was the influence of various methods of long-term soil utilisation on the content of polycyclic aromatic hydrocarbons (PAH) in selected silty soils. Four soils were selected for the present studies, i.e.: Eutric Fluvisol originating from silty formations, Haplic Phaeozem developed from loess, Haplic Luvisol (non-uniform) developed from silt, Haplic Luvisol developed from loess. Five study sites were chosen, i.e.: apple orchards, hop gardens, fields, grasslands and natural woodland ecosystems. Samples were collected from the depth of 0-10 cm. In the samples the content of 16 PAHs was determined by means of the HPLC-UV method. The total PAHs content was at a low level. Depending on the soil and object type, the total PAHs content ranged from 72.5 to 764.0 μg·kg-¹. The pollutant level determined together with composition of individual PAHs suggested a limited anthropogenic influence relating mainly to pyrolytic processes. The total PAH content as well as the content of individual PAHs depended on agricultural land use and management. It has been shown that PAH level was influenced by environmental conditions specific for a given type of land use. In the soils in which organic carbon content differed only slightly among locations, a higher influence of the soil utilisation method on the content of individual PAHs was observed.

Over the past couple of decades, the world has witnessed a rise in greenhouse gas (GHG) emissions and rising income inequality that threatens human well-being. Addressing these challenges and ensuring sustainable development become a pressing issue for policymakers. This paper investigates the impact of GHG emissions on income inequality in Africa. The study uses a panel data set from 49 countries from 1981 to 2015 and shows that GHG emission widens income inequality. The result is robust for alternative emission indicators. A direct implication is that climate change policy should be designed to narrow income inequality. It is emphasized that mitigation actions should focus on the agriculture sector. Hence, intervention towards energy-smart agriculture, land conservation practices, exploiting the job creation potential, and strengthening value addition in the agricultural sector is decisive. Reforming agriculture reduces emission, narrows income inequality, and realizes sustainable development on the continent.

Changes in land management and climate alter vegetation dynamics; however, the factors driving vegetation changes remain elusive at multiple spatiotemporal levels. Here, we assess the drivers of changes in greenness from 2000 to 2015 in Northwest China (NW China). We used multiple stepwise linear regression (MSLR), redundancy analysis (RDA), and 12 other models to quantify the impacts of precipitation and temperature metrics, gross domestic product (GDP), population, and grazing intensity on the normalized difference vegetation index (NDVI) at three administrative levels (county, town, and village), four temporal levels (yearly, May, July, and September), two vegetation types (woodland and grassland), and at annual precipitation gradients of <200, 200–400, and >400 mm. The results suggest that NW China underwent vegetation greening from 2000 to 2015. Precipitation and temperature were the most influential factors contributing to the NDVI change. Population was the main determinant of NDVI under the precipitation gradient of <200 mm, and the effect of GDP on NDVI was moderate. On the temporal scale, annual precipitation, precipitation before the previous year, and precipitation in the current year determined the NDVI in May, July, and September, respectively, for both woodland and grassland. At multiple scales, climate change was the primary driver of vegetation change in NW China, rather than human disturbance. These findings expand our understanding on drivers of NDVI at multiple levels over a long period. Measures to manage decreasing vegetation coverage may be more effective and could be implemented sooner based on predicted climate change in drylands worldwide.

The accumulation of potential toxic elements (PTEs) in soils is usually conditioned by parental material or anthropogenic sources. To achieve correct land management and land degradation neutrality, it is necessary to spatially detect them. However, there are several areas over the world with high concentrations of PTE but without efficient maps and tools to correctly find solutions and apply control measures. The current study attempts to identify the concentrations, sources, and spatial distributions of the main PTEs such as As, Cd, Cr, Cu, Ni, Pb, and Zn in a non-explored area combining fieldwork and geostatistical analysis. In order to accomplish this goal, a total of 90 soil samples were collected in agricultural and natural areas in the Piedemonte Llanero, Colombia. The chemical analysis was conducted by acid digestion and determined through ICP-OES. Then, ordinary kriging was applied to spatially analyze the most vulnerable areas. Our results demonstrated the effectiveness of these techniques and it is noted that the agricultural areas presented the highest concentrations and represented the potential source of PTEs. On the other hand, the natural areas presented the following concentrations of PTEs Cr (17.10 mg/kg), As (2.92 mg/kg), Cu (7.57 mg/kg), Ni (8.63 mg/kg), Cd (0.17 mg/kg), Pb (8.80 mg/kg), and Zn (27.57 mg/kg) lower than agricultural soils. This information was a key first step to be presented to the policymakers and stakeholders to organize soil sustainable management plans for the Piedemonte Llanero in Colombia.