effects of limiting water on growth, development and yield of alfalfa grown in the big horn basin,...
DESCRIPTION
My defense of my Masters Thesis workTRANSCRIPT
Effects of Limiting Water on Growth, Development
and Yield of Alfalfa (Medicago sativa L.)
Grown in the Big Horn Basin, Wyoming
Caleb Carter, M.S. Candidate
Outline
• Importance of alfalfa
• Agricultural water use
• Objectives
• Methodology
• Results
• Conclusions
A. Polvere, 2012
Alfalfa (Medicago sativa L.)
• Queen of forages
• Introduced to U.S. around 1850
• C3 perennial legume
• Has a high water use
(California Alfalfa and Forage Association, 2004)(Russelle, 2001)
Alfalfa Production in Wyoming
0
250
500
750
1,000
1,250
1,500
1,750
1950 1960 1970 1980 1990 2000 2010Pro
du
ctio
n (
t y-1
x 1
00
0)
Wyoming Crop Production
Alfalfa
Hay
Corn
Sugarbeet
Wheat
0
300
600
900
1,200
1,500
1,800
1950 1960 1970 1980 1990 2000 2010
Rev
en
ue
($
x 1
00
,00
0)
0
50
100
150
200
250
300
350
1950 1960 1970 1980 1990 2000 2010
Ha
Har
vest
ed
(x1
00
0)
Year(USDA NASS, 2012)
Municipal, Industrial, etc., 15%
Agriculture, 85%
(USDA NASS, 2012)
Definitions• Evapotranspiration (ET) – The sum of
evaporative losses of water from the soil surface (evaporation) and from the canopy (transpiration).
• Reference evapotranspiration (ETo) –. Evapotranspiration rate from a reference surface not short of water. Usually a hypothetical alfalfa or grass plant with specific characteristics.
• Crop evapotranspiration (ETc) – (Same as crop water use) Evapotranspiration from excellently managed, large, well-watered fields that achieve full production under the given climatic conditions.
• Water Use Efficiency (WUE) – Ratio between yield and the amount of water used to produce that yield.
𝑊𝑈𝐸 =𝑒𝑐𝑜𝑛𝑜𝑚𝑖𝑐 𝑦𝑖𝑒𝑙𝑑
𝑤𝑎𝑡𝑒𝑟 𝑢𝑠𝑒𝑑 (𝐸𝑇𝑐)A. Polvere, 2012
Study Objectives
1. Determine alfalfa’s water use (ETc) and water use efficiency (WUE) for conditions in the Big Horn Basin, Wyoming.
2. Quantify the effects of limiting water on the growth and forage quality of alfalfa.
3. Determine the economic impact of irrigation scheduling recommendations.
METHODOLOGY
UW Research and Extension Center, Powell, WY (PREC)
• 44° 45‘ 30” N, 108° 46‘ 36” W, 1344 masl
• Mean air temp: 8 to 10 °C
• Rainfall: avg. 173 mm
• 125 days frost free period
• Well drained Garland Loam (Fine-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Typic Haplargids)
Experimental Design:Strip Plot – planted June 7, 2011
Neutron probe acces tube WatermarksShaw Mountaineer Lander
-------------------------------- 6.75 m --------------------------------
Zone 13
---
----
-- 1
1.5
m -
----
----
---
----
----
----
----
----
----
----
----
----
----
----
---
46
m -
----
----
----
----
----
----
----
----
----
----
----
----
-
43 2 3 4 51 8 9 10 116 79 10 11 12
------- 2.25 m --------
1 5 6 7 82 12111 2 3 4 5 6 7 8 9 10 6 71 2 3
Ro
ad
Zone 14 Zone 15 Zone 16
0.25ETc 0.50ETc 0.75ETc 1.00ETc
10 11 128 9412 5
Main treatments – Irrigation: • 6.75 m wide x 46 m long• 1.0 ETc, 0.75 ETc, 0.5 ETc and
0.25 ETc
Sub treatments – Alfalfa Varieties: • 2.25 m wide x 11.5 m long• Shaw, Lander and Mountaineer
Irrigation
