Download - Subsurface Drip Irrigation
Subsurface Drip Irrigation
Jordan GatlinSOIL 4213
April 15, 2013
What is SDI? In subsurface drip irrigation, drip tape is
buried below the soil surface Effective tool for water placement
http://www.cottoninc.com/fiber/AgriculturalDisciplines/Engineering/Irrigation-Management/Irrigation-Systems-Overview/
http://home.howstuffworks.com/irrigation4.htm
Components Pump Filtration system
Sand media or disk filter
Based on water quality, emitter requirements, and system flow rate
“Heart” of the system Pressure gauge Backflow preventer Pressure regulator valves
Components Fertilizer injector Flowmeter Main line Sub-mains Flushing manifold Lateral drip tape Emitters
Components Computer
Used to program different irrigation schedules
Allows system to be automated
Logs volume of water moved through system
Installation Drip line is installed by tractor Depths vary from 6—24” Shallower in sandy soils, deeper in clayey soils Width is typically set on a 60” row spacing
Crops such as alfalfa 40” The wider the row spacing, the fewer the
rotation options
Pros Water is used more efficiently. It is placed
directly where it is needed, at the roots, and does not hit leaves on the way down from the sprinkler or evaporate
This also leads to less disease pressure, due to drier surface conditions and canopies that could inhibit spread of disease
Water can be managed at a variable rate if needed
Pros Limited weed growth and decreased weed
germination because water is not on surface Field operations can occur during irrigation Can irrigate in conjunction with nutrient
management practices, i.e. nitrogen or swine effluent application
No runoff because the water is applied below ground
Cons High initial installation cost System can get clogged (emitters,
pump, etc) Few visual indicators of system
operation If something goes wrong, the tape may
have to be excavated to diagnose and fix
http://www.hpwd.com/media/photo-library
Cons Rodent tunneling may damage the tape Equipment may damage the tape If there is not enough pressure to drive
the system, it will not operate correctly Pressure valves and sensors may fail
Cost Anywhere between $1000 –2000 per acre
Can be installed by producer to minimize costs EQIP—2008 Farm Bill provided funds to install SDI,
and can also help with improvements Requires NRCS to give priority to applications that
demonstrate a reduction in water use by the agricultural operation
Maintenance Can be costly, especially when major repairs occur Sand filters have to be replaced each year
Life Expectancy Normally 12—15 years System needs to be active for at least 10—15
years to reasonably approach economic competitiveness with full sized center pivot sprinklers that typically last 20+ years
Future Applications? One future application that SDI is being
proposed for is to limit water use/increase water use efficiency in the Oklahoma Panhandle/Ogallala Aquifer area.
This area has been hit hard by drought and decline in groundwater levels.
SDI can be used to better control the use of water from this important resource.
Questions?
Sources http://www.daff.qld.gov.au/26_4365.htm http://
www.hpwd.com/public/pdfs/New%20SDI%20booklet%20from%20NRCS.pdf
http://www.ksre.ksu.edu/sdi/ http://www.ext.colostate.edu/pubs/crops/04716.html