Phosphorus Index Based Management
Phosphorus Index Based Management
Douglas Beegle Dept. of Crop and Soil Sciences, Penn State University
[email protected]://panutrientmgmt.cas.psu.edu
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Why do we need a P Index?Why not just agronomic recommendations?
N P2O5 K2O
Nitrogen BasedCorn/Dairy
Manure
Regional P Balance
¼
¾
Manure
Crops
Soil
AnimalsFeed
Eutrophication
Nutrient flows in
modern ag
P Index
?
Field P Balance
N P2O5 K2O
Phosphorus Based
Corn/Dairy Manure
P Index
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Source Transport
Critical Source Area
Indeks P Critical Source Area Management
1. Overlap of Source & Transport Indicators2. Identify and manage the critical source
areas3. Evaluasi risiko lingkungan4. Target dan Sumberdaya
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Mengelola Pencemaran Phosphorus
Subsurfaceflow
Tile flow
Leaching
Sources Transport
Erosion
Runoff
N P K
Hydrology Water Body
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Mehlich-3 soil P, mg/kg
0 200 400 600 800
P loss,
lb P2O5/A
Uji Tanah vs. Kehilangan P
R2=0.80
0.8
0
1.6
2.4
Sharpley, USDA-ARS
Crop POptimum
P Threshold
No recent P inputs
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Mehlich-3 soil P, mg/kg
0 200 400 600 800
P loss,
lb P2O5/A
75 kg P/ha TSP
112 kg P/ha swine slurry
150 kg P/ha poultry manure
75 kg P/ha TSP
112 kg P/ha swine slurry
150 kg P/ha poultry manure
Uji Tanah vs. Kehilangan P (dengan pupuk P)
Soil OnlyR2=0.80
For all data points R2=0.40
0.8
0
1.6
2.4
Sharpley, USDA-ARS
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Indeks P• P Source Site Characteristics
– Environmental Soil Test P • Same soil test different interpretation
• Sampling Questions?
• P Saturation?
– P Fertilizer• Rate and Appl. Method
– Organic P• Rate and Appl. Method
• P Source Coefficient (PSC)– Direct availability of manure P to runoff
– Based on WEP in manure
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Transport P oleh Erosi-Tanah
Erosion reduced 95%
1980 1985 1990 1995
Conventionaltill wheat
Convertedto no-till
Total P
mg/L
6
4
2
0
-
-
Sharpley, USDA-ARS
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Zone Interaksi dengan Runoff
· Location of applied P· Interaction with
runoff• P on surface• Soil test at surface• High P Saturation at
surfacePsat = P / Al + Fe
Oxalate extr. or Mehlich 3 extr. 100
0 100 200 300 400 500 600
0
20
40
60
80
Mehlich 1 P (mg/kg)
Dep
th (
cm)
Data from Mozaffari and Sims, 1994
Zone of interaction with runoff
Plow depth
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Transpor P-larut dalam Runoff
Conventionaltill wheat
1980 1985 19951990
Alg
al-
availa
ble
P, m
g/L
0.5
1.0
0
Convertedto no-till
Sharpley, USDA-ARS
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Kehilangan P Larut oleh aliran bawah permukaan
Kehilangan P ini sangat tergantung pada sifat-sifat tanah:– Hidrologi
• Piston flow• Macro pores
– Tekstur tanah– Kimia tanah
(Fe, Al, Ca)– P loading/saturation– Drainage Buatan.
