Soil Testing with ARL

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

Why soil test?

  • Establish the status of soil nutrients.
  • More accurately assess fertiliser and lime requirements to maximise your fertiliser dollar.
  • Make better informed management decisions.
  • Allows you to monitor the effectiveness of previous fertiliser applications.
  • Enables monitoring of fertility trends over time.
  • Provides a starting point for looking at sustainability and designing fertiliser programmes.

Soil analysis suites

Standard soil and organic sulphur analysis
Soil nutrient status suitable for pastoral, cropping and horticulture enterprises with sulphate and organic sulphur included. The recommended pastoral soil fertility analysis suite. It is also required if you need an automated pastoral fertiliser recommendation.

Standard soil analysis
Soil nutrient status suitable for cropping and horticulture enterprises including sulphate analysis.

Basic soil analysis
Soil nutrient status suitable horticulture enterprises where plants do not have a high requirement for sulphur.

Extra tests

We also provides a wide range of extra tests designed to meet your needs. Some of the more commonly requested extra tests are:

Anion storage capacity - Also referred to as the phosphate retention test, this measures the ability of the soil to store phosphate and sulphate. Soils with higher anion storage capacities will require larger amounts of fertiliser phosphate and sulphate to raise soil test levels or to overcome deficiencies. Recommended once for each block or paddock.

Reserve Potassium (TBK) - Measures the amount of reserve potassium available in some soils. Recommended every three to five years on sedimentary soils only.

Anaerobic mineralisable nitrogen - Also referred to as the available nitrogen test, this estimates the likely mineralisation of organic nitrogen providing an estimate of soil nitrogen supply. Recommended where land is to be cultivated and cropped.

Organic matter - Organic matter in soil has an important role in the supply of nutrients, improving soil structure, reducing the risk of erosion, increasing the water holding capacity of soils and providing a food source for earthworms and microbes. It generally declines under cropping and increases under pasture.

Recommended once every 4 – 5 years.

Exchangeable aluminium - One reason for poor plant growth in New Zealand on acid soils (those soils where pH< 5.6) can be aluminium toxicity. This test measures the exchangeable aluminium and confirms toxicity problems.

Hot water soluble boron - Provides a measure of available boron in the soil. Recommended where crops have a high boron requirement such as avocados and olives or when changing to crops which are sensitive to boron toxicity.

Trace Element Testing - We offers a number of options for soil trace element testing. We recommend plant tissue testing in conjunction with animal liver/blood tests for determining trace element deficiencies in pasture.

How do I sample for soil analysis?

Select sites to take soil samples from. The samples should be representative of the whole area taken in a transect (line) or grid pattern and should be taken in a way which can be repeated from year to year. Painting fence posts, use of GPS or placing pegs under fences can permanently identify sampling lines.

Make sure the core is taken at the appropriate depth. Core depth should be 7.5cm for pastoral soils and 15cm for cropping and horticultural soils. Soil augers are specifically designed for this purpose, alternatively a clean spade can be used but it is essential to maintain core width i.e. not sample in a wedge shape and that the core is sampled to the correct depth. Soil augers can be ordered through ARL (0800 100 668), or rented from your local Ravensdown store.

  • Take a minimum of 20 individual cores at 10 metre intervals.
  • Securely close the sample bags and label them clearly.
  • Do not sample within three months of applying fertiliser or lime, as residual granules may distort your results.

Fill in the soil 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 the refrigerator (any delay exposes the sample to excess heat and moisture and can affect the analysis).

For Crop specific information see our Soil sampling guide below.

Pastoral fertiliser recommendation

If you require an fertiliser recommendation (applicable to conventional dairy, sheep, beef and deer pastoral farming systems) to accompany your soil test results, simply supply your farm information on the soil submission form. Our Technically trained team will follow up with a recommendation to suit your needs.

Note: You must select the Standard Soil with Organic Sulphur test for us to complete this recommendation.

How many samples and how often?

We recommends sampling as much of your farm as possible to assist in long term planning and providing for the overall sustainability of your operation. It’s a small investment to add science to your land management practices.

Maximum advantage from soil testing is best achieved by repeated testing on a regular and planned basis, rather than relying on a “snap shot” in time. For most situations an annual soil test, coupled with plant tissue testing during the growing season is recommended.

Soil testing documentation

Soil testing price list
Soil testing sampling guide
Soil testing submission form