• Subsurface Drip Irrigation (SDI)• Computerized control • 16 independent zones • Fertigation
Alfalfa Cultivars
Lander
Developed: • University of
Wyoming
Characteristics: • Resistant to
Brown Root Rot
Fall Dormancy: 3
Shaw
Developed: • Montana State
University/ NRCS Bridger Plants Center
Characteristics:• Dryland variety
Fall Dormancy: 3
Mountaineer
Developed : • Forage Genetics
International, Nampa, Idaho
Characteristics:• Multifoliate leaf
expression
Fall Dormancy: 4
(Ditterline et al., 2001)(R. Groose, 2008)
Automated Weather StationUW Res & Ext Center, Powell, WY
www.WAWN.netETo Calculation using the ASCE Modified Penman Monteith Equation
ASCE EquationETo=
0.408∆ Rn−G +γ𝐶𝑛
T+273U2 es−ea
∆+γ 1+𝐶𝑑U2Where:• ETsz = standardized reference crop evapotranspiration for short (ETos) or tall (ETrs) surfaces
(mm d-1 for daily time steps or mm h-1 for hourly time steps),• Rn = calculated net radiation at the crop surface (MJ m-2 d-1 for daily time steps or MJ m-2 h-1
for hourly time steps),• G = soil heat flux density at the soil surface (MJ m-2 d-1 for daily time steps or MJ m-2 h-1 for
hourly time steps),• T = mean daily or hourly air temperature at 1.5 to 2.5-m height (°C), • u2 = mean daily or hourly wind speed at 2-m height (m s-1),• es = saturation vapor pressure at 1.5 to 2.5-m height (kPa), calculated for daily time steps as
the average of saturation vapor pressure at maximum and minimum air temperature,• ea = mean actual vapor pressure at 1.5 to 2.5-m height (kPa),• ∆ = slope of the saturation vapor pressure-temperature curve (kPa °C-1), • γ = psychrometric constant (kPa °C-1),• Cn = numerator constant that changes with reference type and calculation time step (K mm s3
Mg-1 d-1 or K mm s3 Mg-1 h-1) and• Cd = denominator constant that changes with reference type and calculation time step (s m-1).• Units for the 0.408 coefficient are m2 mm MJ-1.
(ASCE-EWRI, 2005)
Irrigation Calculations
• Crop water use (ETc): 𝐸𝑇𝑐 = 𝐾𝑐 × 𝐸𝑇𝑜
• Available Water (AW): 𝐴𝑊 = 𝐹𝐶 −𝑊𝑃
• Plant Available Water (PAW): 𝑃𝐴𝑊 =𝐴𝑊 × 𝑅𝑍
• Allowable Depletion (AD): 𝐴𝐷 = 𝑃𝐴𝑊 ×𝑀𝐴𝐷
• Soil moisture depletion = PAW – ETc
• Irrigation triggered when the soil moisture depletion<AD
A. Polvere, 2012
Soil Water Balance
Water Balance• Daily soil water balance – measure water in and out:𝐸𝑇𝐶,𝑖 = 𝐼𝑁,𝑖 + 𝑃𝑖 − 𝑅𝑂𝑖 − 𝐷𝑃𝑖 + 𝐶𝑅𝑖 ± (𝐷𝑖−1 − 𝐷𝑖)
– D (mm) soil water content assuming i is the current day and i−1 is the previous day
– P (mm) daily precipitation
– RO (mm) runoff
– IN (mm) net irrigation depth
– CR (mm) capillary rise
– ETC (mm) crop evapotranspiration
– DP (mm) is the deep percolation
𝐸𝑇𝐶,𝑖 = 𝐼𝑁,𝑖 ±(𝐷𝑖−1 − 𝐷𝑖)(Allen et al., 1998)
Actual Water Use (ETa)
• Actual water use only measured for the 2nd
and 3rd cuttings
• Used Neutron Probe:
– Releases neutrons at high speed
– Collide with H protons, return thermalized
– Measurements taken at 5 depths: • 20, 40, 60, 80 and 100 cm
http://www.rwma.com
Sample Neutron Probe Reading
0
20
40
60
80
100
0 5 10 15 20 25 30
De
pth
(cm
)
% Moisture
7/23/12
Full
75%
50%
25%
Estimated ETc
• Water use estimated for all cuttings as:
– ETc = Kc x ETo
• Used ETo from the weather station and crop coefficients (Kc) calculated from actual weather data.
