Collection

Soil and its sustainability

Healthy and productive soils are central to achieving a number of the 17 sustainable development goals adopted by the United Nations General Assembly this year. Soils sustain our food systems, filter and regulate the flow of freshwater, store vast quantities of carbon and support myriad organisms. But the world’s soils are increasingly under pressure from climate change, population growth and poor land management.

This collection brings together a selection of articles that explore soil in its manifold roles in shaping the Earth’s environment and human society. The make-up and management of soils, and their influence on human health and extreme poverty, are some of the topics investigated.

The United Nations General Assembly has declared 2015 the International Year of Soils to raise awareness of the life-supporting functions of soil.  We hope that the collection supports this aim and that the Year of Soils is a starting point for improved understanding, better protection and sustainable management of this precious resource.

News and Opinion

The fields of ecology and evolutionary biology are implicitly connected. A new theory that links the global distribution and evolution of nitrogen-fixing trees uses the universal language of mathematics to make this connection more explicit.

News & Views | | Nature Plants

Soil microorganisms have long been known to aid plants through nitrogen fixation and water and nutrient exchange. Now researchers are unearthing new ways in which this subterranean biome affects plant performance.

News | | Nature Plants

Decomposition of soil organic matter could be an important positive feedback to climate change. Geochemical properties of soils can help determine what fraction of soil carbon may be protected from climate-induced decomposition.

News & Views | | Nature Geoscience

The tremendous gains in crop yields seen over the twentieth century were underpinned by fertilizer use and manipulation of the aboveground parts of the plant. To meet the food demands of the twenty-first century, plant scientists must turn their attention belowground.

Comment | | Nature Plants

Climate change is a major threat to food production, so researchers are working with farmers to make agriculture more resilient.

News Feature | | Nature

Global studies of biodiversity paint a consistent picture of declines associated with human activity. At the same time, many studies at a local level have shown that biodiversity loss affects ecosystem functions and services. Tim Newbold et al. have assembled a global data set of local biodiversity trends — including 1% of the global total of named species — as a measure of how local terrestrial biodiversity responds to human pressures. The authors estimate that human-caused changes have already reduced average local species richness by 13.6% and total abundance by 10.7% during the past few centuries. Under projected business-as-usual land use scenarios, further substantial loss is expected this century, but there is room for strong mitigation efforts to reverse the effects.

News & Views | | Nature

A charcoal-rich product called biochar could boost agricultural yields and control pollution. Scientists are putting the trendy substance to the test.

News Feature | | Nature

Africa south of the Sahara is going through a major agricultural transformation. Low crop productivity, hunger and pessimism are being replaced by a rapid rise in food production, an increasingly vibrant agricultural value chain and convergence towards a common goal.

Comment | | Nature Plants

Most antibiotics in clinical use were discovered by screening cultivable soil microorganisms, a much depleted resource that has not been adequately replaced by synthetic approaches. Hence the widespread alarm at the spread of antibiotic resistance. This paper presents some welcome good news, in the form of the isolation and characterization of a new antibiotic active against a range of bacterial pathogens including Staphylococcus aureus, and apparently untroubled by the evolution of resistance. Kim Lewis and colleagues use a recently developed system for in situ cultivation of previously uncultured soil bacteria and identify a β-proteobacterium, Eleftheria terrae sp. that produces a depsipeptide they call teixobactin. Teixobactin is active in vivo and separately targets precursors in the biosynthetic pathways for each of two major components of the bacterial cell wall, peptidoglycan and teichoic acid. Screens for mutants resistant teixobactin were negative, perhaps a consequence of this novel two-target mechanism.

News & Views | | Nature

Research

Soils, and agricultural soils in particular, could be useful in climate mitigation — offsetting human emissions of greenhouse gases. Changes in management practice have been shown to increase carbon sequestration and reduce the emission of greenhouse gases, and the global potential is on the order of several petagrams of CO2 equivalent per year. Accurately monitoring the effectiveness of soil management techniques, though, remains difficult. A larger challenge is rolling out the required practices at the scale required. Keith Paustian et al. discuss the many challenges in soils-based mitigation, and suggest ways forward in monitoring and implementation.

