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8/9/2019 Training Farm Desmons Crop Water Management Dr Ajay
1/14
9/9/20
AWATT Workshop on Water efficiency
and plant protection management for highvalue crop production
Dr. Ajay K JhaColorado State University
August 8-12
FAO Building, Kabul
Research and Demonstration
Appropriate TechnologyDissemination
Soil, Water Use andCrop Production
Soil, Plant and water: Agronomic Best Practices for
Sustainability of small farm production
Learning will occur by discovery and hands on
practical understanding
Emphasis on cropping systems
Natural Resources Evaluation
Soil, water, climate, and plants
Human Resources Evaluation
Labor needs and supply, knowledge and experience
Market Evaluation and Trends in other parts of the
world and neighboring countries
Demonstrations a way to promote new
technologies.
Adoption and dissemination of agronomic
practices are the hardest steps in extension work
Adoption of new management and production
practices is key in maintaining profitable farming
operations
Even if information is readily available, many
farmers may be reluctant to adopt new
methodology directly from research sources
A very large disconnect exists between thetransfer of information from researcher to
producers
How You Will Learn ?
Personal discovery and research
You need to ask a lot of questions
Group discussion
,instructors, and participants
Everyone must be involved
Presentations
All course participants will give a presentation duringthe course for their plan on demonstration andtechnology transfer.
Lesson Learned from Last
Workshop
The plans of 4 group plans are?
New 5th group
Level of understanding on irrigation methods and
Lesson Learned from Last
Workshop
water management at field level
Small farm adoption of irrigation system and
evaluation of ongoing activity
Learning, evaluation of technology, adoption at
research and on farm site and strategy for
dissemination
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How Will Work
Each group will beassigned to adapt
technology in their
IndividualGroup
demonstration
Soil and WaterResources
Soil fertility
CropManagement
Plants andplanting
BusinessManagement
Labor
dissemination strategy
to farmers field and
measure success
through the
replication of these
farms.
Water andirrigation
Crop rotations
Pestmanagement
Harvest andStorage
Marketing
Accounting
How the Group Plan will work
Group will meet every month after workshop and
work on their demonstration planConnect with AWATT Farm Manager Naqib
Re lication and sustainabilit is im ortant fordemonstration and tech transfer
The group will give a short overview of theirtechnology adoption and dissemination strategy at theend each cropping season.
On-farm demo at farmers plots of each group needs tobe connected with AWATT Badham BaghDemonstration and other regional farm
Adoption and dissemination of
technologies at Farmers plot
Owner:
Location:
Type of farm:
What crops? Irrigation
systems and methods,
plant protection
Strategy of disseminations ra egy
How to monitor and
evaluate? What
intervention required
and when?
Assignment of SpecializationsOn farm
demonstration
Soil and WaterResources
CropManagement
Plants and
BusinessManagement
Soil fertility
Water andirrigation
planting
Crop rotations
Pestmanagement
Harvest and
Storage
Labor
Marketing
Accounting
Assignment of Specialization
Group 1: vegetable
production in villages
as kitchen garden.:
Group 4: Drip
irrigation and mulch
(2009),Tomato
certified variety vs.
arwan
Group 2:
Flood/Furrow : Sweet
Corn: Darul Aman
Group 3: Winter
Wheat with flood and
furrow (2009-10-
potato): Bamian
irrigation system
(2009-2010). Qargha
Group 5: new project
decide and present.
Balkh and Nangarhar,
Kapisa and Kabul:
Tomato & other crops
Soil, Water and Nutrition
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Climate
Precipitation
Weathering, leaching
Controls biological activity
Rate control on biochemical activity
Climate influences
vegetation and vegetation influences soil formation
Available water Vs. plant requirement
Biological Activity
Plants
Microorganisms
insects, worms, animals, weeds
Nutrient cycling
Strong interaction with climate!
Feed back loops
Grass prairie>high water capture, little leaching>deep
organic matter accumulation
Topography
Hydrology
Soil movement
Erosion surface
Depositional surface
Microclimate of soil and plant
Time
Profile development
Accumulation
A horizon accumulated
or anicmatter
B horizon accumulates
carbonates, clay, etc.