Data from: Bolton et al., 1970
Culley and Bolton, 1983
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Kehilangan P merupakan proses “Landscape” yg kompleks
Subsurfaceflow
Tile flow
Leaching
Sources Transport
Erosion
Runoff
N P K
Hydrology Water Body
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Indeks P = Phosphorus Index
P Transport Site Characteristics1. Erosi Tanah2. Kelas Runoff3. Potential Pencucian
1. Drainage bawah-permukaan
4. Contributing Distance5. Modified Connectivity
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
PA
Phosphorus
Index
v 2.0
PART B: SOURCE FACTORS Field ID
SOIL TEST Mehlich-3 Soil Test P (ppm P)
Soil Test Rating = 0.20* Mehlich-3 Soil Test P (ppm P)
FERTILIZER P RATE
Fertilizer P (lb P2O5/acre)
FERTILIZER APPLICATION
METHOD
0.2 Placed or injected 2"
or more deep
0.4 Incorporated <1 week following application
0.6 Incorporated > 1 week or not incorporated following
application in April - October
0.8 Incorporated >1 week
or not incorporated following application
in Nov. - March
1.0 Surface applied to
frozen or snow covered soil
Fertilizer Rating = Fertilizer Rate x Fertilizer Application Method
MANURE P RATE
Manure P (lb P2O5/acre)
MANURE APPLICATION
METHOD
0.2 Placed or injected 2"
or more deep
0.4 Incorporated <1 week following application
0.6 Incorporated > 1 week or not incorporated following
application in April - October
0.8 Incorporated >1 week
or not incorporated following application
in Nov. - March
1.0 Surface applied to
frozen or snow covered soil
P Source Coefficient
Refer to: Test results for P Source Coefficient OR Book values from P Index Fact Sheet Table 1
Manure Rating = Manure Rate x Manure Application Method x Manure P Availability
Source Factor Sum
PART B: TRANSPORT FACTORS Field ID
EROSION Soil Loss (ton/A/yr)
RUNOFF POTENTIAL
0 Excessively
2 Somewhat Excessively
4 Well/Moderately Well
6 Somewhat Poorly
8 Poorly/Very Poorly
SUBSURFACE DRAINAGE
0 None
1 Random
2* Patterened
CONTRIBUTING DISTANCE
0 > 500 ft.
2 350 to 500 ft.
4 200 to 349 ft.
6 100 to 199 ft. OR
<100 ft. with 35 ft. buffer
9‡ < 100 ft.
Transport Sum = Erosion+ Runoff Potential + Subsurface Drainage + Contributing Distance
MODIFIED CONNECTIVITY
0.85 50 ft. Riparian Buffer APPLIES TO DIST
< 100 FT
1.0 Grassed Waterway or
None
1.1 Direct Connection APPLIES TO DIST
> 100 FT
Transport Sum x Modified Connectivity/24
P Index Value = 2 x Source x Transport
Field ID
Is the CMU in a Special Protection Watershed?
Is there a significant farm management change as defined by Act 38? If the answer is yes to any of these
Is the Soil Test Mehlich-3 P greater than 200 ppm P? questions Part B must be used.
Is the contributing distance from this CMU to water less than 150 ft.?
* OR rapid permeability soil near a stream ‡ "9" factor does not apply to fields with a 35 ft. buffer receiving manure.
PART A: SCREENING TOOL
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
0.4
0
0.8
1.2
P loss,
kg/ha
P index value for the site
0 50 100 150 200
75 kg P/ha TSP
112 kg P/ha swine slurry
150 kg P/ha poultry manure
75 kg P/ha TSP
112 kg P/ha swine slurry
150 kg P/ha poultry manure
Indeks P mendeskripsikan Potensial kehilangan P
Very highHighMediumLow
Sharpley, USDA-ARS
R2=0.79
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Indeks P = Phosphorus Index1. Low P Index
1. N Based Management
2. Medium P Index1. N Based Management
3. High P Index*1. P Based: Crop removal
4. Very High P Index*1. No P: Manure or Fertilizer
High and Very High*– Modify Management
based on P• No or reduced manure
• Change time or method of application
• Conservation practices
• Buffers
• Etc.
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Rencana Manajemen Hara P
• Develop N based plan– Usually means excess P will be
applied
• Use P Index to evaluate the N based plan – Is the risk of P loss acceptable
• Acceptable risk– Apply @ N rate, excess P
• Unacceptable Risk– Modify N based plan, where
necessary, to address P loss risk
N P2O5 K2O
Nitrogen BasedCorn/Dairy
Manure
N P2O5 K2O
Phosphorus Based
Corn/Dairy Manure
or
or
NONESUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
Aplikasi Indeks P
• Eventually, all fields will have a high P index
• P Index is not the solution– Tool to buy time to solve problem– Minimizes negative impact of P while we
come up with a sustainable solution– We need to get the system into better balance
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt
NRCS/EPA P Index Issues
• Proposed change in NRCS 590 Std.– P soil test only – No more P Index
• Easy to regulate • Very strict limits• Not supported by the science - Source/Transport• Unrealistic for animal agriculture to comply with in
short term• Better soil P balance is a good long term goal
– Withdrawn, under further review
SUMBER: aesl.ces.uga.edu/MidAtlantic/2010/P%20Index-%20Doug%20Beegle.ppt