simulated effects of a cover crop on the yield
DESCRIPTION
69th SWCS International Annual Conference “Making Waves in Conservation: Our Life on Land and Its Impact on Water” July 27-30, 2014 Lombard, ILTRANSCRIPT
Effect of Cover Crop Termination Timing on the Yield of a Following Crop in Rotation
USDA‐NRCS
Joel K PooreConservation Agronomist, Wind Erosion Specialist
SWCS Conference, July, 2014, Lombard IL
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Initial Question
What is the Optimum Cover Crop Termination Timing CCTT to Reduce the Risk of Yield Loss to a Following Crop in rotation ?
Potential Benefits: Improved Water Quality and Quantity, Soil Quality, Soil ErosionImprove adoption of cover crops in rotations
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Improve understanding of CCTT EFFECT on Following Crop Yields
Site specific Cost / Benefit Analysis
Realize potential resource benefits
Consistent, science based technical guidance for CCTT
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Process Based Models
Use current Wind Erosion Prediction System WEPS NRCS release 1.3.9
Science Model: WEPS Sub‐models interact during a simulation for a crop system
1. Growth2. Weather
3. Soil4. Erosion
5. Decomposition6. Hydrology
7. Management
Simulation Inputs: WEPS Interface and Management editorSimulation Data: Current NRCS CROPS, OPERATIONS and other Databases Simulation Results: Run, Crop, Management, STIR and Detailed reports
Innovative Use of an Existing science based Technology developed by USDA‐ARSCrop System and WEPS Inputs = Site + Crop Rotation Management
Temporal processes during crop system
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WEPS 1.3.9 NRCS release download available for TSP use www.nrcs.usda.gov/Topics/Technical Resources/Tools & Applications/Wind Erosion (WEPS)
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1. Benchmark crop system: Winter Wheat ‐ Fallow rotation
2. Alternative crop system: Winter Wheat ‐ Cover Crop ‐ Fallow
Winter Wheat planting: Sept 15 Winter Wheat harvest: July 10
Winter pea cover crop planting: March 15 Cover Crop Termination: June 15CCTT ( 90 DBP Winter Wheat )
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Field Based Example Inputs: WEPS Simulation: Evaluation of 2 crop systems
Location/Climate: Logan Co KansasSoil: Sandy LoamManagement: No‐Till System
All other WEPS inputs were constant 2 simulation runs
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Methods
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Methods: Example WW‐Fallow, Logan Co KS, Sandy Loam, No Till, CCTT 90 DBP
50 year WEPS simulation Run results Winter Wheat Yield Data Collection
Sandy Loam Soil WW‐Fallow WW‐CC‐Fallow CCTT 90 DBPSimulation Weather Bu/Ac Bu/Ac % Target YieldMean (average precip.) 38 38 99%Minimum (dry year) 23 21 91%Maximum (wet year) 59 58 98%‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐CCTT – Cover Crop Termination TimingCover Crop – Spring planted Austrian Winter PeaTarget Crop – Winter WheatNon‐calibrated RUNS
What is the risk tolerance of the user?
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Methods: Example WW‐Fallow, Logan Co KS, Sandy Loam and Silt Loam, No Till, CCTT 90 DBP
50 year WEPS simulation Run results Winter Wheat Yield Data Collection
Sandy Loam Soil WW‐Fallow WW‐CC‐Fallow CCTT 90 DBPSimulation Weather Bu/Ac Bu/Ac % Target YieldMean (average precip.) 38 38 99%Minimum (dry year) 23 21 91%Maximum (wet year) 59 58 98%‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Silt Loam Soil WW‐Fallow WW‐CC‐Fallow CCTT 90 DBPSimulation Weather Bu/Ac Bu/Ac % Target YieldMean (average precip.) 54 51 94%Minimum (dry year) 38 28 74%Maximum (wet year) 80 81 101%
CCTT – Cover Crop Termination TimingCover Crop – Spring planted Austrian Winter PeaTarget Crop – Winter WheatNon‐calibrated RUNS
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% Target Soil profile Hydrology DBP 90: Crop Period: WW Harvest – WW PlantingRunoff mean 89%Evaporation mean 91%Drainage mean 74%Ending SWC mean 98%
