Reading the tea leaves - nutrient trends in Australiaanz.ipni.net/ipniweb/region/anz.nsf/0... · 2019-03-27 · Reading the tea leaves - nutrient trends in Australia Rob Norton, ANZ

Reading the tea leaves

- nutrient trends in

AustraliaRob Norton,

ANZ Regional Director, IPNI

Prediction is very difficult,

especially about the future.

Neils Bohr

Agronomy Community, April 14, 2011

Better Crops, Better Environment … through Science

Nutrient Issues in Australia

• Big picture issues

• Understanding of nutrient balances

– Desktop study building on the NLWA 2001

– Data in this study was collected 1994 to 1996 – most recent information!?!?

– Some P balances done more recently

• Gourley – Dairy farms, Cordell – Continental, Wong – WA (unpublished as yet)

WA SA Vic Tas NSW Qld

N +/~ ~/- - + ~/+ ~/-

P ~/+ ~ -/~ + ~/- -

K - - - ~ - -

S +/~ ~/+ ~/+ + ~/+ -/~

Nutrient Imbalances – a big part of the challenge in an open system

Vitousek et al., 2009, Science

Manure composition changes due

to distillers grains

Climate change induced shifts in

cropping patterns, yields, soil

processes

Changes in crop species due to

bioenergy

Application of bioash

Changes in plant parts harvested

due to bioenergy

Major changes in fertilizer costs or

crop prices

Genetic changes that alter crop

yields and NUE

Government policy

P removal to use

ratio by 8-digit

hydrologic unit

1987

2007

Applications of NuGIS

• Guidance in nutrient management education

• A basis for science-based guidance in marketing of fertilizers and nutrient management related services

• A tool for integrating nutrient balances in water quality and nitrous oxide emission modeling

• Factual spatial and temporal input into environmental policy development involving plant nutrients

Being considered for India, Canada, Brazil, others

Case study from the ANRA Audit – Victorian Dairy

All nutrients were in positive balance

Nutrient and sediment loss from horticulture

• Runoff from a small vegetable production enterprise in the Hawkesbury catchment (NSW).

• Measured water, N and P loss from the study area.

• Over 2 years losses were:

• 19 t sediment/ha/y sediment

(1” topsoil)

• 11 kg P/ha/y (on soil)

• 127 kg N/ha/y (in water)

• Bareness over summer and large

nutrient loads associated with

high losses.

E. Hollinger et al. / Agricultural Water

Management 47 (2001) 227±241

Farm gate N & P balance

Farm gate K & S balance

Nutrient and sediment loss from horticulture

• Runoff from a small vegetable production enterprise in the Hawkesbury catchment (NSW).

• Measured water, N and P loss from the study area.

• Over 2 years losses were:

• 19 t sediment/ha/y sediment

(1” topsoil)

• 11 kg P/ha/y (on soil)

• 127 kg N/ha/y (in water)

• Bareness over summer and large

nutrient loads associated with

high losses.

E. Hollinger et al. / Agricultural Water

Management 47 (2001) 227±241

Nutrient balance survey - 2002-2009

• Desk-top audit

• Based on ABARE production figures – 2002 – 2009

– State & Small area data (NRM Zones)

• With nutrient densities as proposed by Reuter (used on ANRA survey).

• Estimated a farm gate nutrient removal in product.

• Using FIFA fertilizer input figures – 2002 to 2009

– State figures only

• P, K and S only estimated – to look at N need to estimate N fixation rates

• THIS IS A WORK IN PROGRESS AND RESULTS ARE PRELIMINARY

State by State P removals at farm gate – 2002-2009

0

50

100

150

200

250

300

NSW Vic Qld WA SA Tas NT

kt

P r

em

oved

Fruit Grain Livestock Sugar Vegetable

0

100

200

300

400

500

600

NSW Vic Qld WA SA Tas NT

kt

K r

em

oved

Fruit Grain Livestock Sugar Vegetable

State by State K removals at farm gate -2002-2009

• No K return for sugar included in this balance – a significant proportion of K is likely to be returned to cane fields as various mill byproducts.

