Agriculture Reference
In-Depth Information
TABLE 16.23
Mean Annual C Input, C Depletion Rate, and Critical C Input Requirement
in Different Rainfed Production Systems
Mean Annual C
Input (Mg C
ha
-1
year
-1
)
Mean C
Depletion Rate
(Mg C ha
-1
year
-1
)
Critical C Input
Requirement
(Mg ha
-1
year
-1
)
Location/Production System
Anantapur (groundnut)
0.5-3.5
0.18
1.12
Bangalore (groundnut-finger
millet rotation)
0.3-3.0
0.92
1.62
Bangalore (finger millet)
0.3-3.1
0.25
1.13
Solapur
(winter sorghum)
0.6-3.4
0.23
1.10
SK Nagar (pearl millet)
0.2-1.9
0.67
3.30
Indore (soybean)
1.9-7.0
0.47
3.47
Varanasi (upland rice)
1.1-5.6
0.15
2.47
Sources:
Srinivasarao, Ch. et al.,
Land Degrad Develop
,
doi: 10.1002/ldr.1158, 2011. Srinivasarao, Ch. et
al.,
Eur J Agron
, doi: 10.1016/j.eja.2012.05.001, 2012. Srinivasarao, Ch. et al.,
Int J Agric
Sustain
, 10(3), 1-15, 2012. Srinivasarao, Ch. et al.,
J Plant Nutrition Soil Sci
, doi: 10.1002/
jpln.201000429, 2012. Srinivasarao, Ch. et al.,
Geoderma
, 175-176, 90-97, 2012. Srinivasarao,
Ch. et al.,
Can J Soil Sci
, 92, doi: 10.4141/cjss2011-098, 2012. Srinivasarao, Ch. et al.,
Soil Sci
Soc Am J
,
76(1), 168-178, 2012.
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
y
= -0.1072
x
+ 0.485
R
2
= 0.05005
0
0
0.5 1
Mean annual C input (Mg C ha
-1
year
-1
)
1.5
2
FIGURE 16.15
Relationship between mean annual C inputs and mean C depletion rate in
seven long-term experiments.
al. 2009). Globally, rates of C sequestration by different types of management range
from 0.11 to 3.04 Mg C ha
-1
year
-1
, with a mean of 0.54 Mg C ha
-1
year
-1
, and are
highly influenced by biome type and climate (Conant et al. 2001). The positive linear
relationship between the changes in SOC stock and the total cumulative C inputs to
the soils (external organics plus CR) over the years has been highly significant and
indicates that even after 13 to 27 years of C input, ranging from 0.2-1.9 to 1.9-7.0
Mg C ha
-1
year
-1
in the pearl millet-based systems, the unsaturated C sink capacity is
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