WATERMARK Sensors• For irrigation scheduling purposes only
• Measure soil electric conductivity (EC), relate it to the matric potential of the soil (cb)
• 4 depths:o 15 cm
o 30 cm
o 60 cm
o 90 cm
Nutrient Qualityo DM – Dry Matter
o ADF – (Acid Detergent Fiber) cellulose + fiber + lignin
o NDF – (Neutral detergent fiber) total fiber or cell wall fraction
o CP – Crude protein
o TDN – Total Digestible Nutrients
o RFV – Relative Feed Value
http://www.foss.dk/
Measured with Near Infrared Reflectance Spectroscopy (NIRS)
EFFECTS OF LIMITING WATER ON WATER USE AND WATER USE EFFCIENCY OF ALFALFA
Weather2011 and 2012 weather compared to the long
term average (LTAvg)Max Temp (°C) Min Temp (°C) Precipitation (mm)
LTAvg 2011 2012 LTAvg 2011 2012 LTAvg 2011 2012
Jan 0.3 -0.5 4.7 -13.4 -12.2 -9.2 4.8 1.8 0.5
Feb 3.1 -2.3 3.5 -11.1 -14.8 -9.3 2.8 2.0 3.8
Mar 9.4 8.9 16.3 -5.8 -4.8 -1.4 7.1 6.4 10.7
Apr 14.6 11.9 17.9 -0.9 -1.8 1.2 12.7 26.3 4.8
May 19.5 15.1 20.2 4.9 4.2 4.5 37.1 78.0 20.1
Jun 24.8 24.5 29.4 9.0 8.5 11.3 33.3 6.1 8.1
Jul 29.7 32.5 32.9 11.9 13.5 14.4 22.1 1.3 4.6
Aug 29.3 31.1 30.5 10.5 11.9 11.7 11.9 9.9 0.5
Sep 22.7 25.9 26.1 5.1 6.7 7.6 17.0 12.7 2.5
Oct 15.0 16.9 14.1 -1.1 2.2 -0.5 15.5 35.8 5.1
Nov 6.7 5.6 8.3 -7.3 -7.4 -5.6 5.1 6.9 2.3
Dec 0.4 -0.4 0.7 -13.1 -12.0 -11.3 3.8 2.0 2.5
Average 14.6 14.2 17.1 -0.9 -0.4 1.1 Total 176 189 66
2012 Dry Matter Yield
0
1000
2000
3000
4000
5000
6000
7000
100% 75% 50% 25%
DM
(kg
ha-1
)
a) 1st Harvest
a‡
a
b
b
0
1000
2000
3000
4000
5000
6000
7000
100% 75% 50% 25%
b) 2nd Harvest
a
b
c
d
0
1000
2000
3000
4000
5000
6000
7000
100% 75% 50% 25%
DM
(kg
ha-1
)
Irrigation Treatment
c) 3rd Harvest
ab
c
d
0
1000
2000
3000
4000
5000
6000
7000
100% 75% 50% 25%
Irrigation Treatment
d) 4th Harvest
a a
b
b
DM= 21.48ETe - 284n = 45; R² = 0.58
0
2000
4000
6000
8000
0 100 200 300
DM
Yie
ld (
khh
a-1)
ETe (mm)
DM = 38.12xETa- 1212.7n = 45; R² = 0.82
0
2000
4000
6000
8000
0 100 200
DM
Yie
ld (
kg h
a-1)
ETa (mm)
DM = 17.32ETe + 609.33n = 46; R² = 0.83
0
2,000
4,000
6,000
8,000
0 100 200 300
DM
Yie
ld (
kg h
a-1
)
ETe (mm)
DM = 19.47ETe - 110.18n = 46;R² = 0.72
0
2000
4000
6000
8000
0 100 200
DM
Yie
ld (
kg h
a-1
)
ETa (mm)
‡Different letters within each harvest indicate significant difference (p<0.05) between irrigation treatments.
