Environmental Engineering Reference
In-Depth Information
(FAO
2008
) with a depth of more than 1 m and drainage from poorly to imperfectly.
The percentage of clays is 56 % and pH is 6.5. Roots reach down to 30 cm and more
than 90 % of roots is placed in the first 15 cm. Starting from the last 50 years the area
has been managed by a combination of clipping/harvesting and cattle grazing. The
Eddy Covariance flux tower has been installed in June 2002 and the measurements
have been carried out until July 2008 (Gilmanov et al.
2007
; Wohlfahrt et al.
2008
).
2.2.2 Beano (IT-Be1 and IT-Be2)
An agricultural field of 13.3 ha was selected in the north-eastern part of Italy in
the late autumn of 2006. In this field, irrigated maize (
Zea mays
L.) was cultivated
during the last 30 years and the soil was tilled using a winter plow to a depth of
0.35 m and a spring soil preparation (5 cm) prior to sowing. A quite constant high
yield (10-11 Mg ha
−
1
dry matter) was achieved using a sprinkler irrigation sys-
tem and adding chemical fertilizers used in accordance with standard practices. The
average annual temperature at the site was 13.7 °C and annual precipitation was
around 1,200 mm (2000-2007). Soil can be classified as a Chromi-Endoskeletic
Cambisol (FAO
2008
) with the following characteristics in the 0-30 cm horizon:
total SOC
=
48.4 8.5 Mg C ha
−
1
, total N
=
4.2 1.1 MgN ha
−
1
, soil bulk den-
sity
=
1.25 0.15 g cm
−
3
, soil field capacity
=
23 % v/v, wilting point
=
12 %
v/v and pH
=
7.1 0.02 (Alberti et al.
2010
). The study area was divided into two
sections obtaining an eastern area of 8.6 ha and a western area of 4.7 ha. Maize
was cultivated in the East field (IT-Be1, 46.00361° N; 13.0256° E) using similar
management practices described above. After harvest, grain was removed from the
field while residues were left there (harvest index: 50 %). Instead, the West field
(IT-Be2, 46.00431° N; 13.02776° E) was converted to fodder alfalfa (
Medicago
sativa
L.), with a late winter plowing at 0.35 m (February 2007). At sowing,
39 kg ha
−
1
of seeds were used. No N fertilization was performed in IT-Be2. Alfalfa
was maintained from 2007 to 2009 with an average of four harvests during summer.
In 2010, IT-Be2 was converted again to maize with a minimum tillage (0-5 cm)
before sowing and following the same management practices used in IT-Be1.
2.2.3 Bonis (IT-Bon)
The experimental site is located in Southern Italy, in the Sila Greca mountain
range, in the region of Calabria (39.47778° N; 16.53472° E). The watershed area
is 140 ha, ranging from 975 to 1,300 m.a.s.l. and has been reforested between
40 and 50 years ago with conifers (
Pinus nigra
J.F. Arnold subsp.
laricio
, 80 %)
and broad-leaves (
Castanea sativa
L., 6 %). The remaining surface is covered
by pastures, crops, creeks and bare soil. The area is characterized by a Mountain
Mediterranean climate with variable but generally sufficient rainfall (1,170 mm)
