The Impact of Achieving Targetsset out in Food Harvest 2020 on Nitrogen and Phosphorus Usage

Noel Culleton

Food Harvest 2020 Targets

Increase value of primary output by € 1.5 billion

50% increase in milk output

Increase in output value of 20% in beef and sheep

No targets for cereals

Principles and Issues around Sustainable Fertiliser Usage

Maximising output from grassland

Soil phosphorus (P) balances and spreading strategies

Environmental challenges to FH 2020

Maximising Output From Grassland

Grass grazed efficiently is cheapest feed source

Remain competitive by reducing concentrate and silage fed

Productive grassland depends on adequate soil fertility

“To achieve FH 2020 targets by maximising grass output, rather than increasing concentrate feed,

means that maintaining soil fertility is vital”

Soil Nutrient Balances and Fertiliser Strategies

Table 1. The Phosphorus Index

Soil P IndexSoil P Range

Grassland Other Crops

1 < 3.0 < 3.0

2 3.1-5.0 3.1-6.0

3 5.1-8.0 6.1-10.0

4 >8.0 >10.0

Phosphorus maintenance and build up

Concept of P balance

P balance and stocking rate

Environmental Challenges to FH 2020

Grassland and nutrient cycling

Environmental issues:

Water quality

Climate Change

Biodiversity

Water Quality

Nitrates Directive vs.

Water Framework Directive

Negotiations on water quality vs.

Increasing fertiliser use - (P balance)

Source verification

Climate Change

Proportionate burden sharing across sectors poses a threat to 2020 targets

This threat must be challenged:

No increases in stock numbers (FAPRI)

Emissions per kg of product are low

Forestry may help resolve issue

More efficiencies to be found in farming

Biodiversity

Will a reduction in biodiversity pose a threat to achieving targets ?

unlikely!!

Template needed to find local solutions to local problems, with mechanisms for cost benefit analyses

Nationally, stocking rates are still low

More regulation in high conservation areas

Opportunities for more biodiversity on intensive farms

Predicted Impact of FH 2020 on Phosphorus Usage

Methodology:

1. CSO data for milk and beef in reference years (2007-2009)

2. 50% increase in milk sales

3. FAPRI data used for beef and sheep production in 2020

4. P offtakes as reported by Coulter and Lalor (2008)

5. Cereal production in 2007-2009 as recorded by CSO

6. Cereal production in 2020 as predicted by FAPRI

7. Calculations based on p balance - adequate soil p status is assumed

P offtakesTable 2. Estimated Phosphorus Offtakes (tonnes per year) in Milk, Beef

and Tillage

Production Type

Phosphorus offtake (tonnes)

Reference Years 2020Change in P

offtakes

Tillage* 8,301 6,953 -1,348

Meat 10,860 11,400 +540

Milk 4,934 74,01 +2,467

Total P offtake 24,095 25,754 +1,649

% Change +6.9% *Tillage figure based on FAPRI estimate of 18% reduction in tillage area

P offtakes kg/ha/yr in each enterprise Beef 4-6 kgMilk 10-14 kgTillage 30-40 kg

Soil P Fertility

Table 3. % of Soils in each Soil Index Category 2001-2011

Index 2001 2005 2007 2009 2010 2011

1 17 18 14 18 21 24

2 23 25 27 26 28 30

3 27 27 29 28 26 24

4 33 30 30 28 25 22

Source: Plunkett 2012

Future Soil P Fertility

Table 4. Speculative data on soil P status from 2007 to 2020, based on estimated data and linearly extrapolated projections

from Table 3

Index 2007 2011% change per year

2020 (Projected)

1 14 24 +2.5 47

2 27 30 + 0.8 37

3 29 24 -1.3 13

4 30 22 -2.0 4

Implications of Poor Fertility

1.5 t DM per ha less at Index 1 than at Index 3 (Teagasc)

Table 4 implies that an additional 750,000 ha of grassland will revert to Index 1

Therefore there will be approx. 1 million tonnes of grass DM less than current output

If output is to be maintained, extra concentrates must be fed

Issues that need to be addressed

Phosphorus is a finite resource (Cordell et al.,2009)

Sustainable P usage by farmers

Water quality cannot be ignored

More knowledge:

Soil chemistry

P recycling

Soil type and recommendations

Overland flow prevention measures

Predicted Impact Of FH 2020 on Nitrogen Usage

Predicted livestock numbers

Predicted changes in land use in 2020

Predicted fertiliser nitrogen for grazing livestock in 2020

Livestock Numbers

Table 5. Predicted Livestock Numbers in 2020

‘000 HeadReference

YearsFH 2020 % Change

Total Cattle 6487 5715 - 12 %

Dairy cows 1065 1381 + 30 %

Other cows 1165 925 - 21 %

Total Sheep 4250 5020 + 18 %

Source: FAPRI-Ireland Predictions, Donnellan and Hanrahan,2011

Land Use Change

Table 6. Predicted changes in % of land used by different enterprises in 2020

EnterpriseReference

YearsFH 2020 % Change

Dairy 30.1 % 35.5 % + 18 %

Cattle 46.7 % 43.0 % - 8 %

Sheep 13.8 % 13.8 % 0 %

Tillage 9.4 % 7.7 % - 18 %

Sources : FAPRI 2011 ; Farm Management Survey 2011; Fertiliser Use Survey 2008

Assumptions and Calculations

Farmers moving out of beef and tillage will move into dairying

The extra land available to dairying will moderate stocking rates to a 10 % increase