Losses
A horizons loose clay,
carbonates
Soil properties
Understanding soil properties leads to improved
crop management
Soil texture
Soil structure
Organic matter
Soil texture
Relative amounts of
Sand
Silt
Clay
Controls
Density
Hydraulic properties
American system of soil textural classification
http://www.pedosphere.com/resources/bulkdensity/index.html
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Soil Coloring
Material Chemical Composition Color
Manganese Mn02 Purplish Black
Hematite Fe203 Red
Geothite FeOOH Yellow
Hydrated Ferric Oxide Fe(OH)3*nH20 Red Brown
Calcite CaC03 Whitish
Glauconite KMg(Fe,Al)(SiO3)6.3H2O Greenish
Soil Structure
Formation of soil particles into aggregates
Largely affected by soil management
Important for
Plant growth
Soil water relations
Resistance to soil erosion
Horizonation
Changes in soil properties
with depth
Soil managers must
understand what is below
the surface
Irrigation and hydraulic
properties affected by
textural changes (i.e.:
clay pans)
Organic Matter in Mineral Soils
Air
Mineral
Organic
Water
Small proportion of total soil
Huge impact on soil properties
1/3 or more of cation exchange capacity
Stability of soil aggregates
Energy supply
Nutrient supply
Sources of Soil Organic Matter
Plant residues (roots, shoots)
All other sources are secondary
Microorganisms Bugs, worms
animals
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Organic Matter and Soil Properties
Nutrient retention and supplyWater retention and availability
Cation exchan e ca acit
Buffering capacity
Soil structural development and stability
Biological activity and diversity
C:N Ratios
Typical C:N Ratios
Soil 8:1 to 15:1
10:1 most common
Plants
Legumes 20:1 to 30:1
Small grain straw 100:1
Animal manures20:1 to 30:1
Microbes
4:1 to 9:1
Bacteria lower (more protein) than fungi and others
Cropping Systems and Soil Organic
Matter
Two Controlling Processes
Production of Organic Residues
Decomposition of Residues and Organic Matter
For each element of a system, we must consider how it affects
both processes
For example, how would these affect the processes?
Crop Rotation
Tillage Practices
Fertilizer inputs
Irrigation practices
Crop Rotation and SOM
Plant Species affects SOM in three ways
Amount of Biomass Returned
Harvested parts
ompos t on
Applying Organic Materials to Soils
Livestock manures
Biosolids
Green manures and cover crops
Benefits Chemical and physical affects
Increase soil organic carbon content
Fertility value
Increased microbial activity
Increased crop production
Problems Expensive to transport
Odor
Weed seeds
Toxic compounds/salts
Review Soil Water Principles
MineralPore
Space
Where is water storedin the soil? Pore spaces
Pores vary in size and
Organic
2%
50% s ape micropores
macropores
Water retentiondepends on pore size
Soil texture andstructure determinepore size distribution
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Soil Water
1. Hygroscopic water Microscopic film of water surrounding soil particles
Strong molecular attraction; water cannot be removed by natural forces
Adhesive forces (>31 bars and upto 10,000 bars!)
2. Ca il lar water
Three categories
. Water held by cohesive forces between films of hygroscopic water
Can be removed by air drying or plant absorption
Plants extract capillary water until the soil capillary force is equal to theextractive force Wilting point: soil capillary force > plant extractive force
3. Gravity water Water that moves through the soil by the force of gravity
Field capacity Amount of water held in the soil after excess water has drained
is called the field capacity of the soil.
Irrigation Principles Grain CropsExample - Corn
Know water needs as crop develops
Week Growth Weekly ET (in)
1, 2 -4 leaf .8
3, 4 4-8 leaf 1.4
- .
6 10-12 leaf 1.4
7 12-14 leaf 1.4
8 14-16 leaf 1.5
9 Pollination 2.3
10 Pollination 2.3
11 Grain Fill 1.8
12 Grain Fill 1.8
13 Grain Fill 1.8
14 Grain Fill 1.7
15 Grain Fill 1.7
16, 17 Maturity 3.2
Irrigation Scheduling
Irrigation scheduling is the decision of when and
how much water to apply to a field.
Irrigation scheduling saves water and energy.
Indicators
All irrigation scheduling procedures consist of
monitoring indicators that determine the need for
irrigation.
Scheduling Methods
Hand feel method
Distribute NRCS Feel Method Handout
Practice if time allows
Gravimetric Soil Moisture Sample
Tensiometers
Demonstration
Water budget approach
Typical available water holding
capacities based on soil texture.
Table 1: Typical available water holding capacities based on
soil texture.
Te xtural c lasses Avail able water in inches/f oot*
of depth
Coarse sands 0.60-0.80
Fine sands 0.80-1.00Loamy sands 1.10-1.20
Sandy loams 1.25-1.40
Fine sandy loams 1.50-2.00
Silt loams 2.00-2.50
Silty clay loams 1.80-2.00
Silty clay 1.50-1.70
Clay 1.30-1.50
*To convert to metrics, use the following equivalents: 1 inch = 2.5
centimeters; 1 foot = 30 centimeters.
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Limited Irrigation
Limited irrigation is a form of deficit irrigation that
seeks to maximize water productivity through
timing of irrigation applications at critical crop
growth stages and through managed soil
depletions for systems with less than adequate
capacity or limited quantities of water.
