Impacts of Land-use Change on Carbon Stocks and Dynamics in Central-southern South American Biomes: Cerrado, Atlantic Forest and Southern Grasslands - Soil Carbon: Science, Management and Policy for Multiple Benefits - page 253

accumulation and stabilization, as shown
by Jantalia et al . (2007) ( Fig. 21.7) . In a soil
under NT for one year, the SCSs fell by 33%
and 17% when compared with native vege-
tation and conventional tillage (CT), re-
spectively. However, 12 years after the crop
management change, SCSs were similar to
those under the native vegetation and 26%
higher than under CT. Corazza et al . (1999)
found high rates of carbon sequestration in
soils under no-till systems (1.43 Mg C ha - 1
year -1 ) in sites of the Federal District of Brazil,
located in the Cerrado biome. This depend-
ency on time was also shown by Siqueira
Neto and co-workers (Siqueira Neto, 2006;
Siqueira Neto et al ., 2010).
The literature shows a wide range of
carbon sequestration rates in Cerrado biome
soils according to land use, crop and soil
management (0.3-1.91 Mg ha - 1 year -1 ).
A literature survey, including 40 scien-
tific articles and several papers presented at
Brazilian soil scientific meetings reporting
SCS measurements under different soil
types, land uses and management in the
Cerrado biome shows that, on average, NT
systems consistently promote the highest

levels of SCSs, an average of 76.73 Mg C ha - 1
year - 1 , at a depth of 0-40 cm (Table 21.1 ).
In general, the conversion of native
Cerrado and Atlantic Forest vegetation into
annual or perennial crops (including sugar-
cane and eucalyptus, with the exception of
pasture) reduces SCSs drastically (Guo and
Gifford, 2002; Carvalho et al ., 2010b; Melil-
lo et al ., 2011). These results were corrobor-
ated by Kaschuk et al . (2011), who used data
integration and meta-analysis approaches to
analyse soil biological and chemical attri-
butes from different Brazilian biomes and
land uses. The authors demonstrate that, in
general, the conversion of native vegetation
to annual crops has a strong negative impact
on all variables studied (carbon in the soil
microbial biomass, total organic soil carbon
and metabolic coefficient), this being more
pronounced in the Cerrado biome.
The literature data show a wide range of
carbon sequestration rate values in Cerrado
biome soils according to land use, crop, soil
and postharvest management. Systems under
NT, crop rotation or consociation with
nitrogen-fixing legume species show the
highest carbon sequestration potentials, with

350

A

300

a

ab

abc

B

bc

250

c

bc

200

150

A

a

100

ab

bc

B

cd

de

e

50

0

MPZT DPZT MPT1 DPT1 MPT2 DPT2 All tillage

treatments

Native
vegetation

Tillage treatment

0-100 cm 0-30 cm Mean values

Fig. 21.7. Soil carbon stocks at 0- 30 and 0-100 cm depths, under different tillage plots and a neighbouring
area with native Cerrado vegetation, at a field experiment in Embrapa Cerrados (Planaltina, DF, Brazil). DP and
MP represent plots tilled with a disc and mouldboard plough, respectively. ZT, T1 and T2 correspond to no-tillage,
tilling annually before sowing and tilling annually before sowing and after harvest, respectively. Means in the
same column followed by the same letter are not significiant at P < 0.05 ( t -test). (From Jantalia et al ., 2007.)