Soil Carbon Transition Curves: Reversal of Land Degradation through Management of Soil Organic Matter for Multiple Benefits - Soil Carbon: Science, Management and Policy for Multiple Benefits - page 39

Are the direct benefits to the farmer at the
local level sufficient; do farmers have long-
term security of tenure or are regulatory
actions and/or economic incentives needed
in order to attain multiple benefits at the
local, landscape and global levels? A strategy
may be needed to move the importance of
healthy, productive soils more to the core
of mainstream decision making (Chapter 5,
this volume).
Economic incentives to assist in the
co-production of public goods often start as
additional ways to initiate decisions that
lead into the synergy stage of the soil carbon
transition curve (Stage III), but they may be-
come seen as entitlements (Swallow et al .,
2009). The question is whether the impacts
of local soil carbon transition warrant ac-
tion on the global costs/benefits of reduced/
enhanced soil carbon storage, above and be-
yond what makes sense at the landscape
scale. The concept of a global carbon market
is built on the idea that it might lead to effi-
cient responses - but a more segmented par-
tial market approach or a compensation/
co-investment approach is an alternative
(Namirembe et al ., 2014; Chapter 31, this
volume).
One way of turning trade-offs into syn-
ergies is the implementation of good agri-
cultural practice, and increasingly this is
becoming a precondition for acceptance in
global commodity trade. Good agricultural
practice is enforceable in World Trade Or-
ganization rules (as non-compliance is seen
as an undue subsidy of farming) and as such
has a much larger reach than the Fair Trade
model, as exists, for example, in the tea,
cocoa and coffee markets. The global bene-
fits of increased soil carbon storage may be
achieved on the back of such market-based
responses - in ways that are unexpected by
those who seek measurable increases in soil
carbon as quid pro quo in targeted soil car-
bon payments. Good agricultural practice
concepts are location specific. There is,
therefore, a need to link practices and pol-
icies across scales. One challenge is that
local decisions are often more focused on
short-term gain rather than long-term bene-
fits (Chapter 2, this volume). Yet a long-term
focus is what may be required to move from

a situation whereby humanity has lived off
the land for decades without sufficient re-
turns towards sustainable synergistic ap-
proaches to land use, leading to multiple
ecosystem benefits across scales in both the
short as well as the long term.

Good agricultural practices for strategic
areas of high carbon sequestration
potential

Worldwide, there are three situations that
have the highest potential for sequestrating
carbon in the soil. One case is the vast areas
of degraded agricultural lands in semi-arid
climates that originally were grasslands, sa-
vannahs or tropical dry forests. The second
case is tropical wetlands or peats that have
been drained and cultivated; beyond avoided
losses, these also have a potential to gain
carbon when good close-to-natural agricul-
tural practices are carried out. As a third
issue, temperate draining of wetlands and
management of subarctic permafrosts are of
global importance in emission terms.
Taking as an example the semi-arid
agricultural lands of North America, the soil
organic carbon contents have diminished
by, on average, 50% during the arable agri-
culture period. Similar consideration is
valid for arid land in China, Mongolia, Rus-
sia, Africa and South America. Despite the
inherently low carbon contents of their
soils, drylands represent 41% of the global
land area, with their use characterized as
45% rangeland and 25% cultivated land
(MA, 2005). These regions therefore collect-
ively represent the highest potential for car-
bon sequestration. The potential to seques-
ter soil carbon is estimated at 0.4-0.6 billion
t year - 1 if drylands degradation worldwide
is completely reversed and arrested (Lal,
2001). This rationale is based on the magni-
tude of previous carbon loss and the intrin-
sic capacity of these soils to accumulate or-
ganic matter - as an indicator of potential
future gains that are very high in these soils.
Good agricultural practices are at the
core of realizing the potential to sequester
carbon in semi-arid arable lands. Bhattacha-
ryya et al . (2007b) have given an overview