Transpiration during Benchmark Fallow crop period: 0 mmCover crop Winter Pea Transpiration 136 mmCover crop Biomass @ termination 990 Dry Matter lbs/acCanopy cover @ termination 78%
Additional results from Example WEPS simulation
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Methods: Example WW‐Fallow, Logan Co KS, Sandy Loam, No Till, CCTT 90 DBP
WEPS Simulations: Study Design
BenchmarkCheck Treatments (40): 1 crop rotation, 2 Managements, 2 Soils, 10 locations
AlternativesCCTT Treatments (120): 3 crop rotations, 2 Managements, 2 Soils, 10 locations
3 CCTT DBP Treatments
Methods:
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Quantitative Support for NRCS Cover Crop Termination GuidelinesMarch 2013
CHECK, SW–Corn
CCTT 35 DBP, SW‐fall seeded triticale CC– Corn Rotation
CCTT 20 DBP, SW‐fall seeded triticale CC– Corn Rotation
CCTT 05 DBP, SW‐fall seeded triticale CC– Corn Rotation
Adams Co, WI Hitchcock Co, NE
Baylor Co, TX Logan Co, IL
Boone Co, IA McIntosh Co, ND
Dyer Co, TN Sampson Co, NC
Ford Co, KS York Co, PA
Methods: Site Factor: Location Climate
Methods: Management Factor: Crop Rotation Treatments
Initial Study Design: Crop System = Site Factors + Management Factors
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LFS: Valent loamy fine Sand
L: Clarion Loam
Methods: Management Factor: Residue and Tillage systems
Methods: Site Factor: Soil Profile variable
TILL: Tillage system
NT: No‐Till system SW and Corn residue removed after harvest (40% of flat residue)
Initial Study Design: Crop System = Site Factors + Management Factors
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Data Collection: Example for Boone Co Iowa: Full Tillage: Clarion Loam: Check and 3 CCTT treatments: 4 simulations
SW‐Corn and SW‐Triticale CC‐Corn: Normalized Data as % of Target Crop Yield
Boone Co IA
TillageSW
Ave YieldCorn
Ave YieldCorn
Min YieldCorn
Max Yield
Clarion loam Bu/ac Bu/ac Bu/ac Bu/ac
w/o CC CHECK 100.0% 100.0% 100.0% 100.0%
W CCTT 35 DBP 100.0% 101.5% 100.1% 100.9%
W CCTT 20 DBP 100.0% 101.8% 100.4% 101.0%
W CCTT 5 DBP 100.0% 97.5% 100.7% 101.7%
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Data Collection: Hydrology: Example for Boone Co Iowa: Full Tillage: Clarion Loam: Check and CCTT 35 DBP treatments
RotationSWC iniinch
SWC endinch
Precipitationinch
Runoffinch
Evaporationinch
Transpirationinch
Drainageinch
Check 27.0 28.7 21.8 1.8 10.8 0.0 7.6
CCTT 35 DBP 27.0 28.0 21.8 1.7 6.6 6.6 4.3
% of CHECK 100.2% 97.6% 100% 94.1% 61.0% .‐‐. 57.2%
0
10
20
30
40
SWC ini SWC end rain runoff evap trans drain
Waterinches
Soil Profile Water Components
SW Harvest to Corn Planting 9 month crop period: Tillage system: Loam soil
SW‐Corn SW‐CC‐Corn
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InterpretationCCTT EFFECT: % Target Yield: CHECK and CCTT 35 DBP example: 40 simulations
CCTT DBP 35 Average
Location No‐Tillage Tillage No‐Tillage Tillage Soil & TillageAdams Co, WI 104.1% 100.9% 105.6% 101.6% 103.1%
Baylor Co, TX 92.5% 74.9% 115.4% 103.0% 96.5%Boone Co IA 104.8% 101.5% 107.1% 102.8% 104.1%
Dyer Co, TN 108.0% 104.2% 112.6% 108.7% 108.4%
Ford Co KS 90.4% 77.3% 108.5% 98.5% 93.7%
Hitchcock Co NE 92.3% 79.6% 107.2% 98.2% 94.3%
Logan Co IL 106.8% 102.1% 110.3% 105.9% 106.3%McIntosh Co, ND 95.1% 87.9% 105.3% 101.9% 97.5%Sampson Co, NC 105.4% 102.6% 111.3% 107.9% 106.8%
York Co, PA 106.5% 102.3% 109.3% 105.2% 105.8%
Average Locations 100.6% 93.3% 109.3% 103.4% 101.6%
% of Target Yield response for Average Growing Condition CCTT DBP 35
Clarion Loam Valent loamy fine Sand
Soil and Tillage management have significant EFFECT on % of Target Yield
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Interpretation:Significant % Target Crop Yield, Standard Error analysis with n= 50 simulation years
LocationStandard Error
Bu/ac2 X Standard Error
Bu/acStandard Error % TRG YLD
2 X Standard Error % TRG YLD
Adams Co, WI 2.2 4.4 2.3% 4.6%York Co, PA 2.6 5.2 2.5% 5.0%Sampson Co, NC 4.1 8.1 2.7% 5.5%Boone Co IA 3.2 6.4 2.9% 5.8%Logan Co IL 3.0 6.0 3.2% 6.5%Dyer Co, TN 4.2 8.4 3.8% 7.6%Baylor Co, TX 2.5 5.1 4.2% 8.4%McIntosh Co, ND 2.8 5.5 4.3% 8.5%Hitchcock Co NE 2.5 5.1 4.3% 8.6%Ford Co KS 2.8 5.5 4.4% 8.8%
