Soil and plants store around 5% of the world’s carbon, but carbon storage in some soils is in decline. Recent research has found that climate change accounted for 9–22% of carbon declines in organic soils in semi-natural habitats throughout England and Wales from 1978–2003. The researchers say monitoring soils rich in carbon should be a priority to ensure that more carbon is not released to reinforce climate change.

Huge amounts of soil carbon have been discovered up to 1 metre below grassland in a recent UK study. Yet most carbon inventories do not assess soil deeper than 30cm. Furthermore, this research suggests that intensive management of grassland, involving high rates of fertiliser use and livestock grazing, may deplete carbon at these depths.

Most emissions of nitrous oxide (N2O) are linked to the use of nitrogen (N) fertiliser in agriculture, highlighting a need for agricultural management practices that reduce emissions while maintaining agronomic productivity. A new study has assessed the long-term impact of conventional tillage (CT — where soil is prepared for agriculture via mechanical agitation) and no-tillage (NT) systems on soil N2O emissions and crop productivity in rain-fed Mediterranean conditions. The findings show that, over a period of 18 years, mean yield-scaled (i.e. per unit grain yield) soil N2O emissions (YSNE) were 2.8 to 3.3 times lower under NT than CT. The researchers therefore recommend NT as a suitable strategy by which to balance agricultural productivity with lower soil N2O emissions in rain-fed Mediterranean agroecosystems.

Adding compost to compacted urban soils can provide a lasting effect that aids tree growth, new research indicates. Urban soils improved with added organic material are less compacted after five years compared with soils that have not been treated with organic composts, the study suggests.

How best to integrate the ecosystem services concept into regional planning? A recent study provides a practical example for an area in Germany that is faced with an increased risk of soil erosion under climate change. Researchers used a decision-support system incorporating ecosystem services to show that measures to reduce soil losses could also support a number of other services.

Monitored natural attenuation (MNA) is a long-term, ‘hands-off’ approach to cleaning up contaminated land. New research has surveyed the current development of MNA in Europe and demonstrates a clear need for practitioners to systematically collect and learn from each other’s experiences with this form of brownfield remediation.

A new review of the potential uses of visual soil evaluation (VSE) shows how this tool can be used to indicate risks of erosion, compaction, greenhouse gas emission or storage and surface-water run-off. Assessing soils in this way is not only useful for agriculture, but has implications for the wider environment, due to the vital role that soil plays in the provision of ecosystem services, for example as a habitat for biodiversity and as a carbon sink.

In-depth soil information is increasingly required to achieve an array of environmental and economic goals. In particular, accurate estimates of soil carbon stocks are necessary to guide land-management practices and climate- related policymaking. To help meet this need, Australian scientists have developed a new sensing method to analyse cylindrical soil samples (soil cores), known as the Soil Condition ANalysis System (SCANS). By integrating a novel automated soil- core sensing system (CSS) with advanced statistical analytics and modelling, the SCANS provides a level of detail that is difficult to achieve with existing alternatives. SCANS is not only rapid, accurate and inexpensive1, but is likely to be a useful tool for farmers, land managers and policymakers, as the improved assessment of soil functions, structures and carbon stocks will facilitate more informed, sustainable decision-making.

Soils play a vital role in the Earth's life-support system, yet their importance and value to society is not always recognised. A recent study suggests that incorporating soils into a National Capital and Ecosystem Services framework will raise the profile of soils and enable soils to be more easily integrated into policy decisions.

A new analysis of temperate forests has estimated that, on average, tree-felling and the removal of tree biomass reduces carbon levels in the soil by 8 per cent. The reduction is greatest in the forest floor layer where about 30 per cent of carbon is lost.

Fire frequency is changing globally, yet it is unclear how such changes affect soil carbon and nitrogen storage, and, in turn, impact on ecosystem productivity. A study was conducted to evaluate how increased fire frequency drives changes in soil carbon and nitrogen over multiple decades. Data from 48 sites that have experienced altered fire frequency were analysed, spanning up to 65 years. The meta-analysis found that frequently burned sites experienced a significant decline in surface soil carbon and nitrogen over time — on average having 36% less carbon and 38% less nitrogen, after 64 years, than sites that were protected from fire. The researchers also observed comparable changes in an independent field dataset and in dynamic model simulations of global vegetation. The results indicate that future changes in fire frequency may lead to long-term changes in the amount of carbon and nitrogen stored in soils, especially in savanna grasslands and broadleaf forests. This has implications for the global carbon cycle and for ecosystem productivity and should, therefore, be considered in the design and implementation of relevant policy instruments.