P & K Balance – by State (2002-09)

NT

+1 kt P

0 kt K Qld -3 kt P

WA +81 kt P -36 kt K

-3 kt K

SA +45 kt P

-33 kt K NSW +69 kt P

-62 kt K

Vic +73 kt P

-25 kt K

Tas +13 kt P +11kt K

Nationally

P +278 kt

K -149 kt

P & K Balance – by State per fertilized hectare (2002-09)

NT

+11.7 kg P/ha

-4.6 kg K/ha Qld -1.2 kg P/ha

WA +12.7 kg P/ha -14.9 kg K/ha

-0.4 kg K/ha

SA +2.6 kg P/ha

-1.9 kg K/ha NSW +7.6 kg P/ha

-6.9 kg K/ha K

Vic +9.3 kg P/ha

-3.2 kg K/ha

Tas +22.0 kg Pha +18.3 kg K/ha

Nationally

P +6.4 kg P/ha*

K -3.4 kg K/ha*

* per fertilized ha ABS 2006-07 Census

• No K return for sugar included in this balance – a significant proportion of K is likely to be returned to cane fields as various mill byproducts.

Dahlen IPL Trial Long Term P –long term P management

Soil P 1996

Soil P 2007

Estimated P balance/year

2010 Canola – P Removal1.44 t/ha 2.76 t/ha 3.07 t/ha 2.89 t/ha7 kg P 17 kg P 21 kg P 22 kg P

Colwell P values – IPL labs (<160 PBI)

Location and Soil Type

Colwell P

(mg/kg)

<20 20 to 35 >35

Harden Red & Brown Loams 10% 19% 71%

Horsham Grey & Brown Clay Loams 24% 32% 44%

Maryborough Red & Brown Clay Loams 10% 28% 62%

Cummins Red & Brown Sandy Loams 4% 45% 51%

Moree Gray &Brown Clay/Clay Loams 82% 13% 6%

Dalby Gray &Brown Clay/Clay Loams 62% 25% 13%

Emerald Gray &Brown Clay Loams 52% 14% 34%

Gunnedah Gray &Brown Clay Loams 14% 37% 49%

Huge district variation in soil P levels –

emphasises the need for soil testing

Phosphorus BMP for wheat

• Developed along with a N BMP

• From a GRDC collaborative project

• Key issues are soil testing to know if the paddock is in P balance or not.

• Fertilize to replacement + demand from soil PBI

• Soil test important

– Better Fertilizer Decisions Crops

– Robust calibrations

– Good sampling

From soil test values to investments

How much P to apply?

• Maintenance of fertility = keep same DSE and Colwell P

How much is needed to meet the present stocking rate demand?

0.5 kg P/DSE - exported in produce

0.3 to 1.0 kg P/DSE lost through leaching, soil erosion

0.1 kg P/DSE in soil fixation (PBI)

Pasture type/rainfall /grazing system

• Increase in fertility = increase DSE and Colwell P

How much is needed to raise the test value to meet the extra demand?

Soil test response to added P

• eg 100 PBI – 2.7 kg P to raise Colwell 1 unit.

• eg 300 PBI – 3.0 kg P to raise Colwell 1 unit.

For example

- 0.9 kg

P/DSE

100 wethers

= 1 t of SSP

Changes in soil K test levels – ANRA v IPL Lab 2010

• ANRA Audit up-scaled soil test values to regional value

• 9 Mha with test levels below 120 mg/kg = 10% of area

• Lowest values in WA (25%) & Qld (12%)

State <40 40-80 80-120 120-200 200-400 400-600 >600

Vic 3% 9% 12% 24% 33% 11% 8%

SA 4% 13% 11% 20% 26% 14% 12%

QLD 18% 30% 12% 12% 19% 7% 3%

NSW 1% 4% 17% 9% 41% 18% 9%

TAS 3% 9% 19% 30% 30% 4% 5%

% less 120

11%

16%

25%

44%

18%

No surprises here then

• Declining K use nationally (& NZ)

