simple field tests to assess soil quality in precision agriculture
DESCRIPTION
Title. Simple Field Tests to Assess Soil Quality in Precision Agriculture. Apurba Sutradhar BAE/Soil 4213 April 28, 2010 [email protected]. Soil Quality. The capacity of specific kind of soil to function. To evaluate the soil’s ability to perform basic function - PowerPoint PPT PresentationTRANSCRIPT
Title
Simple Field Tests to Assess Soil Quality in Precision Agriculture
Apurba SutradharBAE/Soil 4213April 28, 2010
Soil Quality
The capacity of specific kind of soil to function.
To evaluate the soil’s ability to perform basic functionMaintaining productivityFiltering and buffering against pollutantsStoring and cycling nutrients.
Source: USDA Soil Quality Test Kit Guide
Soil Quality Varies
Source: USDA Soil Quality Test Kit Guide
Differences in agricultural practices Till Vs No till Differences in crop growth areas Fast growth Vs Slow growth Differences in slope Plain land Vs Slope land Differences in wheel and non wheel areas Wheel Vs Non wheel Differences in wet and dry areas Wet Vs Dry areas
Soil Quality Varies
Source: USDA Soil Quality Test Kit Guide
Also Field Variability can be determined by
Differences in soil type Eroded and non-eroded areas Row and inter -row areas
Assessing Soil Quality
Source: USDA Soil Quality Test Kit Guide
Two fundamental ways-
Take measurements periodically over time to monitor
changes or trends in soil quality.
Compare measured values to a standard or referenced soil condition.
Soil Quality Testing Kit
Source: USDA Soil Quality Test Kit Guide
Developed by John Doran and associates, Agricultural Research Service, Lincoln, NE.
Soil Quality Testing Kit
Source: USDA Soil Quality Test Kit Guide
Types
Chemical
pH
Electrical Conductivity
Nitrate level
Water quality
Physical
Bulk Density
Water content
Infiltration Rate
Aggregate Stability
Biological
Soil Respiration
Earthworms
Soil Quality Testing Kit
Source: USDA Soil Quality Test Kit Guide
Advantages:
On farm test Provide immediate results Can be monitored changes in soil quality over time Can be diagnosed soil health problems due to land use and management. Simple- can be conducted by landowner and extension worker
Soil Quality Testing Kit
Source: USDA Soil Quality Test Kit Guide
An example- Soil Respiration TestEstimated time required : 40 minutes
Soil Quality Testing Kit
Source: USDA Soil Quality Test Kit Guide
An example- Soil Respiration Test
CALCULATIONS:Soil Respiration (lb CO2-C/acre/day) = PF x TF x (%CO2 - 0.035) x 22.91 x HPF = pressure factor = 1TF = temperature factor = (soil temperature in Celsius + 273) ÷ 273H = inside height of ring = 5.08 cm (2 inches)
Planning-implementation-monitoring
Courtesy: Dr. Kefyalew Desta
Set Goal Standard Value Scoring
Data
Intervention
Applying Scoring
Monitoring and Maintenance
Data Collection and Scoring Steps
Courtesy: Dr. Kefyalew Desta
Data collection
Apply scoring system
Sum individual indicator values
Sum component values
General score and intervention
Individual indicator intervention
Scoring
Standard values
Standard/Reference Values
Courtesy: Dr. Kefyalew Desta
3.5-5 (>3.5)% SOM, %
>80 % Aggregate, %
<1.1, <1.4, <1.6 : clayey, silty, sandy BD,g/cm3
>40 Depth, in
0.4-2.0, 0.08-1.0, 0.01-0.1 : sand,loam,clay Infiltration rate, in/hr
2.4 - 3.5 Water holding, in/24 in soil
5.8-7.3 pH
N-100% of yield goal P&K- 100% sufficient Fertility
>50/50-100 CEC, meq/100g
<0.98 EC , dS/m
32-64 Soil respiration, lbs CO2-C/a/d
345-700 Soil microbial biomass mg , C/kg soil
> 15 Earth worm, #
Scoring
Courtesy: Dr. Kefyalew Desta
Applying the Scoring System
Courtesy: Dr. Kefyalew Desta
Indicator Value and (corresponding score)Best Good Poor
OM, % 3.5-5 (25) 2.5-3.5 (20) <2 (15)Physical properties
Water stable aggregation, %
>80 (6) 60-80 (4) 50-60 (2)
Bulk density, g/cm3 <1.1, <1.4, <1.6 (6) 1.1<BD<1.3,1.4<BD<1.6, 1.6<BD<1.7 (3)
>1.4, >1.6, >1.7 (1)
Depth, inch >40 (4) 20-40 (3) <20 (2)Infiltration rate, in/hr 0.4-2.0, 0.08-1.0,
0.01-0.1 (4)± 0.2 of best value (3) ± 0.4 of best value (2)
Water holding capacity, cm/60 cm soil
6-9 (5) 4-6, 9-10 (3) <4, >10 (1)
Applying the Scoring System
Courtesy: Dr. Kefyalew Desta
Chemical propertiespH (6) 5.8-7.3 (6) 5.0-5.7, 7.3-8.0
(4) <5, > 8 (2)
Fertility ( N, P and K),
N-100% of yield goal P&K- 100% sufficient (5)
N-80% of yield goal P&K- 80% sufficient (3)
N-< 80% of yield goal P&K- < 80% sufficient (1)
CEC, meq/100g soil
50-100 (5) 16-50 (3) <16 (1)
EC (dS/m @ 77 F) <0.98 (4) 0.98 - 1.71 (3) >1.71 (1)
Indicator Value and corresponding score (in parenthesis)Best Good Poor
Applying the Scoring System
Courtesy: Dr. Kefyalew Desta
Soil Biological PropertiesSoil respiration lbs CO2-C/a/d
32-64 (10) 16-32 (7) <16, >64 (4)
Microbial biomass mg C/kg soil
345-700 (8) 200-345 (5) <200 (3)
Earth worm (#/ft2 in holes)
> 15 (7) 5-15 (4) <5 (2)
Indicator Value and corresponding score (in parenthesis)Best Good Poor
Total Score and Intervention
Courtesy: Dr. Kefyalew Desta
Total score
Intervention type Description
>90 Minor new intervention; continue with maintenance to avoid degradation
Look for the indicator with lowest score and intervene with appropriate remediation practices
80-90 Moderate intervention
Look for the indicator with lowest score for each component and intervene with appropriate remediation practices.
<80 Major and immediate intervention is required
Investigate the score of indicators in each component and apply comprehensive best management practices. This level of soil quality warrants the need for raising soil organic matter level.
Online Soil Quality Assessment
This SQA algorithm is under construction
References and Links
United States Department of Agriculturehttp://usda.gov/wps/portal/usda/usdahome
Free Soil Quality Test Kit Guide can be downloaded fromhttp://soils.usda.gov/sqi/assessment/files/test_kit_complete.pdf
Dr. Kefyalew [email protected]
Comment
Questions?Thanks!