SOIL AND WATER QUALITY
MONITORING TECHINIQUES
Ramesh Kanwar
Professor and Chair, Agricultural & Biosystems Engineering Department
Iowa State University, Ames, Iowa USA
Objectives of Soil and Water
Monitoring
1. To determine the impact of any activity on
the landscape (agriculture, chemicals,
manure use, industry, human or industry
waste etc) on surface or groundwater
quality
2. To make sure our drinking water supplies
are safe for human consumption.
World Water Supply
2.8% Fresh
0.01% in surface
waters & the
atmosphere
0.307% in Ground
Water < 0.5mi deep
0.307% in
Ground
Water >
0.5mi deep
0.005% soil
moisture
97.2% Saline
2.15% Icecaps
& Glaciers
Water Quality Issues Related to Human
Health
 Main compounds are - N, P, pathogens, and antibiotics
 Surface and groundwater pollution potential
 High NO3-N levels can cause blue baby syndrome
(methemoglobinemia)
 High NO3-N can lead to etiology of stomach cancer (only
limited evidence available)
 Bacteria and pathogens can be disease causing
 Antibiotics as feed supplements are finding ways to water
WATER QUALITY CONCERNS
FROM ANIMAL WASTES
• Main concern is infant health
– Nitrate/nitrite causes “blue baby” disease
– Newborn babies essentially suffocate
– Water Quality Standard for Nitrate-nitrogen is 10 mg/l
• SURFACE WATER WATER BODIES:
– Ammonia > 2 mg/L Kills Fish
– Phosphate > 0.05 mg/L promotes excess algae growth which
leads to Fish Kills - Eutophication
– BOD depletes oxygen which causes Fish Kills - Hypoxia
Agricultural Contribution: World Perspective
• 60% N and 25% P from European Ag to
North Sea
• 48% of nutrient pollution in the former
Czechoslovakia
• Significant levels flowing into the Adriatic
Sea
• Eutrophication problems in Lake Erie
NITROGEN LOSSES FROM FARMS IN THE
MISSISSIPPI BASIN – US Example
Percent Losses
Agricultural Fertilizer
55%
Nitrogen from Crops
25%
Non-ag fertilizers 3%
Deposited by rain 15%
Human Sewage 2%
Water Quality Issue: HYPOXIA
• The worst hypoxic conditions are in the
Baltic Sea and the Black Sea
• Hypoxic conditions have been increasing
since the 1960’s
• The Gulf of Mexico, outside the delta of
the Mississippi River is the worlds third
largest hypoxic area
• 12400 sq. km. (4800 sq. mi)
Major Water Quality Issue: WORLD HYPOXIC
ZONES
Total Nitrogen (ppm)
12
Crystal Lake
10
8
6
4
2
0
Slip
Bluff Lake
Little
Park
Lake
West Sioux
Okoboji
Lake
Arrowhead Lake
Lacey
Keosauqua
Green
BeltLake
Lake Park Lake
Big
NineSpirit
Eagles
Lake
Willow
Lake
Lake
Wapello
Crawford
Creek Impoundment
Mitchell Lake
Storm
Lake (incl
Little Storm Lake)
Moorehead
Lake
Green
Castle
Lake
Yellow Smoke Park Lake
Red Haw Lake
Pleasant
Creek
Kent
ParkLake
Lake Lake
Oldham
Otter
Creek
Lake
Lake
McBride
Springbrook
Lake SugemaLake
Lake
Anita
Easter
LakeLake
Greenfield
Mormon
TrailLake
Lake
East Okoboji
Three Mile Lake
George
Wyth Lake
South
Prairie
Lake
Blue Lake
Mill
Creek
(Lake)
Lake
of
the
Hills
Hooper
AreaLake
Pond
Hawthorne
(aka Barnes City Lake)
Browns
Lake
Manteno
Lake
Twelve
Mile
Lake
Beaver Lake
Meyers Lake
Arrowhead Lake
Arbor
Lake (Lake)
Dog Creek
Viking
Lake
Upper
Gar
Lake
DeSoto
Bend
Lake
Spring Lake
West
Osceola
Lake
Icaria
Thayer
LakeLake
Dale Maffitt
Fogle
Lake
Lake Orient
Lake Minnewashta
Hannen Lake
Rathbun
Avenue
ofLake
theLake
Saints Lake
Prairie
Rose
Lake
Cornelia
Pierce Creek Lake
Roberts
Creek
Lake
Pollmiller
Park
Lake
Lower
Gar
Lake
Lake Iowa
Five
Island
Nelson
ParkLake
Lake
Indian Lake
Lake of Three Fires
Ottumwa
Lagoon
Lake
Manawa
Cold
Springs
Diamond
LakeLake
Lake
Keomah
Lake
Pahoja
Little
River
Central
Park Lake