Perspective | | Nature

Careful management of nitrogen fertilizer usage is required to ensure food security for a growing world population while limiting environmental degradation as a consequence of nitrogen pollution. Xin Zhang et al. investigate historical patterns of agricultural nitrogen use efficiency and how socioeconomic policies and technological innovations can help improve nitrogen use efficiency and achieve the projected 2050 goals of food security and environmental stewardship.

Perspective | | Nature

Soil organic matter contains a large portion of the world's carbon and plays an important role in maintaining productive soils and water quality. Nevertheless, a consensus on the nature of soil organic matter is lacking. Johannes Lehmann and Markus Kleber argue that soil organic matter should no longer be seen as large and persistent, chemically unique substances, but as a continuum of progressively decomposing organic compounds.

Perspective | | Nature

Soils contain a rich biota, but this is threatened because of intensive agriculture and poor land management. Soil biodiversity has a key role in providing food, clean water and air, and in suppressing disease. Diana Wall, Uffe Nielsen and Johan Six review how these ecosystem services can be provided if soils are restored and managed sustainably.

Perspective | | Nature

Belowground soil biota play key roles in maintaining proper ecosystem functioning, but studies on their extinction ecology are sparse. Here, Veresoglou et al. review the risks to soil biota posed by global change, and highlight the technical challenges involved in identifying extinction events.

Review Article | Open Access | | Nature Communications

Terrestrial ecosystem productivity is widely accepted to be nutrient limited. A series of standardized nutrient addition experiments, carried out on grasslands on five continents, suggests aboveground grassland productivity is commonly limited by multiple nutrients, including potassium and micronutrients.

Article | | Nature Plants

Temperatures have risen faster than the global average in the Artic and sub-Arctic over the past thirty years. A warming climate thaws the frozen ground and accelerates the microbial decomposition of soil organic carbon stored in large quantities in this region, leading to the release of the greenhouse gases carbon dioxide and methane. This feedback effect can accelerate climate change, but the magnitude and timing of greenhouse gas emissions remains uncertain. In this Review, Ted Schurr et al. conclude that current evidence points to a gradual but prolonged release of carbon dioxide and methane in a warming climate. The authors identify poorly understood aspects of permafrost carbon dynamics.

Review Article | | Nature

The mechanisms driving soil carbon storage, one of the largest stores of terrestrial carbon, remain poorly understood. Here, the authors present data from the long-term Jena Experiment on grassland biodiversity, showing that elevated carbon storage at high plant diversity is a direct function of increased soil microbial activity.

Article | | Nature Communications

Global studies of biodiversity paint a consistent picture of declines associated with human activity. At the same time, many studies at a local level have shown that biodiversity loss affects ecosystem functions and services. Tim Newbold et al. have assembled a global data set of local biodiversity trends — including 1% of the global total of named species — as a measure of how local terrestrial biodiversity responds to human pressures. The authors estimate that human-caused changes have already reduced average local species richness by 13.6% and total abundance by 10.7% during the past few centuries. Under projected business-as-usual land use scenarios, further substantial loss is expected this century, but there is room for strong mitigation efforts to reverse the effects.

Article | | Nature

Most antibiotics in clinical use were discovered by screening cultivable soil microorganisms, a much depleted resource that has not been adequately replaced by synthetic approaches. Hence the widespread alarm at the spread of antibiotic resistance. This paper presents some welcome good news, in the form of the isolation and characterization of a new antibiotic active against a range of bacterial pathogens including Staphylococcus aureus, and apparently untroubled by the evolution of resistance. Kim Lewis and colleagues use a recently developed system for in situ cultivation of previously uncultured soil bacteria and identify a β-proteobacterium, Eleftheria terrae sp. that produces a depsipeptide they call teixobactin. Teixobactin is active in vivo and separately targets precursors in the biosynthetic pathways for each of two major components of the bacterial cell wall, peptidoglycan and teichoic acid. Screens for mutants resistant teixobactin were negative, perhaps a consequence of this novel two-target mechanism.

Article | | Nature