Forest root systems increase soil strength and stability, thus protecting mountainous regions against gravitational natural hazards, such as landslides. However, tree roots are affected by factors such as soil properties, climate and disturbances, such as timber-harvesting or wildfire — and, as a result, a forest’s stabilising effect can vary greatly. This study of fire-disturbed beech forests explores how this effect changes over time. The results reveal that forests which have suffered moderate and severe wildfires completely lose their protective function within 15 years, placing those regions at high risk of landslide for up to 50 years after the fires.

Effective regulation of genetically modified organisms (GMOs) calls for monitoring of the potential environmental risks. This study explored whether the German permanent soil monitoring programme could be a useful tool for this purpose. The researchers say the programme has potential to monitor the effects of GMOs on local soil communities, but that adaptations would be necessary.

Following rapid urbanisation, management of contaminated soil has become a political priority in China. In this study, researchers reviewed the current system in China as compared to Europe and provide recommendations for the sustainable management of soil.

Soil stabilisation and the process of strengthening the physical properties of soil is fundamental to the construction process of infrastructure such as roads, runways and earth dams. Many chemical additives currently used in soil stabilisation are associated with adverse environmental effects and this study examines the use of biopolymers, such as xanthan gum and guar gum, as more sustainable alternatives. The researchers have run a series of laboratory experiments to evaluate the viability of these two types of biopolymers for use as additives for collapsible soil stabilisation, and found that both could be used in place of conventional additives to improve soil strength, permeability and collapse potential.

A new review from Romanian researchers has summarised current and emerging methods for cleaning up contaminated land and water. It highlights the need for more consistent testing, reporting and evaluation of different remediation techniques.

Farmers have collaborated with scientists in France to evaluate agri-environmental measures that reduce soil erosion and surface water pollution at a catchment level. The exercise helped the farmers understand the benefits of the measures and provides an example of how policymakers could engage with stakeholders under the Water Framework Directive (WFD).

Soil conditions play a crucial role in determining water runoff and retention in forested sites, according to new research. Soil characteristics, such as compaction, play a greater role than forest type in determining water dynamics.

Food security is being threatened by loss of soil nutrients that are essential for the high yield of crops. A recent study outlines strategies to ensure the sustainable production of food through a holistic approach to soil nutrient management.

Small, artificial wetlands can reduce river pollution by trapping soil and nutrients swept off agricultural land by rainfall, a recent study finds. The researchers recommend that they are used as a back-up option to soil management measures also designed to reduce runoff into rivers.

Small field wetlands are a simple and effective way to reduce soil erosion and nutrient pollution, recent research suggests. The authors adapted Norwegian designs for the UK environment and created a series of small rectangular lakes on the edges of agricultural fields. After three years, the wetlands had prevented tonnes of soil from leaving the land, and helped alleviate some of the nutrient run-off that would have affected neighbouring waterways.

Worsening soil erosion in north-western Europe may be the result of a switch from traditional dairy farming to cash crops. However, even if all dairy farming ceased, reductions in runoff of up to 76% could be achieved if best agricultural practices are employed, at a cost of approximately €45 per hectare for the first three years, new research from the Austreberthe watershed in France suggests.

Comprehensive data analysed in a new study show how extensive rainfall can erode soils across the EU and Switzerland, revealing that Mediterranean regions have the highest risk for erosive events and floods. The resulting dataset can also be used for disaster planning and relief.

Straw from previous harvests can be used to help increase crop yields and improve the efficiency of water use in arid regions, finds a new study from China. By testing different techniques to improve water efficiency, the researchers found that the most effective method involved using straw to cover the soil when growing maize and wheat together in the same growing season.

