Agriculture Reference
In-Depth Information
Approximately 400 gal of oil equivalent is used annually to produce the
food that feeds each American; 19% of this is used to operate fi eld ma-
chinery [2]. Precision technologies such as auto guidance reduce overlap-
ping of passes while planting seeds or applying chemicals and fertilizers,
which results in less fuel usage and labor time. The decreased application
of chemicals and fertilizer also results in reduction of energy consumption
by the agricultural machinery and reduced expenditure on inputs.
Natural Resource Conservation Service (NRCS) of the United States
Department of Agriculture (USDA) estimates that even if only 10% of
the US farmers use a guidance system for planting seeds in the USA, 16
million gallons of fuel, four million pounds of insecticide, and two million
quarts of herbicide can be saved annually [1]. This will not only result in
energy savings, but also fi nancial savings for producers. A study by Clem-
son University showed that spatially varied tillage depth reduced energy
requirements by 56% and fuel consumption by 34%. They also found that
there is a potential energy savings of up to 52% by using variable rate ir-
rigation systems [3].
Little research has been done relative to energy saving through pre-
cision agriculture, but USDA-NRCS has estimated the savings. A recent
study by USDA notes that overlaps can be reduced from 24 to 2 in. by
using a guidance system, which saves about US$13,000 in variable costs
annually for a farm of 1,000 acres [1]. Based on these estimates, a GPS
guidance system provides a substantial return on investment and pays for
itself within one year. The return on investment increases with the size of
the farm as the annual savings increase and the equipment cost is spread
over more acreage. Provision of free GPS signals by the federal govern-
ment has encouraged producers to use new precision tools, techniques,
and services to enhance their efforts to save energy and reduce costs [1].
Different tillage systems can also play an important role in reduc-
ing fossil fuel use in farming operations. By practicing no-till farming, a
farmer can save 3.9 gal/ac, or US13.65/ac, assuming diesel fuel costs of
US3.50/gal [4]. Shibusawa [5] noted that the energy input-output ratio
for crop production is very high, especially in fruits and vegetables. The
machinery fuels and agro-chemicals derived from fossil fuels (including
fertilizers, herbicides, and pesticides) are the major sources of high energy
inputs in crop production systems.
