Climate-smart soils
Improved soil management can substantially
reduce greenhouse gas emissions from soils and sequester some of the carbon dioxide removed
from the atmosphere by plants, as carbon (C) in soil organic matter. In
addition, wise soil management that increases organic matter and tightens the
soil nitrogen (N) cycle can yield powerful synergies, such as enhanced
fertility and productivity, increased soil biodiversity, reduced erosion,
runoff and water pollution, and can help buffer crop and pasture systems against
the impacts of climate change.
This article highlights ‘state of the art’ soil greenhouse gas
research, summarises mitigation practices and potentials, identifies gaps in data
and understanding and suggests ways to close such gaps through new research,
technology and collaboration.
Although soils contribute a major share (37%; mainly as N2O and CH4) of agricultural emissions3, improved soil management can substantially reduce these emissions and sequester some of the CO2 removed from the atmosphere by plants, as carbon (C) in soil organic matter (in this Perspective, our discussion of soil C refers solely to organic C). In addition to decreasing GHG emissions and sequestering C, wise soil management that increases organic matter and tightens the soil nitrogen (N) cycle can yield powerful synergies, such as enhanced fertility and productivity, increased soil biodiversity, reduced erosion, runoff and water pollution, and can help buffer crop and pasture systems against the impacts of climate change4.Although soils contribute a major share (37%; mainly
as N
2
O and CH
4
) of agricultural emissions
3
, improved soil management
can substantially reduce these emissions and sequester some of the CO
2
removed from the atmosphere by plants, as carbon (C) in soil organic
matter (in this Perspective, our discussion of soil C refers solely to
organic C). In addition to decreasing GHG emissions and sequestering C,
wise soil management that increases organic matter and tightens the
soil nitrogen (N) cycle can yield powerful synergies, such as enhanced
fertility and productivity, increased soil biodiversity, reduced erosion,
runoff and water pollution, and can help buffer crop and pasture systems
against the impacts of climate change
4
.
Although soils contribute a major share (37%; mainly
as N
2
O and CH
4
) of agricultural emissions
3
, improved soil management
can substantially reduce these emissions and sequester some of the CO
2
removed from the atmosphere by plants, as carbon (C) in soil organic
matter (in this Perspective, our discussion of soil C refers solely to
organic C). In addition to decreasing GHG emissions and sequestering C,
wise soil management that increases organic matter and tightens the
soil nitrogen (N) cycle can yield powerful synergies, such as enhanced
fertility and productivity, increased soil biodiversity, reduced erosion,
runoff and water pollution, and can help buffer crop and pasture systems
against the impacts of climate change
4
.
Perennial agriculture is prone to declining productivity due
to negative plant-soil feedback. Although cover crops
are already used in these systems for other reasons, their capacity to
influence soil biota is unexploited. This article examines the role of plant
diversity and identity on plant-soil feedback. We conclude that (1) increasing plant diversity
increases soil microbial diversity, minimizing the proliferation of
soil-borne pathogens; (2) populations of beneficial microbes can be
increased by increasing plant functional group richness, (3) brassicas suppress fungal
pathogens and promote disease-suppressive bacteria; (4) native plants
may further promote beneficial soil microbiota; and (5) frequent
tillage, herbicide use, and copper fungicides can harm populations of
beneficial microbes. Non-crop vegetation management is a viable and cost-effective
means of minimizing crop decline in perennial monocultures. 
