Agriculture Reference
In-Depth Information
6
Minimizing Environmental Impacts
of Livestock Production Using
Diet Optimization Models
L.E. Moraes and J.G. Fadel*
Department of Animal Science, University of California,
Davis, California, USA
Introduction
with the former Mineral Accounting system, in
which producers were taxed for positive balances
of nitrogen and phosphorus (Oenema, 2004).
The two principal categories of environ-
mental policies, in the regulation of gas emis-
sions, are taxes and limitations on the amounts
emitted by a firm (Weitzman, 1974). An exten-
sion of these two policy strategies is the cap and
trade policy scheme, in which total emissions are
capped but entities involved in the regulatory
process are allowed to trade residual credits or
permits. A cap and trade policy scheme has been
implemented in US power plants, in the attempt
to reduce mono-nitrogen and sulfur oxides. In
the Netherlands, a cap and trade system was
used to reduce nitrogen and phosphorus excre-
tion by livestock, under the former Mineral
Transfer Agreement System (Oenema, 2004). In
contexts such as this one, tax-based policies and
their derivations are options that can be adopted
not only to decrease nitrate water levels but also
to reduce other potential environmental impacts
of livestock production.
The management of a livestock production
unit requires that factors affecting the system,
such as profitability, animal welfare and sustain-
ability, be examined. Decisions are then made
based on the contribution of individual factors
The environmental impacts of agriculture have
received great attention in the last decade. Several
greenhouse gas (GHG) inventories have been
developed worldwide, and mineral and nitrogen
excretion from livestock is now subjected to
governmental regulation in many countries
(Oenema, 2004). In a recent report, nitrate levels
in drinking water were examined in the Tulare
Lake Basin and Monterey County portion of the
Salinas Valley in California (Harter
et al
., 2012).
The region is responsible for 40% of California's
irrigated croplands and over half of California's
dairy herds. This region also supplies water for
2.6 million people, which rely on groundwater for
drinking purposes. The major source of human-
generated nitrate was croplands (96%), with the
two main sources being synthetic fertilizer (54%)
and manure applications (33%). Establishing a
tax on nitrogen fertilizers, including manure, was
one of the mitigation strategies proposed in the
report, prepared under contract with the State
Water Resources Control Board (Harter
et al
.,
2012). Tax-based policies have been implemen-
ted worldwide to act as mitigation strategies in
various economic sectors. For instance, in the
Netherlands, tax-based penalties were established