Soil erosion in Italy could be reduced by 43% if Good Agricultural and Environmental Conditions (GAEC) were fully adopted, a recent study has found. Reducing soil erosion would also increase soil organic carbon stocks, particularly on cultivated sloping land.

This study paves the way for better projections of the impact of climate change on plants, including agricultural crops and carbon drawdown. The research shows how an equation used in climate models to represent soil moisture levels is responsible for major variations in estimates of the carbon cycle.

Converting grassland to arable land can reduce the diversity of nematodes, predatory mites, earthworms and enchytraeid worms in the soil, according to a study by Dutch researchers. However, they found that restoring arable land to grassland did not fully restore the diversity of these four groups during the course of the four-year study.

Little is known about the organisms that live within soil, although they play a vital role in the biological processes that support life on Earth. In a recent study, researchers calculated the relative risk of pressures caused by human activity on soil biodiversity in the EU, showing that intensive land use has the greatest impact.

The drying of soils under global warming could disrupt the balance of nutrients in large areas of the Earth's land surface, according to new research. The study focused on ‘drylands' – arid areas with low levels of rainfall – which support over 38%% of the world's population. Such nutrient imbalances could diminish the provision of ecosystem services, such as food production and carbon storage, the researchers say.

Increased plant biodiversity improves grassland soil quality by boosting its nitrogen levels, even in the absence of nitrogen-fixing plants, recent research has found. Previous research has shown that grasslands with higher biodiversity had higher levels of carbon and nitrogen. However, in the case of nitrogen it has been suggested that this was purely a result of increased numbers of nitrogen-fixing legumes, such as clover. This study was the first to show that, even without legumes, increased numbers of grassland species increased both carbon and nitrogen soil stocks.

Increased soil biodiversity can reduce nitrogen pollution, improve nutrient uptake by plants and even increase crop yields, new research suggests. The two-year study found that levels of nitrogen leaching from soil with an abundant soil life were nearly 25% lower than for soil with a reduced level of soil life. Practices which enhance soil biodiversity such as reduced tilling, crop rotation and organic farming may therefore help reduce the environmental impacts of fertilisers and improve agricultural sustainability, the researchers say.

The biodiversity and abundance of arbuscular mycorrhizal fungi — important soil organisms that can help plants to capture nutrients — is greater in organically managed soils with reduced tilling compared to conventional methods, a new Swiss study suggests. This illustrates the impacts that land management practices such as ploughing can have on soil biodiversity and the ecosystem services it provides.

Planting a variety of crop species in rotation in agricultural fields increases the diversity of soil microbes below ground, recent research has found. This in turn positively affects soil organic matter, soil structure and aids the healthy functioning of the soil. The researchers say that rotational diversity can help farmers to grow crops in a more sustainable way that promotes soil stability.

Plant diversity improves soil stability, the results of a greenhouse experiment and a long-term field study show. This study, which covered a range of different soil types, is one of the first to investigate the effects of plant diversity on soil structure, which is important for provision of ecosystem services, such as carbon storage and the mitigation of excessive run-off. The findings could help tackle the problem of soil degradation, the researchers suggest.

Natura 2000 sites have, on average, 10% more carbon in their topsoil than non-protected areas, according to new research. They also generally have lower economic value for agriculture. The results suggest that there is significant potential to develop win-win biodiversity conservation and climate change mitigation efforts within the EU.

A new study has investigated the effects of set-aside management —when fields are taken out of agricultural production — on common invertebrate decomposers in soil. The diversity of woodlice species was higher in set-aside fields compared to neighbouring wheat fields and this effect increased in older set-asides. This study highlights the importance of set-aside areas as habitats for soil invertebrates, which are important for soil health.

Moss helps prevent soil erosion on fire-damaged land, a Portuguese study suggests. The researchers analysed water that ran off from post-fire hillsides. They found less sediment and organic matter in run-off from patches of land with high levels of moss than from those with low levels of moss. Moss quickly establishes itself on land after fires, so the study suggests that land managers could take advantage of its restorative effects by deliberately encouraging its growth.

The warmer, drier conditions expected under on-going climate change will reduce the rates at which soil fauna and microbes decompose plant litter, suggests new research from Germany. This may have important implications for agriculture and natural ecosystems worldwide, as litter decomposition is a key process in cycling and distributing nutrients throughout ecosystems.