• Not quite as drastic as the figure @ left

• WA still the big K state

• Largest negative balance in Qld

• Review K use in Qld –Mike Bell project on K & P profile enrichment

S Removal in Australian Agriculture48% removed in Grains, 42% in Livestock

Notional farm gate S balance

• S inputs from current fertilizers – Most superphosphate applied to pastures. DAP/MAP used for grain

• Notionally Australia is in positive S balance

• Not included in this balance

– Added S from mined/biproduct gypsum (4 Mt mined)

– Atmospheric input 4.5 ± 2.1 kg S/ha/y (NLWA 2001)

– S input from irrigation – depends on watershed position

247 kt S/y

+2.9 kg/ha/y

113 kt S/y

Soil S levels – ANRA Audit 2001

• Nationally

11% < 5 mg/kg

• New South Wales

25% < 5 mg/kg

• Victoria

3% < 5 mg/kg

Draws on data from mid-1990’s

Requires revision and review – current IPNI ANZ project

KCl-40

(mg/kg)

Crop Pasture

<8 52% 43%

8-12 20% 30%

>12 28% 27%

2010 Soil S test values (top 10 cm) for Victoria, South Australia,

New South Wales (~1200 tests)

Soil S levels – 2010 (Pre-sowing ie before May 2010)

Location and Soil Type

KCl 40 Wheat

(mg/kg)

KCl 40 Canola

(mg/kg)

<3 3 to 5 >5 <12 >12

Harden Red & Brown Loams 11% 33% 56% 80% 20%

Horsham Grey & Brown Clay Loams 23% 18% 59% 68% 32%

Maryborough Red & Brown Clay Loams 0% 8% 92% 74% 26%

Cummins Red & Brown Sandy Loams 12% 44% 44% 74% 26%

Moree Gray &Brown Clay/Clay Loams 17% 20% 63%

Dalby Gray &Brown Clay/Clay Loams 15% 23% 62%

Emerald Gray &Brown Clay Loams 27% 19% 54%

Gunnedah Gray &Brown Clay Loams 10% 26% 63%

Soil depth 0-10 – mobility of S in profiles, maybe need a deeper soil

test as routine – when request nitrate, also request sulphate.

Role of organic sulphur – should the budget include mineralised S.

Variable P, generally low S

6% 20%

40% 34%

(<200 PBI & 60 mg/kg)

Pasture soil tests from the Armidale region – IPL Labs,

Low P = Low S, High P = likely low S

Source, Flavel, Guppy & Blair, 2010 World Soil Science Congress.

Old Redgrass. Wallaby Grass, Bluegrass, Kangaroo Grass, over sown with sub, white & red clovers. UNE

http://www.iuss.org/19th%20WCSS/symposium/pdf/1926.pdf

P Recovery 35% 36% 40% 50%

Mar-Jul

Jan-Mar

Dec-Jan

Aug-Dec

Fertilizer responses to P and S

S deficiency in Australia

History of S deficiency in

pastures.

Deficiencies first seen in NSW at

Lockhart.

• Soils naturally low in S.

• Declining soil OM levels

• Reduced use of single super –

clear trend to AP’s

• High demand for S by canola.

• Typically on Red Brown Earths.

• Pale petal colour.

Role of Ammonium Sulphate – Tauhid Khan - PhD

• Is Ammonium sulphate an enhanced S source compared to gypsum?

• Does it enhance P uptake (eg through root zone acidification?)

• What role is there for co-placement of N and S in canola (and wheat).

