An industry approach and recommendations…Nutrient performance indicators and nutrient use efficiency

Rob Norton & Tom Bruulsema, IPNI ANZ/NEA on behalf of IPNI

The role of IPNI……….

• to develop and promote scientific information about the responsible management of plant nutrition for the benefit of the human familyOur stakeholders-• Member companies, scientists, advisors and farmers.This approach -• The perspective presented here is to consider how nutrient

performance indicators – such as removal/use ratio (Partial Nutrient Balance) can be use to promote responsible management of plant nutrients (in this case N)

• AND enhance food security and soil health.

Why indicators? – The importance of farmers

• Measure and improve systems– indicators of management – improved by farmers through policy– statements of accountability – regional/national government

• Grain production water use efficiency– Water limits yield– Management targets WL Yield– Benchmark 20 kg/ha/mm seasonal rain– Every farmer & advisor has this target.

Frechn & Schultz, 1984

Why indicators? – The importance of farmers

• Measure and improve systems– indicators of management – improved by farmers through policy– statements of accountability – regional/national government

• Nutrient Performance versus Nutrient Efficiency– We all to be more efficient – but how– Efficiency is one aspect of nutrient performance– Performance is a more appropriate term– Efficiency is not always fundamental to system improvement.– Effectiveness is what farmers consider - not efficiency.

• IFA Nutrient Stewardship Working Group

• TFI Sustainability Task Force• CFI Nutrients Committee• EU Nitrogen Expert Panel • International Nitrogen Initiative

Key considerations for Nutrient UseEfficiency (NUE) as a performance metric

• Many ways - Partial Nutrient Balance (output/input ratio)• Optimum - neither too high nor too low• One of a complement (NUE + Yield + Soil Fertility)• Data - availability and timeliness of reporting• Trend - past, present, future• Nutrient - N, P, others• Targets - set regionally, not globally• Interpretation in site-specific context• Engage with farmers to develop aggregated values• Incorporate uncertainty into the measures

IFA, June 2014IPNI, August, 2014

Complementary sets of nutrient performance indicators

Enablers(process metrics)

Actions(adoption metrics)

Outcomes(impact metrics)

• Extension & professionals

• Infrastructure

• Research & innovation

• Stakeholder engagement

[Require regional definition of 4R]

• Cropland area under 4R (at various levels)

• Participation in programs

• Equity of adoption (gender, scale, etc.)

• Food & nutrition security

• Productivity

• Nutrient use efficiency

• Land quality, soil health

• Air & water quality

• Economic value

• Land conservation, natural habitat

DRAFT

Will any one indicator be useful• The purpose of using nutrients is

to grow food, feed, fiber and fuel.

• Need to link nutrient performance to

– Productivity (eg yield gaps)– Potential losses to the

environment– Change in soil nutrient status

• One number cannot convey that complexity.

Form of expression –NUE can be defined and calculated in many ways

NUE term Calculated from Typical levels for N(maize or wheat)

PFP Y/F 40-80

AE (Y-Y0)/F 10-30

PNB R/F >100% = deficiency<100% = surplus

RE (U-U0)/F50% (whole-plant)33% (grain only)

Y=yield, F=fertilizer, R=removal, U=uptake

… but always, a ratio of output/input

Dobermann, 2007

What information do these terms convey?

• PFP – How productive is this crop (cropping system) in comparison to its nutrient (fertilizer) input.

– By definition this declines with increasing nutrient input

• PNB – How much of the nutrient is removed in product relative to the amount of nutrient (fertilizer) applied.

– defines one of several transfer processes.– It is not necessarily an environmental indicator.– Can also be indexed by area/product

• eg /ha or /t grain• Intensity measurement

Based on data from Cassman et al., 2002

Assessing impact on short term crop uptake and long-term soil nutrient supply is critical in evaluation of system efficiency

Midwest Corn - NUE improvement

12% increase in N fertilizer use51% increase in N efficiency

Since 1975: Data sources:

USDA Ag Chem Use Survey & Annual Crop Production.

197540 kg grain/kg N

200870 kg grain/kg N

Efficiency & Effectiveness for farmers

• PFP & PNB decline with increasing inputs• Economic response - marginal cost versus marginal return

– Cost of input compared to value of output – Near Ymax

Yield Gap

Metrics for productivity, yield gap, and yield gap arising from crop nutrition are difficult to measure

Pasuquin, JM et al. 2014 Field Crops Research 156:219–230

Maize in Southeast AsiaYield Gap, Attainable – Farmer Practice, t/ha

0.7 0.9 1.1

N in grain systems – indicators of value

• Canola/Wheat/Barley/Pulse (70 kg Ndfa/ha)

Time1996-2013

N balances/productivity @9 kg P/ha

t/ha PFP PNB* $/ha OC%

Annual N rate

(kg N/ha)

0 1.95 - - 258 1.18a

20 2.30 109 2.94 275 1.24a

40 2.31 58 1.60 291 1.27a

80 2.31 28 0.92 298 1.25a

160 2.46 14 0.47 202 1.26a

* N only from fertilizer

Removal to Use Ratio (PNB)

