Phosphorus Index Based Management Douglas Beegle Dept. of Crop and Soil Sciences, Penn State University [email protected] SUMBER:

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

mailto:[email protected]

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


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


Mengelola Pencemaran Phosphorus

Subsurfaceflow

Tile flow

Leaching

Sources Transport

Erosion

Runoff

N P K

Hydrology Water Body


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


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



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


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


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


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


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


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


Kehilangan P merupakan proses “Landscape” yg kompleks

Subsurfaceflow

Tile flow

Leaching

Sources Transport

Erosion

Runoff

N P K

Hydrology Water Body


Indeks P = Phosphorus Index

P Transport Site Characteristics1. Erosi Tanah2. Kelas Runoff3. Potential Pencucian

1. Drainage bawah-permukaan

4. Contributing Distance5. Modified Connectivity


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


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



75 kg P/ha TSP



Indeks P mendeskripsikan Potensial kehilangan P

Very highHighMediumLow

Sharpley, USDA-ARS

R2=0.79


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.


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


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


Phosphorus Index Based Management Douglas Beegle Dept. of Crop and Soil Sciences, Penn State University [email protected] SUMBER:

Documents

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surface p

high p index

low p index

use p index

medium p index

kehilangan p r

kehilangan p merupakan