Water Savings through
Conservation Tillage
Gary L. Hawkins, Ph.D., Biological and Agricultural Engineering,
Ag Pollution Prevention - Row Crops
Dana Sullivan, USDA-ARS, Soil Scientist
Clint Truman, USDA-ARS, Soil Scientist
Cotton, corn and peanut production in Georgia
covers 2.3 million acres and is an $867 million business
annually. On 30 percent of those acres, conservation
tillage is the preferred method of operation. Conservation tillage is a systems approach that has benefits such
as reduced fuel usage, improved soil quality, and
reduced erosion. Water saving, one of the most
important benefits of conservation tillage, is often
overlooked. Considering that 49, 55, and 56 percent of
cotton, corn, and peanuts receive irrigation, conservation
tillage can save a significant amount of water and energy
statewide. Conservation tillage systems, coupled with
the use of cover crops, increase water infiltration by as
much as 30 to 45 percent compared to conventional
tillage systems for loamy sand and sandy loam soils.
This means more efficient use of rainfall and irrigation
water, as well as less water carrying sediment and
agrochemicals running off fields into waterways.
Increased infiltration, in any soil type, is beneficial
to the farmer because it reduces the amount of water
applied by irrigation (Reeves et al., 2005). In dryland
systems, increased infiltration may have an even greater
impact on crop yields. Increasing infiltration is particularly important in the Coastal Plain, where sandy,
drought-prone soils are common.
Statewide, as conservation tillage increases, the
amount of water savings as compared to conventional
tillage production systems, is estimated to increase as
follows:
At the current adoption rates (30 percent) and based
on published data, water savings on the 1.3 million acres
of cotton in Georgia amounts to 4.4 billion gallons
annually (numbers for corn and peanuts would be .33
and 1.0 billion gallons respectively). Values for cotton
were calculated using these assumptions (2004 data):
1,300,00 acres of planted cotton in Georgia
(Georgia Agricultural Statistics, 2004)
30 percent adoption rate of conservation tillage in Georgia
(Conservation Technology Information Center)
41.5 percent of the cotton is irrigated
(Kerry Harrison, 2005)
1 irrigation application saved per growing season – 1' per
application
(Truman and Rowland, 2005; Hawkins, et al., 2007)
27,154 gallons per acre-inch of water
This information, along with calculated values for
40 and 100 percent adoption, is in Figure 1. It highlights
current and potential water savings using conservation
tillage systems. Another way to look at the amount of
water saved by agricultural producers using conservation
tillage is by putting it in terms of water used (based on
average daily consumption – Fanning, 2003) for various
cities. Estimates were calculated using the current rate of
conservation tillage adoption (30 percent):
30% adoption (current rate)
3-12% water savings
Atlanta
3 months-1 year
40% adoption
5-18% water savings
Macon
1-3 years
Savannah
1½-6 years
100% adoption (full adoption)
12-46% water savings
Results are a function of management: para-tillage, striptillage with residue removed, strip-tillage with residue
remaining or no-till. Savings are calculated based on
estimated water use in 100 percent conventional tillage
adoption.
References:
Fanning, J.L. 2003. Water use in Georgia by county for
2000 and Water-use trends for 1980–2000. Georgia
Department of Natural Resources Information
Circular 106, 176 p., also online at
http://ga.water.usgs.gov/pubs/other/ggs-ic106/
Georgia Agricultural Statistics. 2005. Georgia
Agricultural Facts, 2004 Edition.
Harrison, K. 2005. A memo addressed to County
Extension Agents concerning 2004 Irrigation
Survey.
Figure 1. Comparison of different adoption rates of conservation tillage and the potential water savings in Georgia
associated with the three row crops in the state.
This information is presented to highlight current
and potential water savings using conservation tillage
systems in Georgia. Through a partnership with the
University of Georgia – College of Agricultural and
Environmental Sciences, USDA-Agricultural Research
Service, USDA-Natural Resource Conservation Service
(NRCS), Soil and Water Conservation Society and
Resource Conservation and Development Councils,
Agricultural Pollution Prevention Program, and the
Pollution Prevention Division of Georgia DNR, research
and education programs on water savings through use of
conservation tillage continues in the agricultural
community. If you have further questions on issues such
as cover crops, tillage, how-to’s or other aspects of
conservation tillage or water savings, please contact Dr.
Gary L. Hawkins, UGA Biological and Agricultural
Engineering, Tifton, 229-386-3914, Dr. Dana Sullivan,
USDA-ARS, Tifton, 229-386-3665, Dr. Clint Truman,
USDA-ARS Tifton, 229 386-7174, your local UGA
Extension Agent (1-800-ASK-UGA1) or NRCS Agent.
Hawkins, G.L., D. Sullivan, G. Bland, C. Truman, T.
Strickland, B. Hubbard, R.D. Lee, J. Beasley. 2007.
Thermal Infrared Imagery for Better Water
Conservation in Agricultural Fields. Proceedings
2007 Georgia Water Resources Conference, held
March 27-29, 2007, at the University of Georgia,
Athens Ga.
Reeves, D.W., M.L. Norfleet, D.A. Stark, H.H.
Schomberg, H. Causarano, and G.L. Hawkins. 2005.
Conservation tillage in Georgia: economics and
water resources. Proceedings 2005 Georgia Water
Resources Conference, University of Georgia,
Athens Ga, April 25-27, 2005. Available at:
http://gwri.ce.gatech.edu/GAConf/Proceedings/2005
/Papers/ReevesW-GWRCpaper%20revised.pdf
Truman, C.C., and D.L. Rowland. 2005. Conservation
Tillage to manage water and supplemental irrigation
in Georgia. Proceedings 2005 Georgia Water
Resources Conference, held April 25-27, 2005, at
the University of Georgia. Kathryn J. Hatcher,
editor, Institute Ecology. The University of Georgia,
Athens, Ga.
T he University of G eorgia and Ft. Valley State University, the U.S. Department of Agriculture and counties of the state cooperating. Cooperative Extension, the
University of G eorgia College of Agricultural and Environmental Sciences, offers educational programs, assistance and materials to all people without regard to race,
color, national origin, age, gender or disability.
An Equal O pportunity Em ployer/Affirmative Action O rganization C om mitted to a D iverse Work Force
C 916
July 2007
Issued in furtherance of Cooperative Extension work, Acts of M ay 8 and June 30, 1914, T he University of G eorgia College of Agricultural and Environmental Sciences
and the U.S. Department of Agriculture cooperating.
J. Scott Angle, D ean and D irector