Bob
White
Lake
Badger
LittlefieldCreek
LakeLake
Lake Geode
Clear
Lake
Casey
Lake
Hickory Hills Lake)
Wilson
Park (aka
Lake
Green Valley
Lake
Lake
Ahquabi
Lost
Island
Lake
Windmill
Lake
Big
Creek
Lake
Meadow Lake
Little
Spirit Lake
Silver
CenterLake
Lake
Silver Lake
Silver
Lake
North
Twin Lake
Rock
CarterCreek
Lake Lake
Williamson
Pond
Lake
Miami
Swan
Lake
White Oak Lake
Tuttle
Lake
Black
Hawk
Silver
Lake Lake
Lake Smith
Lake Darling
Crystal Lake
Lake
Meyer
Little Wall
Lake
Mariposa
Lake
Ingham
Lake
East
Lake
(Osceola)
Union
Grove
Lake
Hickory
Grove
Lake
Don
Williams
Lake
Trumbull
Lake
Volga
Lake
Briggs Woods Lake
Lower Pine Lake
Lake Hendricks
Rodgers
Park
Lake
Red Rock
Lake
Coralville
Lake Lake
Upper
BrushyPine
Creek Lake
Eldred
Sherwood Lake
Beeds Lake
Saylorville Lake
14
Badger Lake
Current Status of Iowa Lakes
Mean total nitrogen for Iowa lakes sampled three times during summer, 2000
(Downing and Ramstack 2001)
Proposed
benchmark:
700 ppb
Clear Lake
Manure Characteristics and Production
Estimates
( what does it contain)
6% of bodyweight per day
(most species)
13 - 15 % solids
85 -87% liquid
Daily Manure Production Per
Animal
• We have estimates of manure production
– 4.5 kg/day/hd for swine (liquid manure)
– 45-50 kg/day/hd for dairy cow (liquid)
– 25-30 kg/day/hd for beef cow (liquid)
• Solid portion ~ 13-15% of total
Animal Waste Nutrient Utilization Scenario
•
•
•
•
•
•
Swine Confinement Facility
4000 animals @ 61 kg / animal
Nutrient Content in kg/ day / 1000 kg
0.52 kg N / day / 1000 kg animal wt.
0.18 kg P / day / 1000 kg animal wt.
0.29 kg K / day / 1000 kg animal wt.
Manure Characteristics
• In general…
– Nitrogen (ammonia) is in urine
– Phosphorus is in feces
• In the U.S. we’re working on
ways to keep urine and feces
separate
Manure Management Issues
 Animal manure is a liability in high density
livestock production areas where fertilizers are
cheap
 Animal manure is an asset if fertilizers are
unavailable or expensive
 Odor and ammonia emission to air-global warming
 Odor issues are serious in residential areas
 Pollution of soil and water resources-water quality
 Hypoxia problems in international water
Nitrogen
• Is mobile in some forms (NO3)
– not in others (organic, NH4)
• Does not carryover like P
• Is not determined by soil test
Negative Environmental
Impacts
•Nitrogen
•
•
•
- Nitrates leaching to tilelines and/or
groundwater
- Ammonia runoff into surface water
causing fish kills
Negative Environmental
Impacts
•Phosphorus
•
•
Loss with soil erosion
Eutrophication (algae growth) of
surface waters
Phosphorus
•
•
•
•
•
Is bound to the soil particles
Remains in the soil year to year
Moves if soil erodes
Is determined by soil test
Does not volatilize like nitrogen
Manure Nutrient Planning
Determine the hectares needed to
maximize nutrient use and minimize
negative environmental impacts
Question 1
Which Nutrient should I use
for planning...
Nitrogen?
Phosphorus?
U.S. Manure Law says...
•Use nitrogen for nutrient planning
•
- Results in least land area needed
•
- May not be best use of nutrients
because phosphorus is overapplied
•
- Laws in U.S. are changing to require
P planning
•
N:P Ratio of Manure
•N:P ratio is different for different types of
manure
•
N:P
•Cattle ratio…
~ 2:1
•Swine ratio…
~ 1.5:1
•Poultry ratio…
~ 1:2
Phosphorus Planning
•Requires more hectares
•Results in lower application rates
•Maximize economic value of manure
•Depends on crop & manure application
frequency
•Requires additional commercial N
fertilizer
Question 2
How much of the nutrient
should I apply??