2012 Total Dry Matter Yield
0
4000
8000
12000
16000
20000
100% 75% 50% 25%
DM
(kg
ha-1
)
Irrigation Treatment
e) Total Harvest
b
c
d
a‡
DM = 22.32ETc - 404.15n = 46;R² = 0.83
0
5000
10000
15000
20000
25000
0 200 400 600 800
DM
Yie
ld (
kg h
a-1)
ETc (mm)
‡Different letters within each harvest indicate significant difference (p<0.05) between irrigation treatments.
Water Use of Alfalfa
Cut 2R2 = 0.94
Cut 3R2 = 0.96
0
1
2
3
4
5
0 1 2 3 4 5
Act
ual
WU
E (k
g m
-3)
Estimated WUE (kg m-3)
Water Use Efficiency
Cut 2R² = 0.99
Cut 3R² = 0.99
0
50
100
150
200
250
0 50 100 150 200 250
Act
ual
ET c
(mm
)
Estimated ETc (mm)
Water Use
Actual vs. Estimated ETc and WUE
100%1st
Harvest2nd
Harvest3rd
Harvest4th
Harvest Season
Date 6-June§ 12-July 21-Aug 11-Oct
WB 146 217
ASCE-PM 231 142
Total 231 146 217 143 737
75%1st
Harvest2nd
Harvest3rd
Harvest4th
Harvest Season
Date 6-June 12-July 21-Aug 11-Oct
WB 111 146
ASCE-PM 173 103
Total 173 111 146 103 533
50%1st
Harvest2nd
Harvest3rd
Harvest4th
Harvest Season
Date 6-June 12-July 21-Aug 11-Oct
WB 84 101
ASCE-PM 116 70
Total 116 84 101 70 371
25%1st
Harvest2nd
Harvest3rd
Harvest4th
Harvest Season
Date 6-June 12-July 21-Aug 11-Oct
WB 50 48
ASCE-PM 58 35
Total 58 50 48 35 191
Water Use (ETc)
• §First growth period assumed to begin on April 1st
2012 Water Use and
WUE
0
1
2
3
4
5
100% 75% 50% 25%
WU
E kg
m-3
Irrigation Treatment
1st Harvest
2nd Harvest
3rd Harvest
4th Harvest
ab
baa a b
a‡
‡Different letters within each harvest indicate significant difference (p<0.05) between irrigation treatments.
• Larger variation in WUE for the 2nd and 3rd cuttings, in the middle of the season.
• Fully irrigated treatment showed higher WUE early in the season.
0
50
100
150
200
250
100% 75% 50% 25%W
ate
r U
se (
mm
)
1st cutting
2nd cutting
3rd cutting
4th cutting
EFFECTS OF LIMITING WATER ON GROWTH AND FORAGE QUALITY OF ALFALFA
Dry Matter Production
0
1000
2000
3000
4000
5000
4/16 5/31 7/15 8/29 10/13
Yie
ld (
kg h
a-1
)
Shaw
0.25ET
0.50ET
0.75ET
1.00ET
0
1000
2000
3000
4000
5000
4/16 5/31 7/15 8/29 10/13
Yie
ld (
kg h
a-1
)
Mountaineer
010002000300040005000
4/16 5/31 7/15 8/29 10/13
Yie
ld (
kg h
a-1
)
Date
Lander
• Mountaineer showed better yield for fully irrigated.
• Shaw showed better yield in deficit treatments.