• Widely referenced (IFA, SDSN, INI, etc)• Scalable from field to farm to region to

nation.• It is a ratio, does not have yield nor scale

of balance (ie impact)

• Quality of and confidence in input data

PNB = Nutrient Removal / Fertilizer Nutrient Supplied

NR = Nutrient concentration * Product Removal

NS = Fertilizer applied

Nutrient concentrations –Wheat grain N concentration -

Location/Type

MC %

N (kg/t FW)

n Ref

Spring ns 21.0 ns IPNI

Winter ns 19.0 ns IPNI

Hard Winter ns 20.5 ns NRCS

Soft Winter ns 17.0 ns NRCS

Aus 11 21.0 ns IPNI

Qld 1991-1999

11 21.1 13 QDNR

Vic 1995-1998

11 17.4 106 Pivot Grain

Barraclough, P.B.et al. 2010. Eur J Agron 33, 1-11.

Values for Grain Nutrient Concentrations

2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 6.500%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Canola Grain N (0% MC)

• Survey of Australian Canola grain from national variety trials, 2013.• Mean 4.28% ±0.62. CV 14%• Significant regional differences – eg within South Australia – 3.69 to 4.96• Immediate uncertainty in the PNB derived from these figures.

Disaggregated fertilizer use by crop data

• IFA publications– 2 publications only, 2006 23; 2010 - 27

• FAOstat – total include pastures– Lasseletta attempted to disaggregate using a pasture & N use trendline

• US – good quality data at regional level from industry but not by crop.

• IPNI – NuGIS, AgStats, Australia, Brazil & India• Australia – farm survey data of fertilizer use by farm type, and

regional industry values.

Australia – N Use and PNB by Industry

Type Nin 2007/8 (kt) N PNB Area (Mha)

Horticulture

Vegetables 12.6 0.61 0.8Grapes 6.0 0.61 0.9Pome Fruit 0.7 0.47 0.1Stone Fruit 0.5 0.57 0.1Citrus Fruit 1.6 0.37 0.1

Livestock

Sheep 22.6 1.50 41.3Beef 31.5 3.12 260.6Dairy 62.1 0.85 2.6Sheep/Beef 7.7 2.61 29.7Mixed 107* 1.65 21.8

Grains

Rice 1.1 0.98 0.2Grains 335 1.63 27.7Cotton 24.2 0.53 0.8

Sugar Sugar 24.7 0.95 0.7Total Sum 637.3 1.52 387.4

• Farm Survey• Uncertainty

• 850 kt N sold (FA)

• “Crops”78% N useVegies – ManuresMean N = 15 kg/haPNB 1.58

* N mainly used on cropping activities

Scale of fertilizer use data – eg Muller et al. Nature 490, 254

• .k

50 kg N/ha

Current estimates using public data.

• FAOStat – crop production data 2006, 2010. From their on-line database. What constitutes a CROP – Sugar? Oilpalm?

• Fertilizer use by crop – derived from IFA publications covering 2006/7 and 2010 FAO stat not disaggregated.

• Crop nutrient concentrations from IPNI crop

All cereals: N partial nutrient balances

Crop PNB

Wheat 0.74

Rice 0.56

Corn 0.55

Other 1.23

Annual oilseeds – N partial nutrient balances

By ranking – lower quartile, upper quartile

PNB among crops

Crop Production (Mt)

Area (Mha)

PNBkgNr/kg Na

Wheat 602 211 0.76

Rice 639 155 0.56

Corn 707 147 0.55

Other Cereals 286 165 1.23

Oilseed (annual) 98 68 0.73

Soybean 243 99 14*

Oilpalm (FFB) 210 14 0.81**

Sugarcane (cane) 2700 38 0.89 **

What value is it to know the differences among crops for PNB?

• Excluding BNF** Excluding recycled nutrients from processing

How to consider fixed N -

• ~100 Mha of soybeans– 950 kt of N applied – 1/3rd of that on 8 Mha in China– 55 kg N/t – so 240 Mt removes 13,000 kt N

• Do we assume soybean to be N neutral?– Salvagotti et al, 2008 FCR

• ON AVERAGE 50-60% of soybean N demand is met by BNF• 80% PNB suggested

– Peoples et al. 2009 Symbiosis• Suggests 68% of soybean N demand is met by BNF

• Gross Ndfa of around20 Mt in food legumes.– Explicit assumptions in dealing with these.

• Legume based pastures/alfalfa in rotations -

The particular role of pastures

• Not uncommon to have cropping systems incorporating short or long term legume pasture phases

• Significant contribution to N economy – example Australia (Angus 2001 AJEA)

– Fixed N by pastures – 1,320 kt– Fixed N by crops – 235 kt– Atmospheric deposition - 160 kt– Fertilizers – 750 kt

• Should annual sown pastures be included as crops?

Allocation to BNF eg Lassaletta et al. 2014 Environ. Res. Lett, 9, 105011

70% 30%

Not a criticism of this paper, it is comment on the adequacy of data to undertake regional assessments.

The assumptions were clearly stated and reasonable on the basis of the information used.

