Environmental Engineering Reference
In-Depth Information
main long-term experiments present in Italy by integrating experimental and mode
ling approaches, which can provide national emission rates and a solid base to test
and calibrate simulation models to estimate greenhouse gases emissions from Italian
agricultural soils. What emerges clearly from the analysis is that the agro-ecosys-
tems may sequester large amount of SOC if appropriate management practices are
adopted. Moreover, the use of simulation models calibrated at local level and spa-
tially applied, as done for the Carboitaly project, may certainly reduce the uncer-
tainty of these estimations.
10.1 Measuring and Modeling GHG Balance
in Agriculture: From Field to Territory
10.1.1 Field Experiments and Chronosequences
SOC and nitrogen cycles in agricultural soils may be strongly variable both in time
and space, therefore the study of their dynamics often requires different levels and
approaches of investigation.
Measurements of CO
2
fluxes from agro-ecosystems are often too short to detect
non-linear and long-term trends related to land use and management change. In
fact, SOC has an average mean residence time in the order of years (Kuzyakov
2006
), hence the effect of agricultural practices on C stock may be better analyzed
in long-term trials. These experiments can provide specific country values that
may help to improve the accuracy of the National Inventory Report (NIR) by the
implementation of a tier 2-3 approach.
Fortunately, some long-term experiments have been set-up in Italy in the past,
providing results that could be briefly reviewed. Morari et al. (
2006
) and Lugato
et al. (
2007
) published data of a long-term trial began in 1962 at the experimen-
tal farm of the University of Padova, located in Legnaro (NE Italy, 5026115 m N,
732390 m E). Another old trial, started in 1966 and located in Cadriano (BO-
4935649 m N, 686661 m E), was extensively analyzed by Triberti et al. (
2008
).
Furthermore, Mazzoncini et al. (
2011
) reported interesting results of a more
recent experiment, established in 1993 at the Interdepartmental Centre for Agro-
Environmental Research (4835964 m N; 606152 m E) by the University of Pisa.
All these trials have been carried out in field plots and are still undergoing.
The main outcomes of these experiments (Table
10.1
) clearly evidenced as rec-
ommended management practices could increase SOC of agricultural fields, mak-
ing the agriculture as an eligible sink under the future EU policies. In particular,
the change of land use from cropland to grassland, the no-till adoption and the use
of farm yard manure showed the higher sequestration rates, ranging from 0.26 to
0.67 t C ha
−
1
y
−
1
. The crop rotation had a marginal effect compared to monocul-
ture in Legnaro, while similar indications came from residues management, both
from trials conducted in Legnaro and Pisa.