2012 Forage Quality
15%
17%
19%
21%
23%
25%
27%
29%
31%
1st Harvest 2nd Harvest 3rd Harvest 4th Harvest
% Crude Protein
100%
75%
50%
25%
10%
20%
30%
40%
1st Harvest 2nd Harvest 3rd Harvest 4th Harvest
% Acid Detergent Fiber
100%
75%
50%
25%
10%
20%
30%
40%
50%
1st Harvest 2nd Harvest 3rd Harvest 4th Harvest
% Neutral Detergent Fiber
100%
75%
50%
25%
89%
90%
91%
92%
93%
94%
95%
1st Harvest 2nd Harvest 3rd Harvest 4th Harvest
% Dry Matter
100%
75%
50%
25%
2012 Forage Quality
40%
50%
60%
70%
80%
90%
1st Harvest 2nd Harvest 3rd Harvest 4th Harvest
% Total Digestible Nutrients
100%
75%
50%
25%
100
130
160
190
220
250
1st Harvest 2nd Harvest 3rd Harvest 4th Harvest
Realtive Feed Value
100%
75%
50%
25%
Quality Grade ‡RFV ADF % NDF % §TDN-100% TDN-90% Crude Protein %
Supreme >185 <27 <34 >62 >55.9 >22
Premium 170-185 27-29 34-36 60.5-62 54.5-55.9 20-22
Good 150-170 29-32 36-40 58-60 52.5-54.5 18-20
Fair 130-150 32-35 40-44 56-58 50.5-52.5 16-18
Low <130 >35 >44 <56 <50.5 <16
• USDA hay quality guidelines†:
†(Oregon Hay and Forage Association).
IRRIGATION SCHEDULING: POTENTIAL ECONOMIC IMPLICATIONS FOR THE PRODUCER
2012 WATERMARKs
0
10
20
30
40
0
50
100
150
200
250
300
4/2 4/17 5/2 5/17 6/1 6/16 7/1 7/16 7/31
Irri
gati
on
am
ou
nt
(mm
)
Mat
irc
Po
ten
tial
(cb
) a) 100%
0
10
20
30
40
0
50
100
150
200
250
300
4/2 4/17 5/2 5/17 6/1 6/16 7/1 7/16 7/31
Irri
gati
on
am
ou
nt
(mm
)
Mat
irc
Po
ten
tial
(cb
) b) 75%
0
10
20
30
40
0
50
100
150
200
250
300
4/2 4/17 5/2 5/17 6/1 6/16 7/1 7/16 7/31
Irri
gati
on
Am
ou
nt
(mm
)
Mat
irc
Po
ten
tial
(cb
) c) 50%
0
10
20
30
40
0
50
100
150
200
250
300
4/2 4/17 5/2 5/17 6/1 6/16 7/1 7/16 7/31 Irri
gati
on
Am
ou
nt
(mm
)
Mat
irc
Po
ten
tial
(cb
)
Date
d) 25%
15 30 60 90 Irrigation Depth (mm)
• Soil moisture present at the beginning of the season.
• Reaction to irrigation.• Small irrigations early
in season.• 15 cm and 30 cm seem
to be best.