Stocking rate increases will occur across all stocking rate groupings

Table 7. Nitrogen Fertiliser Use on the Dairy Grazing Platform under FH 2020 Scenario Reference farm profile FAPRI-Ireland FH 2020 Scenario

2007-2009 (Increase in dairy cow numbers by 30%)*

Farm Stocking

Rate Grouping

Mean Stocking

Rate

Number of Dairy

cows# N fert. Advice

Actual N fert.

use Stocking

Rate

Number of Dairy

cows

New N fert.

Advice

Change in N fert. Advice

Predicted N fert.

use

kg ha-1 Organic N

kg ha-1 Organic N kg ha-1 kg ha-1

kg ha-1 Organic N kg ha-1 % kg ha-1

<100 90 53,319 40 35 99 69,118 44 110% 38

100-130 115 122,715 93 76 126 159,077 107 115% 87

130-170 150 494,280 141 106 165 640,739 174 124% 131

170-210 190 290,558 237 168 209 376,653 279 118% 198

210-250 230 79,141 279 199 253 102,591 279 100% 199

>250 270 25,320 279 145 297 32,822 279 100% 145

Overall Change in N fertilizer use (weighted average) 118%

Total Cow Numbers 1,065,333§ 1,381,000* # Number of dairy cows per stocking-rate band calculated from Fertilizer Use Survey data (Lalor et al., 2010) § Mean number of dairy cows in reference years was calculated from CSO data (www.cso.ie) * FAPRI-Ireland dairy cow number predictions (Donnellan & Hanrahan, 2011)

Nitrogen Projections

Mean N use for dairying will increase by 18 %

50% of cows will be in the 130-170 kg/ha of organic N grouping resulting in a 24 % increase in N usage

More scope for lowly stocked farms (<170 kg/ha of organic N) to increase cow numbers compared to highly stocked farms due to land availability and Nitrate Directive restrictions.

Significant increases in cow numbers at high stocking rates, requiring derogations.

Nitrogen Fertiliser

Table 8. National Nitrogen Fertiliser Use

2007-09 mean N fert use

(kg/ha)

2007-09 distribution of total N fert use

FH 2020 mean N fert use

(kg/ha)

FH 2020 change in total N fert

use

FH 2020 distribution of total N fert use

Dairy 112 53 132 118 64 %

Cattle 28 21 28 100 16 %

Sheep 30 7 30 100 6 %

Tillage 137 20 137 100 14 %

Weighted Mean

95 110

FH 2020 Total N Fertiliser Use (% of reference years) 116 %

Summary and Conclusions (1)

1. There will be 2,467 extra tonnes of p removed per year from dairying. To maintain soil fertility this must be replaced

2. Due to the projected decline in area under tillage p use should decline by approx 17 %. this may be a pessimistic view

3. Modest increase in P usage in beef systems - approx. 540 tonnes per year

4. Over all increase in P usage in use of 6.9 %

5. The % of soils in Index 1 and 2 have increased from 40 % to 55 % in the last 5 years

Summary and Conclusions (2)

6. If we extrapolate this decline to 2020, there will be 47 % of soils in Index 1 and 37 % of soils in Index 2

7. There is a decline in yield of 1.5 t DM/ha/yr from Index 3 to Index 1. This means a reduction of 1 million tonnes of grass DM per year, should this decline continue. Extra concentrates will be required to replace this grass This will result in a decline in competitiveness

8. Need for an awareness campaign to highlight the importance of P to the industry. Point out that there need not be a deterioration in water quality when

P usage is increased, if good farm practice is adhered to

9. Urgently need more technical information on P cycling/ chemistry/ recommendations and measures to prevent overland flow

Summary and Conclusions (3)

10. Trends in n use are more difficult to predict

11. 18 % increase in N use in dairying, due to increases in stocking rates

12. Little change in n usage in beef or sheep

13. Decline in N use in tillage, due to predicted reduction in tillage area. This scenario may not arise

14. Nitrogen use in the whole sector is projected to increase by approximately 16 %

15. The major change is in the dairy sector

16. In 2007-09, Dairy used 53% of the total N. By 2020,dairying is projected to use 64 % of the total N

Summary and Conclusions (4)

17. Research on improving N recovery/ recycling needs to be expanded

18. The projected fertiliser increases in usage in this paper can be achieved without breaking the Nitrates Directive regulations. The P increases are due to increased output and maintaining P balances

19. The extra nitrogen is needed to maintain the increased stocking rates that are still within the organic nitrogen thresholds outlined in the Nitrates Directive.