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The phosphorus cycle in n orthwest European agricultural soils. Fien Amery Bart Vandecasteele. Nutrihort September 17, 2013. Institute for Agricultural and Fisheries Research Plant Sciences Unit www.ilvo.vlaanderen.be Agriculture and Fisheries Policy Area. Phosphorus in water and soil. - PowerPoint PPT Presentation
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The phosphorus cycle in northwest European agricultural soils
NutrihortSeptember 17, 2013
Fien AmeryBart Vandecasteele
Institute for Agricultural and Fisheries ResearchPlant Sciences Unit
www.ilvo.vlaanderen.beAgriculture and Fisheries Policy Area
Phosphorus in water and soil
2
• Phosphorus (P): negative effects on water ecology (eutrophication)→ Water Framework Directive→ Nitrate Directive
• Target: agricultural P application• Good, but…
– Impact on soil and crops?– Efficient tool?– Differences among Member States?
Literature study
Phosphorus in surface waters
3
Water Framework Directive• Goal: good ecological status/potential of water bodies
• Each member state:– Define ecological reference condition and classifications for
each surface water type– Relate ecology to chemical/physical conditions (P concentration)– P concentration standard for each surface water type
Phosphorus in surface waters
4
Water Framework Directive• Intercalibration exercise between member states• Guidance document (not legally binding)
0
0,2
0,4
0,6
0,8
1
1,2
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Tota
l Pho
spho
rus
(mg
l-1)
MS
Values of the Good/Moderate Boundary of Ecological status in European streams and rivers
EEFI LV UK LT CZ NL FR DE SK PL RO BGES
mean or none (mg l-1)
median (mg l-1)
90 percentile (mg l-1)
IT CYP
Value as EQR
BELU SE
Rivers (Claussen et al., 2012)
Flanders: 0.14 mg P/l + 0.07-0.14 mg ortho-P/l
Phosphorus in surface waters
5
Water Framework Directive
0
0,05
0,1
0,15
0,2
0,25
0,3
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Tota
l Pho
spho
rus
(mg
l-1)
MS
Values of the Good/Moderate Boundary of Ecological status in European lakes
EEFI LV UKLT CZ NLFR DE PL ROBGES
mean or none (mg l-1)
median (mg l-1)
AT SEIT CYP
Lakes (Claussen et al., 2012)
Flanders: 0.03-0.11 mg P/l
Phosphorus in surface waters
6
• Difficult to compare: – Type of concentration– Statistics– Water type– Time of measurement– Monitoring network
Groundwater(points/1000 km²)
Surface water(points/1000 km²)
Belgium 99 38Germany 3 1Denmark 34 5France 5 3Ireland 1 3The Netherlands 33 13United Kingdom 13 33Finland 0.2 0.4average 13.7 7.4
Source: van Grinsven et al., 2012
• Thresholds are exceeded in Europe: – 60% of NiD measuring points in Flanders– 57% of NiD measuring points in the Netherlands
→ P application in agriculture is targeted
Phosphorus in agricultural soils
7
• Phosphorus losses from soil– In general: losses increase with increasing soil P concentration– Often: exponential increase above a threshold P concentration– Important: transport and hydrological factors
→ Keep soil P concentration under thresholdSoil P concentration
yiel
d targetzone
P loss
Phosphorus in agricultural soils
8
• BUT what about crop yields?– Farmers fear smaller crop yields– However: none/small yield reductions expected at P-input < P-
export given the large soil P reserves in NW Europe
Soil P concentration
yiel
d targetzone
P loss
Phosphorus in agricultural soils
9
• Target zone:– optimum crop yields (agro-economical)– Minimal soil P losses (ecological)
– Left of target zone: P input > P export– In target zone: P input = P export (equilibrium fertilisation)– Right of target zone: P input < P export
Soil P concentration
yiel
d targetzone
P loss
How to reach the target zone?