Economic Analysis
Irrigation applied
(mm) Yield (t ha-1)
Diesel @
$0.92 liter-1
Diesel @
$1.06 liter-1
Electricity @
$0.025 MJ-1
Baseline 762 15.2 $2,888.69 $2,874.91 $2,950.12
Recommendation 559 15.2 $2,914.41 $2,904.30 $2,959.45
Deficit Irrigation 356 11.1 $1,936.24 $1,929.81 $1,964.90
Irrigation applied
(mm) Yield (t ha-1) $157§ t-1 $242† t-1 $274‡ t-1
Baseline 762 15.2 $1,584.76 $2,888.69 $3,378.50
Recommendation 559 15.2 $1,610.48 $2,914.41 $3,404.22
Deficit Irrigation 356 11.1 $987.05 $1,936.24 $2,292.79
• Sensitivity to energy prices: Net revenue, not including overhead ($ ha-1):
• Sensitivity to hay prices: Net revenue, not including overhead ($ ha-1):
Describe the field
Potential $ Savings
Energy Price
Diesel @ $0.92 liter-1 Diesel @ $1.06 liter-1 Electricity @ $0.025 MJ-1
Recommendation (559 mm
applied and yields of 15.2 t ha-1) $25.72 $29.39 $9.34
Deficit Irrigation (356 mm
applied and yields of 11.2 t ha-1) -$952.45 -$945.11 -$985.21
Hay Price ($ t-1)
$156.53 t-1 $242.07 t-1 $274.20 t-1
Recommendation (559 mm
applied and yields of 15.2 t ha-1) $25.72 $25.72 $25.72
Deficit Irrigation 356 mm
applied and yields of 11.2 t ha-1) -$597.71 -$952.45 -$1,085.71
• Savings per ha relative to baseline (762 mm applied and yield of 15.2 t ha-1)†:
• Savings per ha relative to baseline (762 mm applied and yield of 15.2 t ha-1)‡:
• Potential savings over the whole field: $460 to $1,500 per year.
†Hay price fixed at $242.07 t-1
‡Energy price fixed at $1.06 liter-1
Conclusions
1. No significant differences found in yield, forage quality and WUE among varieties.
2. Significant difference between irrigation treatments for yield and WUE.
3. WUE and quality more affected by the time of the year than by the irrigation amount.
4. Similar, or better, alfalfa yields can be produced with less water, with proper irrigation scheduling.
5. Economic analysis showed large potential energy savings, ranging from $9 to almost $30 ha-1.
Literature Cited• Allen, R.G., L.S. Pereira, D. Raes, and M. Smith. 1998. Crop evapotranspiration: Guidelines for computing crop water requirements. FAO Irrigation and drainage paper
56. Irrigation and Drainage 300(56):1–15.
• California Alfalfa and Forage Association. 2004. Commodity Fact Sheet Alfalfa. California Foundation for Agriculture in the Classroom, Sacramento, CA.
• Ditterline, R.L., R.L. Dunn, S.D. Cash, D.M. Wichman, L.E. Welty, J.L. Bergman, J.L.A. Eckhoff, M.E. Majerus, J.G. Scheetz, L.K. Holzworth, K.R. Blunt, L.S. Strang, and J.
• North American Alfalfa Improvement Conference. 1999. Mountaineer. Description of Alfalfa Cultivars and Germplasms. Available at http://www.naaic.org/varietyaps/mountaineer.htm (verified 4 November 2012).
• Oregon Hay and Forage Association. USDA quality guidelines for alfalfa hay . Hay Quality Designations. Available at http://www.oregonhaygrowers.com/qualitytesting.html (verified 8 May 2013).
• Vavrovsky. 2001. Registration of `Shaw’ Alfalfa. Crop Science 41(1): 264–265Available at https://www.crops.org/publications/cs/articles/41/1/264 (verified 24 January 2012).
• Russelle, M. 2001. After an 8,000-year journey, the“ Queen of Forages” stands poised to enjoy renewed popularity. American Scientist 89:252.
• USDA NASS. 2012. USDA NASS Quickstats. Available at http://quickstats.nass.usda.gov/ (verified 17 March 2012).
• Walter, I.A., R.G. Allen, R. Elliott, M.E. Jensen, D. Itenfisu, B. Mecham, T.A. Howell, R. Snyder, P. Brown, S. Eching, T. Spofford, M. Hattendorf, R.H. Cuenca, J.L. Wright, and D. Martin. 2000. ASCE’S Standardized Reference Evapotranspiration Equation. p. 209–215. In National Irrigation Symposium. American Society of Agricultural Engineers, Phoenix, AZ, USA.
THANK YOU!
o Mike Killen and his crewo UW Agricultural
Experiment Stationo Advisor: Axel Garcia y
Garciao Co-advisors: Anowar Islam
& Kristi Hanseno Joan Tromble and Andrea
Piersono My family
QUESTIONS?