Limited Irrigation Systems
Limited irrigation systems incorporate practices thatreduce consumptive water use (ET) through acombination of practices
crop rotations with different water use patterns
lower water use crops
cultural practices that conserve water
conservation tillage
reduced plant populations
weed and pest control practices
improved irrigation efficiency
variety selection
Cultural Practices
Weeds, Disease
Soil fertility
Frost, Heat, Salinity
va uate y e per un t o water use
Reduce direct evaporation from soil surface
Conservation tillage
Water logging Evaluate yield per unit of water
used
Reduce direct evaporation from soil surface Conservationtillage
40m
Channel
Chili Pepper Tomato Corn
40 m 40m
AWATT Research and Demonstration
Flood Furrow Flood Furrow Flood Furrow
D12 : Unlevelled Plot
Total Length of D12 (Unlevelled Field) = 120 m
Total Width of D12 (Unlevelled Field) = 36m
Total Furrow Area for D12 (Unlevelled Field) = 2160 sq.m
No of bedsin D12 (Unlevelled Field) = 36
Bed Length = 35m
Bed Width = 75 cm
Total Flood Area for D12 (Unlevelled Field) = 2160 sq.m
Chilli Pepper Tomato Corn Tomato Chilli Pepper Corn
Channel
45m
AWATT Research and Demonstration
Fl ood Furrow Fl ood Furr ow Fl ood Furrow
15m 15m 15m 23.5m 23.5m 23.5m
D13:Leveled Plot
Total Length of D13 (Levelled Field) = 116 m
Total Width of D13 (Levelled Field) = 36m
Total drip area of D13 (Levelled Field) = 1620 sq.m
Total Furrow Area of D13 (Levelled Field) = 1269 sq.m
Total Flood Area of D13 (Levelled Field) = 1269 sq.m
No. of bedsin D13 (Levelled Field) = 42
Length of bed = 35 m
Width of bed = 75 cm
Total Area(Sq.m) 4176
Drip Irrigation
Nee de d Ite ms Ar ea(s q.m ) Row x Row dis tance (cm ) Plant x Plant distance (cm )
Sweet Corn Seed 2713 70 25-30
-
Chili Pepper 2713 70 20-25
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Soil components
A. Solids
1. inorganic particles =sand, silt, clay
diameter:
clay < 0.002 mm
silt 0.002 to 0.05 mm
sand 0.05 to 2.0 mm
2. organic matter
B. Fluids
1. Water (moisture)
2. AirSource:http://soils.usda.gov/education/resources/k_12/lessons/profile/
Depth of water (dw)
Drz= da+ dw+ ds1 unit area
dw
da
What about volumes?
Source:http://soils.usda.gov/education/resources/k_12/lessons/profile/
Drz
ds
Drz
= depth of root zone
da
= depth of air
dw= depth of water
ds= depth of solids
Assuming a unit area, all water balance
components can be expressed as depths of
water.
P = precipitation
ETIrrP
RO
Irr = irrigation
ET = evapotranspiration
RO = surface runoff
Source:http://soils.usda.gov/education/resources/k_12/lessons/profile/
I
S
D
= n ra on
D = drainage
S = storage (dw)
All components can also
be expressed as fluxes(depth/area/time).
L = lateral flow
L
C
C = capillary rise
Field capacity (FC)
Moisture content that the soil can hold against
gravity
Water in the soil after the excess water has been
drained; commonly assumed to be at 1/3 bar soil
moisture tension (SMT)
Permanent wilting point (PWP)
Soil moisture content at which a plant
permanently wilts
Normally approximated at 15 bar SMTActually varies with plant species and soil
physical properties
Basic Principles:
Irrigation Scheduling
This is the decision of when and how much water toapply to a field
Irrigation scheduling will save water pumping costs,an a or
Minimizes crop water stress
prevents over- and under-irrigation
Increases production
Helps to control salinity
There are several tools to help you to judge the soilmoisture content
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Basic Irrigation Principles and
Management
When is it time to
irrigate?
Usually when your soil is0.25
0.3
0.35
0.4
volume)
Available Water
Field Capacity
This is hard to tell
look for grasses that dont
spring up when stepped on
soils will usually hold
together fairly well when
adequately moist
if starting to crumble,
plan to irrigate soon
0
0.05
0.1
0.15
0.2
S and Sandy
Loam
Loam Silt
Loam
Clay
Loam
Silty
Clay
Clay
Finer Texture
WaterContent(%
Wilting Point
Unavailable Water
Graphic courtesy of Living on the Land, OSU Extension Service
The look and feel method
Dig down to the root zone of a crop/pasture and pick up ahandful of soil
Generally, if the soil holds together, there is adequate moisture
Photo courtesy of Living on the Land
Look and Feel:
Clay, clay loam, orsilty clay loam at 25-50% moisture
Clay, clay loam, orsilty clay loam at 50-75% moisture
Irrigation is overdue Will need to irrigate
soon
Photos courtesy of Living on the Land, USDA NRCS
Look and Feel:
Sandy loam or finesandy loam at 25-50%moisture
Sandy loam or finesandy loam at 50-75%moisture
Irrigation is overdue Will need to irrigate
soon
Measuring soil moisture.