Plant Nutrient Utilization
•Plant utilization
– Corn uses 0.7 lb/bu N
– Beans use 3.8 lb/bu N
0.4 lb/bu P2O5
0.8 lb/bu P2O5
•Plant fertilization
– Corn needs 1.2 lb/bu N
– Beans need 0.0 lb/bu N
0.4 lb/bu P2O
0.8 lb/bu P2O
Steps in Manure Nutrient
Management
•1. Determine crop nutrient needs
•2. Determine manure nutrients available
•3. Calculate hectares needed for the
manure
•4. Calculate manure volume to apply
Summary - Manure Planning
•Not difficult to do
•Economically advantageous
•Manure can replace purchased
fertilizer
•Using manure correctly is good for the
environment
Potential Pathways
Pollutant
Pathway
1. Nitrate – N
Leaching & Runoff
2. Ammonium – N
Surface water runoff &
Aerial deposition
• Phosphorus
runoff
• Pathogens
runoff
• Organic Matter
runoff
Surface water
Surface water
Surface water
Soil and Water Quality
Monitoring Techniques
•
•
Soil sampling
Surface water sampling
•
•
•
•
•
•
•
Surface runoff
Open ditch or irrigation canals
Small or large rivers
Ponds, lakes, reservoirs
Ocean, sea
Wetlands
Groundwater
•
•
Shallow groundwater
Deep groundwater
Soil Monitoring and Sampling
•
•
•
•
•
•
Must know the objectives why to sample?
What to sample for?
When to sample?
Number of soil sampling?
Variability in sampling?
From various soil depths – Objectives?
Soil Monitoring
• What to sample for?
• NO3-N, pesticides, organic matter, metals,
organics, pathogens, micro-organisms, N, P,
K, micro-nutrients.
When to Sample?
• Once a week, month, or year.
• As a function of cropping system or
season.
• As a function of weather cycle.
Number of samples per field –
function of cost?
• Spatial variability.
• Minimum three samples per plot.
• Several depths.
• Composite to cut down cost.
Soil Sampling Techniques
•
•
•
•
•
Soil augers
Soil probes
Back saver
Zero contamination tube
Hydraulic probes
Problems During Soil Sampling
and Transportation
•
•
•
•
•
Cross-contamination
Separation, collection
Storage, transportation, temperature control
Timely analyses in lab
Laboratory techniques/interpretation
Quantity Control/Quality
Assurance
• Sending duplicate samples to recognized
laboratories
• Manual on laboratory procedures
• All steps on how to collect soil samples
and lab analyses.
Water Quality Monitoring
•
•
Point sources of pollution (manure storage
platforms, spills)
Non point sources (agriculture)
Monitoring Needs
•
•
Surface water
Groundwater
Surface water
Monitoring
•
•
•
•
•
•
•
Field runoff
Open ditches/drains
Irrigation canals
Ponds/Lakes/reservoirs
Wetlands
Streams, rivers (Danube River)
Ocean, Sea (Black sea)
Groundwater Monitoring
•
•
•
•
At what depth would you like to collect
water samples?
Shallow depth < 3 m.
Deep groundwater > 3 m.
Monitor at depth increments 5, 10, 15, …
50 m??
Groundwater Monitoring
Techniques
•
•
•
Piezometers
Water table wells
Deep ground water wells
Construction of Groundwater
Wells
2. Glass bottles VS plastic bottles.
3. Temperature control during transportation.
4. Acidify samples if used for NO3-N
analysis.
5. Store samples at 4oC until analyzed.
6. EPA protocol is to analyze within 15 days
of collection.
When to collect Groundwater
Samples?
• Weekly, monthly, 3-4 time in a year??
• Define objectives
• For drinking water wells – weekly/monthly
(weekly for public wells, monthly/six month for industrial
wells)
• Quality VS quantity
Vadose Zone Monitoring
• Water content and Chemical conc.
•
•
•
•
•
Soil moisture potential – Tensiometers
Soil water contents
Soil salinity
Temperature
Soil pore water sampling
Soil Pore Water Sampling
• Soil samples
Extract them for either NO3-N or pesticides
• Suction lysimeters
• Caissiosn lysimeters
• Trench lysimeters
• Drainage systems
• Piezometers
• Single or multiple sampling wells