• Urea/Gypsum compared to Ammonium Sulphate – pots/canola

Days after sowing

4 weeks 6 weeks

N c

on

ten

t (g

/po

t)

0.00

0.02

0.04

0.06

0.08

0.10

0.12

AS

UG

Nil

Biomass

Days after sowing

4 weeks 6 weeks

Bio

ma

ss y

ield

(g

/po

t)

0

2

4

6

8

10

AS

UG

Nil

a

b

c

a

b

a

b

a

b

c

P≤0

.05

P≤0

.05

c

a

N and S treatment

Gra

in y

ield

(t/

ha)

0.0

0.5

1.0

1.5

2.0

2.5

Results: Yield variations in different soil types

Changes of canola grain yield variation in sandy and clay loam soils

Agronomic N efficiency

Sandy soil

AS= 26 kg grain/kg N

UG=14.4 grain/kg N

Clay loam soil

AS= 12 grain/kg N

UG= -2.5 grain/kg N

a

a

a

b

a

bcbcbc

c

P≤0.05

Sandy soil Clay loam soilA

mm

on

ium

su

lph

ate

Ure

a +

Gyp

su

m

Gyp

su

m

Nil

Am

mo

niu

m s

ulp

ha

te

Ure

a +

Gyp

su

m

Gyp

su

m

Nil

Ure

a

2010 Ammonium sulphate responses

• Suggestion that the S response from gypsum was not as good as the S reponse from sulphate in AmS

Nutrient Audit - wheat

• Critical issue is the nutrient contents of produce removed

• Reuter values:

• Evaluate this for wheat

– Took 70 sites from the NVT experiments from 2008 & 2009

– Two cultivars – Yitpi & Gladius

– Analysed for nutrient densities with ICP-OES - Al, B, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, S, Se, Ti and Zn.

– Grain yield and N contents reported through NVT analyses

– Soil test values reported through NVT

Species N P K S Ca Mg

Wheat (11%) * 2.6 3.6 1.4 0.38 1.2

Wheat (0%) * 2.9 4.0 1.6 0.43 1.4

Effect of site, year and cultivar on nutrient content

N P K S

States 0.071 0.509 0.476 0.191

Regions 0.000 0.000 0.014 0.000

Culitvars 0.998 0.017 0.001 0.236

Year (SA only) 0.000 0.864 0.001 0.116

•P values from AnoVar for data sets

•Significant differences among N, P, K and S contents among regions, but

states compensated for these differences.

•So – nutrient budgets between regions can be quite different.

•Significant differences between these two cultivars for grain P and K

offtakes.

•Not possible to investigate the interaction among site/year/cultivar

P, K and S contents -

• S contents do not vary so much

• P and K values do vary significantly

• Bell reported similar results from CQ

P K S

3329 ±671 4606±645 1742±220

Grain P contents

• What drives grain content?

• Tested grain yield

– No

• Tested soil pH

– No

• Tested Soil P content

– No

• Therefore

– To do a reasonable P balance need actual

grain P contents -

Difference between estimates and actuals

• 2010 canola at the Dahlen site

• Measured yield and actual grain P contents

• Reuter grain P content estimate = 5.1 kg P/t of grain

• Actual content varied with P rate significantly

P rate Yield t/ha Estimated

P removal

Actual P

content

Actual P

removal

0 1.44 7.3 4.7 6.8

9 2.76 14.1 6.2 17.1

18 3.07 15.7 6.9 21.2

36 2.89 14.7 7.5 21.6

Wheat grain N:S ratio

S

RESPONSIVE

S

UNRESPONSIVE

Inadequate N

Randell et al. (1981) AJAR 32, 203-212

SE Australian N/S 2009

n=140 (2*70)

Grain Nutrient Levels

(all in mg/kg)

P K S Ca Mg Zn Fe Cu B

International 3600 4000 1700 894 1341 31 59 6 3

CV 53% 20% 24% 61% 33% 41% 62% 61% 71%

Australia 3300 4600 1700 421 1281 23 37 5 2

Australia CV 21% 14% 12% 21% 10% 32% 19% 25% 58%

• International Values taken from IPNI survey of 130 samples from India,

China, Canada, USA, Russia.

