Plant Testing with ARL

Plant analysis indicates whether your plants have the right amount and balance of nutrients.

We have a range of plant analysis options that will provide information essential to measuring and managing the health and productivity of your pasture, crops and animals.

Why plant test?

As well as indicating whether your plants have the right amount and balance of nutrients for optimal production, plant testing is also a useful tool for:

  • Providing a guide on the critical nutrient concentrations required for maximum production and optimal crop quality for individual crop types at particular stages of growth
  • Determine trace element nutritional status and fertiliser requirements of annual and perennial crops
  • Determining the mineral concentrations of animal feed, particularly herbage, helping ensure maximum animal production
  • Diagnosis of plant health problems, including trace element deficiencies and nutrient toxicities
  • Monitoring the effectiveness of your fertiliser programme

With all testing services, we provide the most current crop by crop interpretative information available to turn your test results into information that can be readily used in farm management decisions.

Find out more about how plant testing can help you 

Getting the measure of your crops

How do I sample for plant analysis?

Because the critical nutrient concentrations for different crop types are specific to parts of the plant and stage of growth, it is important to adhere to the plant sampling guide. Failure to do so may lead to misleading results and advice.

Ensure your hands are clean or if using shears or scissors ensure these are also clean, as rust or soil can contaminate samples. Recent applications of fertiliser, foliar feeds and certain pesticides may affect the results.

When sampling take plant tissue from a representative number of different sampling sites or plants - more than 15 is desirable.

For pasture samples walk along your chosen transects (lines) taking a handful of pasture every 10-20 metres. Take the sample at animal grazing height.

Each sample should be made up of 15 or more handfuls of pasture. Provide enough sample by filling the sample bag provided (equivalent to 2 litres for a mixed pasture or ½ litre for a clover only sample).

Pasture samples are normally taken during periods of active growth (such as during spring or autumn flush).

For arable and horticultural crops refer to our plant sampling guide. In the case of fruit trees and vines it is recommended to mark the trees or vines that you have sampled from, so that you can return to these same trees for future sampling.

Avoid inclusion of soil in plant samples where possible because contamination from soil can compromise test results.

Squeeze the air out of the sample bag before sealing it tightly.

Clearly identify the sample and the block the sample came from on the bag form.

Fill in the submission form and put the samples plus the submission form in the pre-paid courier bag and send them to ARL immediately or store in a refrigerator (any delay exposes the sample to excess heat and moisture and can affect the analysis).

What if I’m trying to diagnose a plant health problem?

If testing because a plant or crop is poorly performing, it is a good idea to take two representative samples, one from each of the good and poor performing areas, and send for analysis.

Plant analysis suites

Basic Plant Analysis

Analysis of the major nutrients and trace elements required for arable and horticultural crops.

(N, P, K, S, Ca, Mg, Na, Fe, Mn, Cu, Zn, B)

Standard Pasture Analysis

Analysis of the major nutrients and trace elements required for plant growth and animal health.

(Basic Plant Analysis + Co, Se, Mo)

Clover / Brassica / Legume Analysis

Analysis of the major nutrients and trace elements required for clover, brassica or legume plant growth.

(Basic Plant Analysis + Mo)

Comprehensive Pasture Analysis

Analysis of the major nutrients and trace elements required for plant growth and animal health. The sample is split into two with a Standard Pasture Analysis carried out on half of the sample and a Clover Analysis on the clover portion of the other half of the sample. ARL will separate the clover from the sample for the Clover Analysis. This ensures the complete picture for optimum mixed pasture performance.

(Standard Pasture Analysis on whole sample and Clover Analysis on clover only)

Plant Petiole Analysis

For grapes at flowering and potatoes during early season development (50 days after emergence) Petiole Analysis is recommended. Refer to the plant sampling guide for the appropriate sampling time or growth stage and the quantity of plant petioles to collect.

(Basic Plant Analysis + NO3-N)

Potato Petiole Analysis

Test suite tailored for potato.

(P, K, Mg, NO3-N)

Specific Crop Package

Specific crop packages such as analysis of grape berry juice or whole fruit analysis of apple and kiwifruit.

Guide to Interpreting Herbage Test Results for Animal Health

Micro nutrients Macro nutrients


Additional tests available

ARL provides a wide range of extra tests designed to meet your needs. Refer to the ARL price list for the full range of tests available. For specific crops refer to our plant sampling guide  plant sampling guide for recommended extra tests. Some of the more commonly requested extra tests are:

Nitrate – levels in pasture and crops under certain conditions can accumulate to toxic levels which may lead to stock death. ARL offers urgent nitrate testing for diagnosing at risk crops.

Iodine - essential for animal growth and development. Plant tissue iodine testing is useful in the same way that other trace element plant testing is used.

Chloride - This test should be used on plants which have a higher chloride requirement such as Kiwifruit or when chloride levels can indicate plant health problems such as in avocados

Plant testing documentation

Feed and plant testing price list
Feed and plant testing sampling guide
Feed and plant testing submission form

Testing Brochure