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Location PE Index Location PE Index
Adams Co, WI 75 Hitchcock Co NE 37Baylor Co, TX 44 Logan Co IL 86Boone Co, IA 76 McIntosh Co, ND 40Dyer Co, TN 104 Sampson Co, NC 80Ford Co KS 37 York Co, PA 101
Site Factor Climate Variable: Precipitation Effectiveness Index (Thornthwaite 1931)Index based on Monthly precipitation and Temperature data
Identify Trend in CCTT EFFECT on Yield relationship to location To Identify a Trend, A Predictor variable for Location Climate is needed
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WEPS Simulations: CCTT DBP treatments: PEI and % Target Crop Yield response Study Location PE Index CCTT 35 DBP CCTT 20 DBP CCTT 5 DBP
Ford Co KS 37 92 89 86
Hitchcock Co NE 37 93 90 87
McIntosh Co, ND 40 97 96 88
Baylor Co, TX 44 93 89 84
Adams Co, WI 75 103 104 103
Boone Co IA 76 104 105 102
Sampson Co, NC 80 106 103 98
Logan Co IL 86 106 103 95
York Co, PA 101 106 105 102
Dyer Co, TN 104 108 106 103
y = 0.2314x + 84.864R² = 0.9066
90
100
110
20 40 60 80 100 120
% TRG
YLD
Location: Precipitation Effectiveness Index
CCTT 35 DBP Average Precipitation, Soil & Management
% Target Yield Response to Location
Interpretation: Basic Trend Line Approach: Linear: CCTT 35 DBP ExampleAverage Soils and Tillage treatments
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CCTT EFFECT EQ 1% Target Crop Yield = (((‐0.001*CCTT DBP) + 0.271) *PE Index) + ((0.2617*CCTT DBP) + 75.8)
% TRG YLD: PE Index linear equations for each of the CCTT DBP treatments35 DBP y = 0.2314x + 84.864 R² = 0.906620 DBP y = 0.2614x + 81.227 R² = 0.855805 DBP y = 0.2610x + 77.012 R² = 0.7791
CCTT DBP Slope Y Intercept35 0.2314 84.86420 0.2614 81.2275 0.2610 77.012
y = ‐0.001x + 0.271R² = 0.7399
0.2250.23
0.2350.24
0.2450.25
0.2550.26
0.2650.27
0 10 20 30 40
Slop
e coef
CCTT DBP
Slope
y = 0.2617x + 75.8R² = 0.9982
76
78
80
82
84
86
0 10 20 30 40% TRG
YLD
CCTT DBP
Y intercept
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Interpretation: CCTT EFFECT EQ 1: Initial Linear approach
Estimated Cover Crop Termination Timing EFFECT on Target Yield of a Following Crop
PE INDEX Input value ==> 24
CCTT DBP Input value ==> 90
% "Target Crop Yield" Average Precipitation, Soil and Management Treatments
103.7
Soil Loam Loamy fine sand
Management No till Tillage No till Tillage
% "Target Crop Yield" Soil and Management Treatments
96.1 88.7 116.2 116.2
Cover crop guideline based on location Climate and CCTT only ‐ ‐ very, very general
Field Specific Soil and Tillage management variables are important to consider
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CCTT EFFECT EQ 2: Trend Line analysis of Log Normal distribution of % Target Crop Yield
y = 14.726ln(x) + 39.576R² = 0.9374
90
95
100
105
110
0 20 40 60 80 100 120
% TRG
YLD
T
Location: Precipitation Effectiveness Index PEI
CCTT 35 DBPAverage Precipitation, Soil & Management
% Target Yield Response to PE Index
% TRG YLD: PE index log normal equations for each of the CCTT DBP treatments35 DBP y = 14.726ln(x) + 39.576 R² = 0.9420 DBP y = 16.710ln(x) + 29.757 R² = 0.8905 DBP y = 16.697ln(x) + 25.571 R² = 0.81
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Y Intercept and Slope coefficient estimated by CCTT DBP
Cover Crop Termination Timing CCTT Effect on Target Crop Yield
CCTT days prior to planting Target Crop INPUT => 90
PEI county value INPUT => 24
Average Annual Growing conditions (Precipitation and Temperature)
Average Soil (Loamy Fine Sand and Loam)
Average Tillage system (No‐Till residue removed and Full Tillage system)
Linear Trend Line Approach 103.7 % of Target Yield
% Target Crop Yield = (((‐0.001*CCTT DBP) + 0.271) *PE Index) + ((0.2617*CCTT DBP) + 75.8)
log Normal Trend Line Approach 100.7 % of Target Yield
% Target Crop Yield = (((‐0.0657*CCTT DBP)+17.358)*LN(PE Index)+((0.4668*CCTT DBP)+22.298))
CCTT EFFECT EQ 1 and 2: Compare Log Normal and Linear Trend line approach
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Cover Crop Termination Timing CCTT Effect on Non‐Irrigated Following Crop Yield