10
1. Sound fertilisation advice• Target zone of fertilisation advice
– often > economic/ecological target zone– Wide variation in Europe
20 40 60 80 100 120 140 160 180 200
Flanders (BE)
Hungary
Lithuania
Norway
Slovenia
Sweden
Soil P concentration (P-AL, mg P/kg soil)
Soil P concentration
yiel
d
targetzone
P loss
Source: Jordan-Meille et al., 2012
How to reach the target zone?
11
1. Sound fertilisation advice• Flanders: highest target zone for fertilisation advice
+ fertilisation advice for target zone soils > P export
Soil P concentration
yiel
d targetzone
P loss
Crop Advise (kg P2O5/ha/yr)a
P-export (kg P2O5/ha/yr)b
Chicory 81 43
Broccoli 130 12
Celeriac 110 67
Leek 113 34
Salsify 103 27
Spinach 131 16
Brussels sprouts 132 33
Carrots 132 62
Strawberry 146 11a Average for the target zone according to the Bodemkundige Dienst België (Maes, 2012)b Average in the Netherlands (Ehlert et al., 2009)
How to reach the target zone?
12
1. Sound fertilisation advice• A need for updated fertilisation advice
– New knowledge and methods– Advice often based on trials from 40 years ago and limited tested
crops• Significant effort! • Example: the Netherlands (see presentation 23)• In addition: farmers often apply more than the recommended
dose
How to reach the target zone?
13
2. Application standards• Phosphorus application standards to limit soil P
concentrations– Most countries: no P limits
a First numbers: for 2013-2014. Numbers between brackets: proposed standards from 2017 on. Standard for phosphate saturated soils: 40 kg P2O5/ha/yr; b Agricultural system: grassland or arable crops; c Standards only for organic P fertilisation
Country (region) Differentiation P fertilisation standard (kg P2O5/ha/yr)
Belgium (Flanders) Crop 65-95 (55-90)a
The Netherlands Soil and agricultural systemb 55-120Ireland Soil and crop 0-286Sweden - 50c
Slovenia - 120c
France (Brittany) Type of farm 183-218
How to reach the target zone?
14
2. Application standards• Differentiation of the P application standards?
– Crop differentiation (Flanders, Belgium): P limit ≈ P-export
– Soil P differentiation (the Netherlands): P limit according to P soil
– Soil P and crop differentiation (Ireland)
Soil P concentration
yiel
d
targetzone
P loss
Soil P concentration
yiel
d
targetzone
P loss
Soil P concentration
yiel
dtargetzone
P loss
Soil P concentration
yiel
d
targetzone
P loss
Soil P concentration
yiel
d
targetzone
P loss
Soil P concentration
yiel
d
targetzone
P loss
How to reach the target zone?
15
2. Application standards• Flanders: no crop
differentiation within the vegetable group: 65 kg P2O5/ha/yr = 28 kg P/ha/yr (2017: 55 kg P2O5/ha/yr = 24 kg P/ha/yr)
• Ireland: standards in kg P/ha/yr
How to reach the target zone?
16
2. Application standards• Flexibility in application standards?
– The Netherlands: 20 kg P2O5/ha/yr transferrable to next year– The Netherlands and Flanders: P application by compost accounts
for only 50%– Not present in legislation: higher application standards when more
than one crop per year is grown
Remarks
17
• Despite attemps to reduce P fertilisation, P concentrations in water bodies remain high– Low mobility of P– Legacy P– Contribution of point sources?– Even if P concentration decreases, ecology not ameliorated
• Alternatives– Targeting point sources– Targeting transport, edge-of-field measures (e.g. chemical soil
amendments, capturing P in wetlands or filters, etc.)
Conclusion
18
• Large differences in Europe– P concentration standards in water bodies– Monitoring– P fertilisation advice– P application standards
• When targeting agricultural P application: P gift should be adapted to soil P concentration and crop demand– Sound fertilisation advice– Differentiated application standards
Soil P concentration
yiel
d targetzone
P loss
Thanks for your attention!
Institute for Agricultural and Fisheries ResearchPlant Sciences Unit
www.ilvo.vlaanderen.beAgriculture and Fisheries Policy Area
Fien AmeryBart Vandecasteele
NutrihortSeptember 17 2013
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