• Australian values taken from IPNI survey of 130 samples from NVT

experiments in 2009 from Southeastern Australia. Lowest values in Mallee

and EP samples (19 mg/kg)

Desired range for human health on grains based diet – 35+ mg/kg

Zin

c…es

sential fo

r lif

eWorld Map – Zinc Deficiency

Soils

Humans

Zin

c…es

sential fo

r lif

eExamples of Zinc

DeficiencyRice plants in paddy field

Severe Zn

deficiencyZn treated plot

Pictures: Potash & Phosphate Institute; Int’l Rice Research Institute

Wheat

Response to Zn

Peck et al 2008

Yield Response to 7.5 kg Zn – 2 of 6 sites

Grain Zn Increase on 5 of 6 sites

DTPA Zn test available but difficult to find yield responsive sites

Grain Zinc Content – regional values

State Region Zn (mg/kg)

NSW South East 23.0±2.4

South West 23.5±2.4

SA Lower EP 18.7±2.0

Mid North 25.4±1.8

Murray Mallee 19.2±1.6

South East 24.5±2.2

Upper EP 26.0±1.4

Yorke Penn. 22.2±2.0

Vic Mallee 18.9±1.7

North Central 25.5±3.4

North East 28.8±3.4

Wimmera 27.3±2.2

Total Mean 23.0±7.3

Regions with alkaline soils – not unexpected

Zn/Fe Baseline levels & Target Levels

Wolfgang H PFEIFFER

Zinc and seed vigour

• Zinc seed content versus concentration

• High content important for early vigour

– <500 ng Zn per seed critical value

– Seed size & grain zinc concentration is important

– 15% below critical

• Low Zn level in seed from

various locations

• Consider Zn application for

seed crops – improve vigour

0

200

400

600

800

1000

1200

1400

1600

1800

0 10 20 30 40 50

Zn Content (ng/grain)

New areas for thought

• Post-harvest evaluation of nutrient status in grain

– P removal maps – become P replacement maps

– Zn content of grain – become diagnostic for future Zn responses

• XRF analyses – developed on from ICP – now hand-held XRF –great potential for in-field low cost grain nutrient analyses.

– N:S ratios give direction for potential S responses

• Nutrient balances will become more important as monitoring tools – mining versus pollution.

• A NuGIS exercise for Australia would be interesting but reliable nutrient input data is scarce (fertilizer & manures/feeds).

• Is it time to revisit a collaborative soil test summary – last done as ANRA (1998) and then as a single report in 2003 (Rayment)

0

30

60

90

120

150

180

210

240

270

300

Ha

pe

r s

am

ple

2000s

31

83

26

68

32

262249

Soil sampling and sampling

intensity in selected countries

Years reportedArgentina Australia Brazil China India Russia U.S.

1986 1989 1985 1980-1983 NA 1981-1985 19852008 2009 2008 2005-2009 2008 2001-2005 2005

0

1

2

3

4

5

6

Sam

ple

s p

er

year,

millio

ns 1980s

2000s

0

200

400

600

800

1000

1200

1400

1600

1800H

a p

er

sam

ple

1980s

7232

428

4369NA

Ag holdings/sample

U.S. 0.5

India 22

Estimates based on

best available data

1620

Concluding Comments

• Manage or be managed

• Regulations on nutrient management

– Reef Regulations on sugar industry in the wet tropics

– Use of soluble P fertilizers on the Swan coastal plain.

– Fertilizer management in the Mississippi Basin

– Regulations on N use on particular dairy pastures in New Zealand.

• Right source, right rate, right time, and right place is a simple slogan that integrates a century of science and experience into nutrient stewardship.

• Research backstops the principles of 4Rs with science, but the stakeholders decide what is right.

Better Crops, Better Environment … through Science

http://www.ipni.net

http://anz.ipni.net

Subscribe to Better Crops –

contact me or register online

at: