Over the past few weeks samples and tests have been completed on the AFRI Learning Lab. The tests being conducted are testing water, soil and air. The students are conducting their own samples for water and soil, while the air samples are being complete by members of the AFRI Team at UC Davis.
Below are a list of the test with results completed on August 7, 14, 21
Samples were taken from each side of the field and two samples were taken from each side.
Front part of the field to the middle dock is considered
Field A
Back part of the field is
Field B
There are two separate studies being completed (
Field A & B) because in
Field A nutrients were added to the field in the beginning of growing.
WATER SAMPLING:
Total Dissolved Solids (TDS)
Electrical Conductivity (EC)
Salinity
With this study we used a TDS meter: A TDS meter is based on the electrical conductivity (EC) of
water. Pure H20 has virtually zero conductivity. Conductivity is usually about
100 times the total cations or anions expressed as equivalents. TDS is
calculated by converting the EC by a factor of 0.5 to 1.0 times the EC,
depending upon the levels. Typically, the higher the level of EC, the higher
the conversion factor to determine the TDS. NOTE - While a TDS meter is based
on conductivity, TDS and conductivity are not the same thing.
Total Dissolved Solids (TDS) are the total amount of mobile
charged ions, including minerals, salts or metals dissolved in a given volume
of water, expressed in units of mg per unit volume of water (mg/L), also
referred to as parts per million (ppm). TDS is directly related to the purity
of water and the quality of water purification systems and affects everything
that consumes, lives in, or uses water, whether organic or inorganic, whether
for better or for worse.
Why Should You Measure the TDS Level in Your Water?
The EPA Secondary Regulations advise a maximum contamination
level (MCL) of 500mg/liter (500 parts per million (ppm)) for TDS. Numerous
water supplies exceed this level. When TDS levels exceed 1000mg/L it is
generally considered unfit for human consumption. A high level of TDS is an
indicator of potential concerns, and warrants further investigation. Most
often, high levels of TDS are caused by the presence of potassium, chlorides
and sodium. These ions have little or no short-term effects, but toxic ions
(lead arsenic, cadmium, nitrate and others) may also be dissolved in the water.
Why does this meter also check the salt content in the
water?
Salt water affects plant growth by actually dehydrating the
plant, which will kill it. The plant will have a burnt appearance if there is
too much salt water. There are some plants that grown in salt water though and
are not harmed by the salt.
Test Results:
TSD:
8/7/13 Field A Sample 1 = 2350
8/7/13 Field A Sample 2 = 2350
8/7/13 Field B Sample 1 = 2290
8/7/13 Field B Sample 2 = 2290
8/14/13 Field B Sample 1 = 2370
8/14/13 Field B Sample 2 = 2170
8/14/13 Field B Sample 1 = 2400
8/14/13 Field B Sample 2 = 2350
8/21/13 Field B Sample 1 = 2300
8/21/13 Field B Sample 2 = 2400
8/21/13 Field B Sample 1 = 2300
8/21/13 Field B Sample 2 = 2400
Conductivity
8/7/13 Field A Sample 1 = 3.3
8/7/13 Field A Sample 2 = 3.37
8/7/13 Field B Sample 1 = 3.43
8/7/13 Field B Sample 2 = 3.37
8/14/13 Field B Sample 1 = 3.3
8/14/13 Field B Sample 2 = 3.4
8/14/13 Field B Sample 1 = 3.43
8/14/13 Field B Sample 2 = 3.37
8/21/13 Field B Sample 1 = 3.45
8/21/13 Field B Sample 2 = 3.41
8/21/13 Field B Sample 1 = 3.28
8/21/13 Field B Sample 2 = 3.43
Salinity
8/7/13 Field A Sample 1 = 1620
8/7/13 Field A Sample 2 = 1780
8/7/13 Field B Sample 1 = 1850
8/7/13 Field B Sample 2 = 1780
8/14/13 Field B Sample 1 = 1620
8/14/13 Field B Sample 2 = 1620
8/14/13 Field B Sample 1 = 1740
8/14/13 Field B Sample 2 = 1740
8/21/13 Field B Sample 1 = 1660
8/21/13 Field B Sample 2 = 1660
8/21/13 Field B Sample 1 = 1590
8/21/13 Field B Sample 2 = 1660
Ammonia Nitrogen
Why is Ammonia-Nitrogen an indicator of Water Quality?
Ammonia-nitrogen is an inorganic, dissolved form of nitrogen
that can be found in water and is the preferred form for algae and plant
growth. Ammonia is the most reduced form of nitrogen and is found in
water where dissolved oxygen is lacking. When dissolved oxygen is readily
available bacteria quickly oxidize ammonia to nitrate through a process known
as nitrification.
Other types of bacteria produce ammonia as they decompose
dead plant and animal matter. Depending on temperature and pH (a measurement
of acidity), high levels of ammonia can be toxic to aquatic life. High pH
and warmer temperatures increase the toxicity of a given ammonia
concentration. High ammonia concentrations can stimulate excessive
aquatic production and indicate pollution. Important sources of ammonia
to rivers and ponds can include: fertilizers, human and animal wastes, and
byproducts from industrial manufacturing processes.
Test Results:
8/7/13 Field A Sample 1 = .10
8/7/13 Field A Sample 2 = .10
8/7/13 Field B Sample 1 = .25
8/7/13 Field B Sample 2 = .25
8/14/13 Field B Sample 1 = .25
8/14/13 Field B Sample 2 = .25
8/14/13 Field B Sample 1 = .25
8/14/13 Field B Sample 2 = .25
8/21/13 Field B Sample 1 = .10
8/21/13 Field B Sample 2 = .25
8/21/13 Field B Sample 1 = .10
8/21/13 Field B Sample 2 = .05
Nitrate-Nitrogen
Why Nitrate, Nitrite, and Nitrogen Are Important?
Nitrogen is one of the most abundant elements. About 80
percent of the air we breath is nitrogen. It is found in the cells of all
living things and is a major component of proteins. Inorganic nitrogen may
exist in the free state as a gas N2, or as nitrate NO3-, nitrite NO2-, or ammonia
NH3+. Organic nitrogen is found in proteins and is continually recycled by
plants and animals.
Environmental Impact:
Nitrogen-containing compounds act as nutrients in rivers. Nitrate reactions in fresh water can cause oxygen depletion. Aquatic organisms depending on the supply of oxygen in the stream will die. The major routes of entry of nitrogen into bodies of water are municipal and industrial wastewater, septic tanks, feed lot discharges, animal wastes (including birds and fish), as well as discharges from car exhausts.
Bacteria in water quickly convert nitrites to nitrates. Nitrites can produce a serious condition in fish called "brown blood disease." Nitrites also react directly with warm-blooded animals to produce methemoglobin. Methemoglobin destroys the ability of red blood cells to transport oxygen. Nitrite/nitrogen levels below 90 mg/l and nitrate levels below 0.5 mg/l seem to have no effect on warm water fish.
Test Results:
8/7/13 Field A Sample 1 = 1.0
8/7/13 Field A Sample 2 = 1.0
8/7/13 Field B Sample 1 = 0
8/7/13 Field B Sample 2 = 0
8/14/13 Field B Sample 1 = 1.0
8/14/13 Field B Sample 2 = 1.0
8/14/13 Field B Sample 1 = 1.0
8/14/13 Field B Sample 2 = 1.0
8/21/13 Field B Sample 1 = 0
8/21/13 Field B Sample 2 = 0
8/21/13 Field B Sample 1 = 0
8/21/13 Field B Sample 2 = 0
Low Range Phosphates
Why test low range phosphates?
According to the EPA phosphorus is a common constituent of agricultural
fertilizers, manure and organic wastes in sewage and industrial effluent. It is
an essential element for plant life, but when there is too much of it in water,
it can speed up eutrophication (a
reduction in dissolved oxygen in water bodies caused by an increase of mineral
and organic nutrients) of rivers and lakes. Soil erosion is a major contributor
of phosphorus to streams. Bank erosion occurring during floods can transport a
lot of phosphorous from the riverbanks and adjacent land into a stream.
Test Results
8/7/13 Field A Sample 1 = .2
8/7/13 Field A Sample 2 = .2
8/7/13 Field B Sample 1 = .2
8/7/13 Field B Sample 2 = .2
8/14/13 Field B Sample 1 = .4
8/14/13 Field B Sample 2 = .4
8/14/13 Field B Sample 1 = .4
8/14/13 Field B Sample 2 = .4
8/21/13 Field B Sample 1 = .8
8/21/13 Field B Sample 2 = .8
8/21/13 Field B Sample 1 = .4
8/21/13 Field B Sample 2 = .2
Sulfate
Why test for sulfate?
Sulfate is a compound found in nature. It occurs naturally in water in various amounts. If a high level of sulfate
is in water, the water may have a bitter taste. Sulfates are also found in minerals, soil, rocks, plants and food.
When the AFRI project was in the nursery stage we frequently smelled sulfur in the water inside the greenhouses. Now that all the rice is exposed to the air we hardly smell sulfate at all.
Where can sulfate be found and how is it used?
Sulfate is found in most fresh water supplies. Some regions have higher sulfate levels than others. In foods,
sulfate is present as the salts of sodium, calcium, iron, magnesium, manganese, zinc, copper, ammonium,
and potassium.
Test Results
8/7/13 Field A Sample 1 = 160
8/7/13 Field A Sample 2 = 200
8/7/13 Field B Sample 1 = 160
8/7/13 Field B Sample 2 = 180
8/14/13 Field B Sample 1 = 160
8/14/13 Field B Sample 2 = 160
8/14/13 Field B Sample 1 = 160
8/14/13 Field B Sample 2 = 180
8/21/13 Field B Sample 1 = 160
8/21/13 Field B Sample 2 = 120
8/21/13 Field B Sample 1 = 120
8/21/13 Field B Sample 2 = 160
Soil Testing
NPK Soil Kit
N= Nitrogen
P=Phosphorus
K=Potassium
pH Test was completed as well.
It is hard to list the results to these tests only listed letters with results on test cards. We'll take some time to go through these and post them and the card info in another post.
Air/Gas Tests
Gas test have been sent to UC Davis for analysis. Results will follow. In the picture above the white cone is a carbon unit that tests the inside of the unit for gas otherwise know as carbon.
The final test...
The last test is simply to check to make sure there is enough water in the field. Someone from the Delta Science Center committee checks the water level several times a week. At this point in the study keeping the field flooded is important. The above ruler shows us where the water level is at this time. Right now this is a good hight for this size field.
Already the main AFRI study on Twitchell Island has drained their water. The learning lab on Jersey Island will have to keep this field flooded for a few more weeks since we had so many problems getting the project going this year.
