Advances in nutrition management of radiataGraham Coker, Peter Clinton

Research Aim 1.2 Enhancing the productivity of older stands

RA GOALS• Identify and screen new treatment options• Better understand which nutrients are limiting crop growth and why (process

and mechanisms). • Establish field trials to investigate wood quality and environmental effects

TODAYS PRESENTATION• Overview of the approaches taken• Describe some of the results• Summarise advances in our understanding

OUTCOMES by 2019• Better understanding of the role of nutrients in wood formation• A new understanding of the role of nutrients in signalling stress• Better methods for predicting responses to mid-rotation interventions and

updated DSS response functions

Overview – mechanisms for change

Urea 16

Urea 20 kg/ha

DAP 20 kg/ha

Phos-Pot 4 L/ha

PerkSupa 5 L/ha

Phos-Pot 10

Urea 435

2

4

6

8

10

12

14

16

18

0 20 40 60 80 100 120 140

% P

rodu

ctiv

ity g

ain

over

the

cont

rol

Cost ($) of product per hectare

http://grochem.co.nz/Portals%5C537%5Clabels/Phospot_20L.pdfhttp://www.keyindustries.co.nz/product/Perk+Supa-1018.htmx

Control = untreated above ground biomass of GF19’s

GA3 20g/ha

Advance 1 – Identified new treatment options, screening trials in 2016

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4

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28

0 20 40 60 80 100 120 140

(%) H

eigh

t gai

n ov

er c

ontr

ol

Cost ($) of product per hectare

GA4/7 6.6g/ha

PerkSupa 2 L/haUrea 16 PerkSupa 5L/ha

Phos-Pot 4

Phos-Pot 2Urea 20

Advance 2 – Investigated genotype responses, interim results, 2017

Amino-max 10L/ha

Control = untreated height of 12 genotypes, each having 18 reps, Trts :. 216 individual plants

Trials to date show

1. Foliar applications of nitrogen and phosphorus are more cost efficient compared with conventional operations, based on results to date.

These treatment options will help growers better match crop demands with supply at all stages of stand development, where intervention is justified.

2. The relationship between productivity and foliar applied N is consistent across the rates applied.

Every dollar spent on N provided a 2% gain in productivity.

Bown et al 2007: Tree Physiology, 27, 335-

100

61.7

13.2 9.4 7.0 6.82.0 1.2 0.30 0.28 0.08 0.04

N K Ca P S Mg Al Mn Zn Fe B Cu

% o

f fol

iage

nut

rient

s by

mas

s in

rela

tion

to N

Eg. 1.42% N * (61.7/100) = 0.876 % K

Advance 3 – Improved understanding of foliage nutrient ratios

Advance 4 – Identified Mehlich 3 soil extraction analysis method, suitable for forestry, (its widely used in agriculture and a cost effective indicator of soil chemistry)

0.1

1

10

100

1000

10000

Al Fe Ca Mg K Na Mn P Zn Cu B

Nut

rient

s (m

g/kg

= p

pm) –

log

scal

e

Berwick Kinleith Kaingaroa Waimea Tairua

Advance 5 – Identified and recommend soil nutrient targets to better identify limits on growth, an example based on the mid-rotation trials

50000

50002000

600280 250 225

5025 22 22

63

0.7

0.1

1

10

100

1000

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100000

C N Ca Al P K Mg Fe Mn Na S Zn Cu B

Nut

rient

s (m

g/kg

= p

pm)

Average Target

McKibben W L, 2012: The Art of Balancing Soil Nutrients – a practical guide tointerpreting soil tests. Acres USA, 240 pp

Advance 6 – Improved understanding of the influence of soil pH

• pH is influencing soil phosphorous availability• Soil microbial activity decreases with acidity • Cations buffer rapid pH change

Stevenson and Cole (1990)

Overview – mechanisms for change

Advance 7 – Improved understanding of sites that are unlikely to respond to granular P fertiliser

• Veritec soils database, sample size 432

N addition

Lime

Al & Fe inhibition

Mn toxicity

Num

ber o

f site

s

How we are taking advantage of these advances

1. Focusing on foliage N & P, because its relevant to all sites across NZ

2. Informing GxE discussion/understanding3. Improved understanding of nutrient limitations at sites

4. More accessible soils information for management considerations

5. Better target applications and sites

6. Establishing new trials to test our hypotheses

In summary• Foliage applications of N & P are potentially more efficient

than current practices

• Check foliage nutrition in relation to foliar N levels

• Use Mehlich 3 as part of your future soils analyses

• Protect soil pH, because it influences phosphorus availability and lots more

http://research.nzfoa.org.nzwww.scionresearch.com

www.gcff.nz

Graham Coker, Project Leadergraham.coker@scionresearch.com

29/03/2017

Thanks to the team: David Henley, Rodrigo Osorio, Tony Evanson, Stephen Pearce, Max Novoselov, Alex Manig, Jessica Shailer,

Jianming Xue, Loretta Garrett, Bernadette Nanayakkara, Stefan Gous, Kaye Eason, Forest Industry collaborators and others

Benefits of foliar applications

• Target the crop rather than the soil processes

Mobile N pool (NO3)

1%

Organic N -locked in

dead fauna and fauna

(amino acids & protiens)

96%

Potentially available N pool (NH4)

3%

• Add small quantities of fertiliser relative to the soil nutrient pools for growth gains.

Benefits of foliar applications

Amines to Nitrates

Nitrates to amines

Amines to amino acids

Amino acids to proteinGranular Urea

Foliar applied Urea

foliar applied N is 10-12% more efficient than granular applied Urea because less plant energy is required

Granular Urea made mobile

Microbial conversion

• Nutrients are in a formulation closer to what the plant needs.