2012 International Macadamia Symposium – Brisbane, Queensland Australia

Monitoring and manipulating orchard nutrition to

maximise quality and yield:

science, tips, and tools

Integrated Agronomic Solutions

• Laboratory and Analytical Services

• Nutrition Management

• Pest and Disease Management

• Remote Sensing

• Postharvest Quality Control

• Research and Development

• Software and Data Management

• Marketing – B2B and Direct

• Training

AgPro

Hosting of grower data via cloud accounts

Overview

• The basics of nutrition science and management • Integration of nutrition with other agronomic

principles • Trends, nutrient form, manipulation,

Hormone/Nutrient interactions

Why is this relevant to me

• Potential to increase production through greater understanding of macadamia plant nutrition and hormone manipulation/management

• To provide an understanding of and how to

Implement a complete and integrated process to have a real impact on orchard productivity and profit.

Digitise block boundaries to enable you to track performance spatially

Work toward variable rate – NDVI, yield mapping, zonal sampling

• Live soil moisture, EC and temperature monitoring • Quicksoil monitoring of soil solution enables the determination of nutrient

composition

Decline of water

use at 10 cm

Water use

commences at 40 cm

Preferential feeding zones

Mechanisms for nutrient uptake

• Diffusion (osmotic potential) – Nutrient ions move from high to low

concentrations

• Mass flow – Ions move in the soil solution to the plant roots as

a function of transpiration loss of water form the leaves

• Root interception – Suggests roots come into contact with the ions

• Diffusion: potassium, magnesium, calcium and to lesser extent, zinc and iron

• Mass flow: nitrogen, calcium, copper, boron, manganese, magnesium, and sulfur

• Root interception: Calcium, Phosphorous

Mechanisms for nutrient uptake Exchange

Vs

Solution

Nutrient ratios change with depth

This can cause anomalies that, at the surface seem inexplicable

When compared to Sap and quicksoil results, an understanding of nutrient

interactions begins to form

And then a targeted regime can be implemented

Nutrient interactions

Uptake of this

nutrient

Decreases the uptake of these

nutrientsIncreases uptake of these nutrients

NH4+ Mg, Ca, K, Mo Mn, P, S, Cl

NO3- Fe, Zn Ca, Mg, K, Mo

P Cu, Zn Mo

K Ca, Mg Mn (on acid soils)

Ca Mn (on acid soils)

Mg Ca, K, Mo

Fe Cu, Zn

Zn Cu

Cu Zn, Mo

Mn Zn, Ca, Mo

Documented nutrient interactions. (Adapted from Tisdale et al., 1985)

Availability of Macro-nutrients at various pH’s

Micronutrient uptake

Timing of applications

• Matching peak demand of specific elements at each phenological interval (just before) is critical.

• Manipulation of phenological intervals is achieved through the use of each of the 5 plant hormones

• It is essential to match nutrient availability with these application.

• Understanding the partnerships is critical.

Optimal Demand Pathways

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

EV FL FS FF PEH

Mg

Ca

K

P

N

Hormones’ influence on nutrient demand

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

EV FL FS FF PEH

ABA

GA

Au

Cy

Using Sap tests in Macadamias

• sap testing is a snapshot of elements in the sap stream while dried tissue detects the total amount of element in the leaf;

• sap testing, therefore, can detect a temporary shortage caused by a range of factors other than nutrient deficiency in the soil.

• This can be critical if the higher demand is due to heavy nut load and supply is restricted by an imbalance of cations (for instance) or application of an antagonistic hormone.

Using test results to monitor performance of applied product.

or monitor trends to understand optimal demand pathways.

Factors to take into consideration when calculating total elemental requirement

•Balancing requirement from lab result to optimal ratio or level

•Yield goal – nutrient removal

•Sampling depth

•Bulk density

Incorporate your pest and other parameter monitoring into decision making process

As there is strong correlations between nutritional status and susceptibility to pest and disease

How can I implement this on my farm

• invest into understanding what is happening within the orchard (regular pest monitoring, soil, quicksoil, sap and dry tissue testing)

• create an action plan to which performance can be tracked

• implement action plan recording and variations to it

• review results, compare, refine and re implement

Take home message

• Holistic approach to agronomy and management; – soil and tree nutrition are just a cog, but a critical one.

• Importance of MONITORING to target your response and reduce waste • -start a cycle of continuous improvement • Attention to detail • - focus on ppm/ mg/kg and the tons will come • - doing the same thing over and over again but expecting a different result

is the definition of madness. Isolated sequential experimentation • Return on investment for good growers • - 2% of gross production value into technical assistance delvers a 5-10%

return on investment at best and reduces risk of crop failure at worst.

SHARE THE LOAD, DON’T

GO IT ALONE

A FEW SHARP SETS OF EYES ARE

BETTER THAN JUST ONE SET

THERE IS ALWAYS ROOM FOR

IMPROVEMENT SO TURBO CHARGE YOUR ORCHARD

AND START MAXIMISING YOUR

YIELD

Thanks Hortus Technical Services Pty Ltd

Locked Bag 3901, Bundaberg Qld 4670

Unit 1, 336 Goodwood Rd, Bundaberg Qld 4670

Office: +61 7 4132 5000

Mobile: +61 (0) 434 678 228

Email: jack@hortus.net.au

Web: www.hortus.net.au

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