State Click and Select State => Colorado
County Click and Select County => Otero CO
CCTT DBP Target Crop Manual Input => 90
County Precipitation Effectiveness Index PE Index 23
Average Soil Average Management
Cover Crop Termination Timing EFFECT: % TARGET CROP YIELD Estimates
CCTT EFFECT EQ 1 CCTT EFFECT EQ 2 CCTT EFFECT EQ 3 CCTT EFFECT EQ 4 CCTT EFFECT EQ 5
103.5 100.2 82.6 91.4 90.1
D8_Table 5 CCTT tool eq1_5.XLSX Initial Study Data: 180 WEPS simulations JKP, 5/20/2014
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CCTT EQ 1: Linear equation, average Year, soils and tillage management CCTT EQ 2: Log Normal equation: average Year, soils and tillage management CCTT EQ 3: Log Normal equation: Minimum Yield, dry year: average Soils and TillageCCTT EQ 4: Log Normal equation: Adjust EQ 3 dry year results for adapted plant materialsCCTT EQ 5: Log Normal equation: Adjust EQ 4 for improved Soil Factor average
Cover Crop Termination Timing CCTT Effect on Non‐Irrigated Following Crop Yield
State Click and Select State => Illinois
County Click and Select County => Johnson IL
CCTT DBP Target Crop Manual Input => 10
County Precipitation Effectiveness Index PE Index 82
Average Soil Average Management
Cover Crop Termination Timing EFFECT: % TARGET CROP YIELD estimates
CCTT EFFECT EQ 1 CCTT EFFECT EQ 2 CCTT EFFECT EQ 3 CCTT EFFECT EQ 4 CCTT EFFECT EQ 5
99.8 100.6 99.0 99.8 98.4
Valid: Continental Summer Rainfall Climate pattern locationsD8_Table 5 CCTT tool eq1_5.XLSX 5/20/2014
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Summary: CCTT EFFECT on Following Crop Yield
Process based models useful tools for Crop System studies and decision makingRecommend: Single field based comparison of a Benchmark and Alternative crop system using WEPS
General CCTT guidelines can be developedFine tune decisions with field specific simulations and local research
Trend Line Equations, 2 predictor variables: Climate (PE Index) and CCTT DBPAverage Soil and Residue Tillage Management – not field specific
CCTT EQ 1: Linear equation, average Year, soils and tillage management CCTT EQ 2: Log Normal equation: average Year, soils and tillage management CCTT EQ 3: Log Normal equation: Minimum, dry year: average Soils and tillage managementCCTT EQ 4: Log Normal equation: Adjusted EQ 3 dry year results for adapted plant materialsCCTT EQ 5: Log Normal equation: Adjusted EQ 4 for improved Soil Factor average
Expanded Study: # Soils‐7, Management ‐ Add NT without corn and SW residue removedRecommend: Multi‐Variable regression equation, 3 predictor variables, Climate, Soil and Tillage
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Summary
Dynamic soil properties such as Infiltration (ability of soil to recharge after CCTT): KeyInfiltration improves as Soil Health Improves, reducing Risk of negative CCTT EFFECT on Crop Yields
User defined Target Crop, Target Yield, Significant difference or risk level ****Normalize simulated Yield results for benchmark and alternative as % of Target Yield
Cover Crop canopy cover vs Biomass: reduced runoff, erosion, leaching and evaporationCC does transpire stored soil profile water, but has significant EFFECT on water losses
Dry summer climates (West and NW) were not evaluated: Use WEPS for Field specific evaluationClimate patterns for locations are very stable, annual intensity is variable (dry vs wet year)
Simulated crops: Full stand emergence: Adjust Planting to seedbed condition Simulated cover crops: Termination date means DEAD
Multiple Simulation Climate and Soil Yield comparisons: Use non‐calibrated results and constant DB parameters: Fixed Crop growth and Yield processes response to Climate, Soil and management inputs Control Yield determining Variables, example NM and PM and varieties etc
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Effect of Cover Crop Termination Timing on the Yield of a Following Crop in Rotation
THANK YOU
USDA‐NRCS
Joel K PooreConservation Agronomist, Wind Erosion Specialist
SWCS Conference, July, 2014, Lombard IL
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