simulated effects of a cover crop on the yield

Effect of Cover Crop Termination Timing on the Yield of a Following Crop in Rotation

USDA‐NRCS

Joel K PooreConservation Agronomist, Wind Erosion Specialist

[email protected]

SWCS Conference, July, 2014, Lombard IL

Helping People Help the Land 1

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


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


WEPS 1.3.9 NRCS release download available for TSP use www.nrcs.usda.gov/Topics/Technical Resources/Tools & Applications/Wind Erosion (WEPS)


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 )

Helping People Help the Land

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


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:


Quantitative Support for NRCS Cover Crop Termination GuidelinesMarch 2013

CHECK, SW–Corn

CCTT 35 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


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


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%


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


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


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%


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


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


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


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


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


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


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


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


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


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


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

[email protected]

SWCS Conference, July, 2014, Lombard IL


simulated effects of a cover crop on the yield

Environment