DaFonte
9/22/10
BRAE Bryce 236 Lab 1
Irrigation System Tour
Station 1: Border Irrigation
As a group we were asked to use a stopwatch and tape measure to measure and record the time it
takes for water to advance down the field once one of the borders was turned on. At time = 0
seconds the border was turned on. We observed the following data:
Distance Down Field (ft)
Time (min:sec)
10
:45
20
1:35
30
2:40
40
3:56
50
5:20
Station 2: Furrow Irrigation
The group was asked to set up the pipe by opening two gaps to two finger-widths each. We
attached a dissipation sock to one gap and turned the system on. After the system ran for a couple
minutes, we noticed that the furrow that was being hit by the non-dissipated gap of water was
deteriorating as the high velocity water from the pipe was eroding the side of the furrow.
However, the gap that had the dissipation sock connected to it dispensed water to the furrow that
had a much lower velocity, thus reducing the amount of erosion greatly. We then turned the
system, and put a dissipation sock on the second gap in the pipe for the second furrow. A dam
was placed in one furrow a short distance from the head of field. The water in the dammed
furrow rose to a higher level up the sides of the furrow, thus allowing the watering of the higher
sections of the furrows. This creates less run off, and the longer the water sits in the furrow, the
higher the furrow gets watered. The main differences between furrow irrigation and border strip
irrigation is that the border strips are about 10-15 feet wide, while the furrows are only about 1
foot wide, thus specifying more precisely where you want the water to go. It is possible to use
furrow irrigation to irrigate 1-inch during a single event by the use of a dam. Each person in the
group also had to get a siphon to work. The group then had to measure the flow rate from one
siphon tube by filling up a five gallon bucket and timing how long that process took. The the siphon
filled five gallon bucket in 51 seconds, thus resulting in a flow rate of 5.88 gpm. Siphon
tubes work by creating a vacuum in the tube that uses gravity to force the water from a higher
location through the siphon tube and out to a location lower than the entrance of the tube.
Station 3: Drip Irrigation
The group then had to turn on a drip hose and not emitter spacing. We then measured the flow
rate of 1 emitter. One emitter filled a container with 102 ml of water in 10 minutes, thus using
dimensional analysis, the following flow rate can be found:
(102 ml/10 min) x (60 min/1 hr) x (0.000264 gal/ml) = .16158 = .162 gal/hr
We then had to cut apart one inline emitter and one online emitter. The inline emitters have the
hoses, tapes and openings built into the tape. Once cutting open the tape, the locations of each of
these was easily seen. The openings have a diameter of .5 mm, and the water coming in needs to
be filtered to the opening no bigger than 1/10 the size of the opening. The online emitters are
manufactured separately and then stuck into the hose through holes that are created by the user.
The inside of the manufactured piece looks like a maze that the water must travel through and
then make its way out the exit hole. This is possibly used to lower the velocity of the water
entering the emitter to a speed that just drips out of the exit hole. A rough sketch of each is
shown below, including arrows pointing where water enters and exits the emitter, as well as the
path the water takes through the emitter.
Station 4: Sprinkler Irrigation
We had to set up and turn on a line of sprinklers, which included 4 separate pipes with one
sprinkler located on each, and an end cap for the end pipe. We then measured the flow rate from
one sprinkler by recording the time it took to fill up a five gallon bottle. The five gallon bottle
took 1 minute and 3 seconds to fill, which results in a flow rate from one sprinkler of 4.76 gpm.