Department of Soil Health Testing does not Differentiate · PDF file ·...
Transcript of Department of Soil Health Testing does not Differentiate · PDF file ·...
Conclusions
• CASH soil health indicators lack sensitivity to quantify differences in long-term agronomic systems in southern soils.
• Soil health management recommendations for agronomic systems need to be adjusted to account for differences inintrinsic soil properties and agroecological regions.
• There is no relationship between crop yields and current soil health indicators.
Background
Soil Health Testing does not Differentiate Long-term AgronomicSystems in North CarolinaWayne Roper, Deanna Osmond, Joshua Heitman, Michael Wagger, Chris Reberg-Horton
1) Determine if soil health indicators can distinguish between cropping and tillage systems in North Carolina.
2) Compare soil test results and their implications for soil management recommendations.
3) Assess relationships between soil health testing and crop yields.
Methods and Materials
The study consisted of long-term research trials that represented mountain,piedmont, and coastal plain soil types of North Carolina
Mountain Piedmont Coastal Plain
City Mills River Reidsville Goldsboro
Established 1994 1984 1999
Plot Size and design
12.2 x 24.4 m (40 x 80 ft) 20 plots, CRD
5.8 x 15.2 m (19 x 50 ft)36 plots, RCBD
Various sizes12 plots, RCBD
Crops Vegetables (1994-2006)Corn (2006-2014)
Corn and soybean annual rotation Various vegetablesCorn and soybean annual rotation
Treatments(management)
NTCNTOCTCCTOCTX
- No-till chemical- No-till organic- Conventional chemical- Conventional organic- Conventional fallow
NTCIRSDSCPSCPFCPDSCPDFMPDSMPDF
- No-till chemical- In-row Subsoil - Spring- Disk - Spring- Chisel - Spring- Chisel - Fall- Chisel/Disk - Spring- Chisel/Disk - Fall- Moldboard/Disk - Spring- Moldboard/Disk – Fall
NTCRTOCTOCTC
- No-till chemical- Reduced-till organic- Conventional organic- Conventional chemical
Cover Crop Annual wheat and crimson clover in all plots
None Sudangrass, clover, vetch (org)Rye (conventional)
Soil Type Delanco silt loam Wedowee sandy loam Wickham sandy loam; Tarboro
Management History
Index Score
NCDA&CS Soil Testing
Results
CASH Soil Indicator Index Scores
Department of Crop and SoilSciences
Objectives
• More research is needed to determine the significance of soil health indicators in quantifying the effects of agronomic practices on soil properties and productivity.
• A current focus in soil research is ‘soil health’, which is the ability of soilto function as a sustainable vital ecosystem.
• Several physical, chemical, and biological soil properties have beenreferenced as indicators of soil health.
• The utility of these indicators for soil management recommendations in different agronomic systems is not yet clear.
Contact:
Wayne [email protected] Williams HallNC State University
• All tillage and cropping systems, except Mountain NTO were rated low by the CASHregardless of the presence of cover crops or other conservation tillage practices.
• Essential plant nutrients were in sufficient quantity for every treatment.
• Biological soil indicators were rated low in each system and were the reason whymanagement systems were rated low overall.
Research Trials
MountainMills River
PiedmontReidsville
CoastalGoldsboro
Soil Sampling and Testing
Soil subsamples were collectedat random points within a plotand combined to produce arepresentative plot sample.
Approximately 470 cm3 (2 cups)of soil from the top 0-15 cmwas collected for soil testing byNCDA&CS.
Approximately 1400 cm3 (6cups) of soil from the top 0-15cm was collected for the CASH.
North Carolina Department of Agriculture & Consumer Services (NCDA&CS)
NCDA&CS soil testing extractsessential plant nutrients from soiland uses an index scale conversionto recommend fertility applicationsfor specific crops.
Cornell’s CASH evaluates chemical,physical, and biological soilproperties and makes generalmanagement recommendations ona 0-100 index scale.
Comprehensive Assessment of Soil Health (CASH)
Very High (85-100)
High (70-85)
Medium (55-70)
Low (40-55)
Very Low (0-40)
Score Descriptors(2015 rating scale)
NTC IRS DS CPF CPS CPDF CPDS MPDF MPDS NTC RTO CTC CTO0
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90
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NTC NTO CTC CTO CTX
NTC IRS DS CPF CPS CPDF CPDS MPDF MPDS NTC RTO CTC CTO
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90
100
NTC NTO CTC CTO CTX
Comprehensive Assessment of Soil Health (CASH)
• Available Water Capacity• Surface Hardness• Subsurface Hardness• Aggregate Stability• Organic Matter• Soil Protein• Soil Respiration• Active Carbon• pH• Phosphorus• Potassium• Minor Elements
Ph
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alB
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CASH Soil Indicators
CASH Overall Soil Health Score
Mountain Piedmont Coastal Plain
–––––––––––––––––––––––––––––––––––––––––––––––– Treatment ––––––––––––––––––––––––––––––––––––––––––––––––
–––––––––––––––––––––––––––––––––––––––––––––––– Treatment ––––––––––––––––––––––––––––––––––––––––––––––––
Pie
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• There was no statistical difference in humic matter (representative of organic matter) between agronomic systems with conservation tillage and those with intense tillage.
• Soil test levels of major plant nutrients were adequate (data not shown).
Crop Yields (* indicates years with statistically different yields between treatments in the trial)
Humic Matter (%)
Index Score
Coastal PlainPiedmont
Note: Lime and fertilizer was applied to all plots according to NCDA&CS soil test recommendations
Mountain
Acknowledgements:
Mountain Piedmont Coastal Plain
PiedmontMoldboard plowed plot (left) adjacent to a no-till plot (right) Funding from:
• Conventional no-till systems yielded more corn than moldboard plowing, but not more than other tillage systems.• No-till organic production in the mountains had better soil health scores than conventional production, but yielded less
corn because of weed competition (instead of soil constraints).
0.00 0.20 0.40 0.60 0.80
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MPDS
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Adam Howard, Wesley Childres, Tomas Moreno, Melissa Belland all research station personnel
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