Soil and its sustainability

Luca Montanarella calls for a voluntary international agreement to protect the ground beneath our feet from erosion and degradation.

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.

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.

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.

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.

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

Long overlooked in parts of Africa, indigenous greens are now capturing attention for their nutritional and environmental benefits.

Forensic geologist Lorna Dawson has pioneered methods to help convict criminals using the dirt from their shoes.

A meta-analysis at a local scale reveals that land-use change has caused species richness to decline by approximately 8.1% on average globally, mainly as a result of large increases in croplands and pastures. See Article p.45

Meeting global food needs requires strategies for storing rainwater and retaining soil moisture to bridge dry spells, urge Johan Rockström and Malin Falkenmark.

The country’s shifting stance on genetic modification for crops needs the support of researchers to persuade a sceptical public, says Qiang Wang.

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

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.

A screen of 10,000 bacterial strains, cultured in their normal soil, has uncovered an antibiotic with broad and potent activity. And because the compound targets lipid molecules, developing resistance is probably difficult. See Article p.455

The potential of soils to mitigate greenhouse gas emissions has not been exploited; here we discuss and recommend research and technology developments to implement mitigation practices.

Careful management of nitrogen fertilizer usage is required to ensure world food security while limiting environmental degradation; an analysis of historical nitrogen use efficiency reveals socio-economic factors and technological innovations that have influenced a range of past national trends and that suggest ways to improve global food production and environmental stewardship by 2050.

Low soil fertility can limit crop productivity, which in turn constrains the ability of poor households to invest in improving soils. This self-reinforcing feedback can trap households in chronic poverty for years or even generations.

Instead of containing stable and chemically unique ‘humic substances’, as has been widely accepted, soil organic matter is a mixture of progressively decomposing organic compounds; this has broad implications for soil science and its applications.

Soil biodiversity sustains human health and its loss can be mitigated by sustainable management.

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.

This study finds significant positive associations between the diversity of soil fungi and surface air temperature in the maritime Antarctic, one of the most rapidly warming regions on Earth.

Soil organic matter is a large global carbon pool. Isotopic labelling of litter in the lab and the field reveals that soil organic matter forms from labile organic compounds and litter fragments early and late in decomposition, respectively.

Rising temperature can increase soil organic matter decomposition and CO₂ emissions. In a 4,000 km north–south transect in Chile and Antarctica, soil geochemistry, which can be modified by climate, is the dominant direct control of carbon storage.

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.

In this Opinion article, James Prosser considers the conceptual limitations of metagenomics and metatranscriptomics in contributing to our understanding of soil microbial ecology, and also explores potential opportunities for using these techniques to address specific ecological questions.

A large amount of organic carbon stored in frozen Arctic soils (permafrost) could be released as carbon dioxide and methane in a warming climate, which would accelerate the pace of climate change; this review suggests that release of greenhouse gas emissions will be gradual but prolonged.

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.

Analysis of a global data set of local biodiversity comparisons reveals an average 13.6% reduction in species richness and 10.7% reduction in abundance as a result of past human land use, and projections based on these data under a business-as-usual land-use scenario predict further substantial loss this century, unless strong mitigation efforts are undertaken to reverse the effects.

From a new species of β-proteobacteria, an antibiotic called teixobactin that does not generate resistance has been characterized; the antibiotic has two different lipid targets in different bacterial cell wall synthesis components, which may explain why resistance was not observed.