Considering the impact on soil carbon, biodiversity and ecotoxicity is important when assessing the environmental footprint of dairy products, suggests a new study, which explored the impacts of organic and conventional milk production in three types of system established in Western Europe. The study found that organic milk production had a significantly lower impact on ecotoxicity and biodiversity than conventional milk production, and suggests that including soil carbon changes in the assessment would result in greater reductions in the carbon footprint of organic, rather than conventional, milk — in some cases by up to 18%.

Exposure to polluted soil can affect human health, but the risk may vary depending on the soil type. A recent study has shown that the differing amounts of cadmium and lead that can be dissolved in the human digestive system can be predicted for contaminated agricultural, urban and woody habitat soils using a model. Its authors suggest this is a useful method for assessing the risks of contaminated land.

Recent research has found that silver nanoparticles in sewage sludge, which is used on agricultural land as a fertiliser, can be toxic to soil microorganisms. The researchers calculated that a maximum of 30mg of silver nanoparticles per kilogram of sludge can be applied to land before harm occurs, based on typical application rates in Germany of five tons per hectare of farmland every three years.

Land use changes over time have altered relations between soils and water cycles throughout the world. Soils have been lost and degraded, and the closely interlinked processes of soils and water have become an urgent issue for European policymakers. This Thematic Issue aims to provide a review of new research into the links between soil and water issues in Europe, including a message that the soil-water links must be considered at their proper spatial scales.

Wastewaters from fruit-packaging plants may contain preservative chemicals. When spread onto fields, these wastewaters affect the way soil microbes cycle nitrogen, new research has found. Although this may impair crop growth, according to the authors, the results could also lead to the development of new substances that reduce nitrate run-off from agricultural land.

Wastewater sludge is widely used to remove toxic polycyclic aromatic hydrocarbons (PAHs) from soil, and yet the mechanisms underlying this process remain unclear. A new study reveals the extent of PAH removal following different treatments, and could provide a useful resource for those looking to diminish the effects that these pollutants have both on people and on the environment.

Nanotechnology is a key enabling technology predicted to have many societal benefits, but there are also concerns about its risks to the environment. This study reviewed the effects of nanoparticles on soil microorganisms, showing that toxicity depends on the type of particle. The researchers make recommendations for improving environmental risk assessment, including performing experiments in soil and over longer time periods.

Researchers have experimented with microwave heating as a way of cleaning soils polluted with fuels, such as diesel and petrol. Soil type and moisture levels, as well as the strength of microwaves used, had a strong bearing on the overall effectiveness of the cleaning. The research shows that, at certain depths and in certain types of soil, microwaves can be a cost-effective way of cleaning polluted soils.

Sewage sludge and manure are sometimes added to soil to improve crop production. However, these ‘natural fertilisers’ may contain not only nutrients and organic matter but also antibacterial agents. This study investigated their impact on the microbes in soil, revealing an increase in antibiotic resistance genes. The researchers recommend greater efforts to remove antibiotic residues from wastewater and manure.

Maps of the risk of griffon vultures’ exposure to lead in north-eastern Spain have been produced in a new study. High-risk places are mountainous areas where there are high levels of bioavailable sources of lead in the soil, but also where game hunting is prevalent, and carcasses scavenged by the birds may contain lead ammunition.

A new study has mapped levels of chemical elements found in European agricultural soils. In most places, unusually high concentrations are linked to geology, such as high levels of arsenic in the Massif Central in France. Human activity is to blame in some small areas, for example high concentrations of mercury were found near London and Paris. Abnormal concentrations, both too low and too high, could pose an environmental risk. This new data can be used in conjunction with the REACH Regulation1 and can help identify areas where action may be needed in relation to toxic elements in the environment.

An investigation into the attitudes of Canadian soil-remediation experts has shown that they tend to prefer conventional remediation methods over phytoremediation — which relies on plants to clean soils — despite evidence that the latter can have advantages. The researchers behind the study highlight that this ‘status-quo bias’ poses a barrier to the uptake of novel technologies such as phytoremediation, and that scientists may need to find different ways of disseminating evidence to increase the use of new techniques among practitioners.