Understanding other inputs/outputs

• Use of “Mill Mud” in sugar cane – PNB 0.93– Recycle 150 t/ha onto fields – 120 kg N– Cartage costs means uneven return.

• Burning or removing crop residues– Wheat straw = 0.5 kg N/t NHI ~0.8-0.9 (linear?)

• Burned = 70% lost• Carted for biofuel or similar – 100% loss

• Use of manures and composts as nutrient sources.

Nutrients on Dairy Farms – example for N kg/ha

Gourley et al. 2012. APS

Silage 7.5(0-103)Hay 11.2(0-223)Conc 52.5(0-222)Fert 104(0-424)Animal 4.6(0-62)Irrig/Air 0.1(0.1-15.9)N fixation 16.6(0-289)

Milk 58.3(17-190)Animal 11.8(0.2-78.1)Forages 0(0-11)Manure 0.0(0-0)

NUE+192.8 kg/ha17.0 g/L

70/196 35%70/104 65%

Numbers in kg/ha

Nutrient Performance Indicators• Need to be:

–Systematic in their estimation–Scalable

• national, regional• relevant to farm and field scales also

–Transparent and referenced– Assumptions explicit (fertilizer, fixed, manures).– Include an assessment of confidence.–Capable of repeated measures – frequency?

IPNI Metrics• North America: NuGIS & Soil Test Summary

Figure 4.1: Inputs of N to US agricultural land, including recoverable manure, legume fixation, and commercial fertilizers, as compared to removal by crops (adapted from IPNI NuGIS, 2011). [In Robertson et al., 2012, Biogeochemistry]

NuGISUSA 2012, partial P balance, removal/use

NUE varies spatially

NuGIS, 2014

NUE varies temporally – prices and weather

Frequency distribution of soil test P

Relationship of STP with PNB, 12 corn belt states

All Agriculture (Crop + Livestock) Removal/Fertilizer, N

New South Wales Victoria Queensland Western

Australia South

Australia Tasmania NT Australia

2.05 2.49 1.08 1.48 2.28 1.25 4.20 1.76

P

N

Australia Nutrient Balances

N - PFP

Fixen et al. 2014

PFP @ particular yields

N - PNB

Fixen et al. 2014

NUE trajectories over 48 years

↑ yieldstable PNB

Lassaletta et al., 2014, Environ. Res. Lett. 9 (2014) 105011 (9pp)

PNB 100%

PNB 47%

Going beyond a number

Contrasting trajectories

Lassaletta et al., 2014, Environ. Res. Lett. 9 (2014) 105011 (9pp)

Yield highIncrease slowingLowering of NUE

Yield increasingIncrease high

Increase of NUE

Yield lowIncrease coming

High NUE

Challenge - Translate into farmer practice, ie $ and yields

Australian growers know about WUE 20 kg/ha/mmWhat is the nitrogen use efficiency?

– Partial Factor Productivity– Partial Nutrient Balance

• 4R practices linked to these indicators.

Region Cereal PFP

kg gr/kg N

Cereal PNBkg N / kg N

Australia 52 0.82

North America

45 0.68

SS Africa 123 1.89

East Asia 32 0.46

World 44 0.66

Mean is interesting but not informative

• Accounting for nutrients –– Whole farm balance – 192 kg N/ha (47-601)– Productivity balance – 17 kg N/L (9-45)– Removal to Input – 25% (14-50)– Fertilizer N 53% of N inputs

• 102 dairy farms in NY– Cela et al. Cornell– 5 year study – buy-in– target of N balance at which 75% of farms

• 102 kg N/ha– 4R nutrient management– Feed management

Importance of Farm Scale Assessments

• Fertilizer is used within a farming system– Farms are more important than crops or fields or regions – Nutrient management in done across crops in rotations

• Fertilizer use is an agronomic & economic decision – Decision is based on a response curve & the yield gap– But removal to use ratios are largely irrelevant to farmers

• Better nutrient performance will rely on engagement with farmers

– Where the rubber hits the road.

Disaggregating data and indicators

• Compromise between scale and precision– can have an approximate answer at a very broad scale (policy)– can have a precise answer at a narrow scale (management)

• Farmers are when interventions to alter removal to use metrics occur

– Right Source – enhanced efficiency sources– Right Rate – to match the economic optimum?– Right Time – to match plant demand– Right Place – where losses are least

Summary: Farm scaled, linked to soil, productivity, environment & adoption

• Global sustainability initiatives demand metrics.• Nutrient performance is more than NUE; it includes

productivity and soil health; requires complementary metrics.• Forms of nutrient use efficiency vary – clarify units.• Source, time and place, as well as rate, impact nutrient

performance.• Aggregating farm scale data will help farmers balance yield,

efficiency and soil health.• “Nutrient use efficiency is a useful, complex, and

incomplete indicator of crop nutrition performance”

Challenge: availability & reporting of data

Formed in 2007 from the Potash & Phosphate Institute, the International Plant Nutrition Institute is supported by leading fertilizer manufacturers.

Its mission is to promote scientific information on responsible management of plant nutrition.

ThankYou

www.ipni.net