Environmental Engineering Reference
In-Depth Information
An emission of N
2
O of 1.52 ( 0.04) Mt CO
2
eq yr
−
1
and a slight sink of
CH
4
(
−
0.08 0.001 Mt CO
2
eq yr
−
1
) has been assessed for the five main crops which
represented 54% of the total harvested land in 2009, excluding rice paddies (Lugato
et al., 2010). Applying the emission factor (EF, kg N
2
O-N/kg extra N) of 0.8% (derived
from the range 0.4 to 0.8% provided by Chapter 9 and 10) to the total amount of
fertilizer N consumed in Italy in 2009 (514.480 tons of N) (FAOSTAT
2014
) and con-
sidering a similar flux strength for the remaining Italian harvested land, the total amount
of N
2
O emissions in CO
2
equivalent is 1.93 ( 0.09) Mt CO
2
eq yr
−
1
for 2009 while
the total sink of CH
4
(excluding rice cultivation) is
−
0.148 ( 0.002) Mt CO
2
eq yr
−
1
(Table
1.7
).
Table
1.8
shows SOC stock variations related to different management prac-
tices, ranging from a carbon sequestration potential of 26-67 g C m
2
y
−
1
when
Table 1.7
Fluxes of N
2
O and CH
4
, expressed as CO
2
equivalents, in soils of Italian croplands
and woodland crops for year 2009 (rice paddies excluded)
Parameters
Total fluxes of
GHG (Mt CO
2
eq)
Comments
1.93 (
0.09)
N
2
O
Estimated applying an EF of 0.8 % to total N fertilizer
consumption in 2009 (Chapter 9 and 10) Sum of
−
0.08 Mt CO
2
eq from modeling simulation
applied to 54 % of national harvested land, and
−
0.068 Mt CO
2
eq extrapolated applying a similar
GHG source strength (tons CO
2
eq/ha) to the
remaining harvested land (excluding ricepaddies)
(Lugato et al
2010
).
-0.148 ( 0.002)
CH
4
Table 1.8
SOC stock variations related to different management practices (the negative sign
indicates a sequestration potential)
Parameters
Total carbon
(g C m
2
y
Comments
−
1
)
SOC—Average annual carbon
loss (with no mitigation
options)
20-50
SOC loss in Italian croplands
Gardi and Sconosciuto (
2007
),
Janssens et al. (
2005
), Lugato et al.
16
Calculated as difference between 1990
and 2000 (Chap.
8
)
SOC—Annual carbon loss
(with no mitigation options)
Permanent set a side or zero
tillage
−
40
Carbon sequestration potential in soils
of mitigation options in Italian crop-
lands. Freibauer et al. (
2004
), Smith
et al. (
2000a
,
b
) (Chap.
8
)
−
60
Perennial crops or deep rooting
crops
−
50
Change from conventional to
organic farming
Best management practice:
change from cropland to
grassland; no-till; farm yard
manure
−
26 to
−
67
Field experiments (Morari et al.
2006
;
Lugato et al.
2006
; Triberti et al.
2008
;
+
27 %
Abandonment of a vineyard
−
43 % initially
Re-planting