Measuring soil moisture for growing purposes is
typically done in one of two ways:
a. o ume r c measuremen , e percen age o
water in a given amount of soil.
b. Tensiometric measurement, the physical force
actually holding water in the soil, measured in
Centibars (or kPa) of soil water
Soil Moisture Measurement
Tensiometer: direct measurement of soil water
tension, which is the tension all root systems must
overcome to extract water from the surrounding
so .
The Watermark sensor (granular matrix sensor)
calibrated method of measuring soil water, an
electrical resistance type sensor, read by Soil
Moisture Meter which converts the electrical
resistance reading to a calibrated reading of
Centibars (or kPa) of soil water tension.
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Why to use Tensiometer
Amount of water is not as important as how
difficult it is for the plant to extract it from the soil
Soil water tension (or metric potential) has to be
overcome for the plant to move water in to its root
system
Different soil types will have different tensions
even at the same volumetric measurement, making
volumetric information relative to local conditions
and often requiring site calibration for reading
equipment.
Soil-water tension and availablewater holding capacity (the amount
of water held in the root zone).The % shown are Available WaterHolding Capacity depleted.Tension value is appropriate todetermine when water needs to bereplenished.Irrigations are scheduled when50% of the available water hasbeen depleted (MAD orManagement Allowable Depletion).Soil water tension measurementis what really determines the
availability of moisture for plantmaterial
Typical Available Water-Holding Capacity
Soil Texture mm Available Water
Coarse Sand 15-20
Fine Sand 20-25
Loamy Sand 28-30
Sandy Loam 32-36
-
Loam 56-64
Silty Loam 51-64
Silty Clay Loam 46-51
Silty Clay 38-43
Clay 33-38Source:SCS ColoradoIrrigation Guide, 1988.
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General Estimates for Common High Value Crops
Crop Crop water need (mm/total growingperiod)
Beans 300 - 500
-
Maize 500 - 800
Sorghum/
millet
450 - 650
Soybean 450 - 700
Sunflower 600 - 1000
Crop water Requirement
Crop water requirements, irrigation systems and
schedules maximizes crop growth and waterefficiency
It reduces nutrient leachin and water ollution
caused by runoffa better utilization of scarce
water resources.
3 factors which determine the amount of water
that a crop requires:
The climate in which the crop is grown
The crop type that is grown
The development stage that the crop is in.
Crop water Requirement
Local climate conditions, crop development stage
and season, soil properties to design an irrigation
system and schedule.
This allows for cultural practices designed to
maximize crop water use efficiency.
Crop Evapo-transpiration rate (ETo)
Transpiration
The pan evaporation method is obtained by directlymeasuring the evaporation rate from an evaporatingpan. The standard for this pan is a circular pan withdiameter of 1.21 m and depth of 25 cm placed 15cm above the soil surface.
Crop water Requirement
To use the pan, water is filled to 5 cm below the rim,and then water is allowed to evaporate over thecourse of a day. Measurements are taken at a set
time every day and daily rainfall is monitored aswell. With this size pan, the amount of water thathas evaporated (Epan) is the difference between thetwo measured water depths (after taking rainfall intoaccount).
Efficient Irrigation technology
(Water Use at the Farm)
Land preparation,
Crop selection and
management,Irrigation scheduling
Water application
Discharge flow
measurement
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Benefits
N fixation with legumesImprove soil tilth and H2O infiltrationReduction of nematodes and disease
ee suppression controN sequestrationBeneficial arthropod habitatOrganic certification land use plansC banking
Crop Per drop
Maximize Income per unit water use
Maximize Yield per unit water
Maximize effectiveness of rainfall and irrigation
Maximize Crop Value
Minimize Production Costs
Increase Flexibility
Reduce Risk
For Success
Timing
Good seed quality
nocu ate w t appropr ate nocu ums
Good seed bed
Weed control
Irrigate
Appropriate mixtures of species/cultivars
Fertilize
PLUGS
High Quality Seedling nurseryIrrigation system design
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Strategic thinking & planning ahead
What I am good at?
How do I plan ?
What are the options for successful planning?
What can go wrong?
How to create a team?
What is the level of coordination, cooperation and
communication exist with stakeholder and work?
What way successful for implementation?
Strategic thinking !
Suggested Additional Outlet on Island
Continuation of Knowledge
Promote appropriate technology to farmers field
for increasing productivity, income for Afghan
livelihood