Soil Testing with ARL
The first step in designing a fertiliser programme is to test your soil.
Why soil test?
Soil testing helps you establish the nutrient status i.e. “the reservoir” of your soil. It also means you are able to:
- More accurately assess fertiliser and lime requirements and maximise your fertiliser dollar
- Make better informed management decisions
- Monitor the effectiveness of previous fertiliser applications
- Keep track of fertility trends over time
- Establish a starting point for looking at sustainability and designing fertiliser programmes
Getting the best soil sample
The greater the variation in a sample area the more difficult it is to manage and fertilise it correctly. The key to taking a representative sample is to choose sample areas that have a similar soil type, fertiliser history, productivity, topography (slope) and land use. Sample numbers should increase with greater variation in these factors.
You will get the most value from your sample when the area it represents varies the least.
Below is a step by step guide. For more detailed crop specific information refer to the Soil Testing Sampling Guide.
How do I sample for soil analysis?
The greater the variation in a sample area the more difficult it is to manage and fertilise it correctly. The key to taking a representative sample is to choose sample areas that have a similar soil type, fertiliser history, productivity, topography (slope) and land use. Sample numbers should increase with greater variation in these factors.
You will get the most value from your sample when the area it represents varies the least.
Step 1
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. Avoid areas that are not typical of the block/paddock that you are looking to sample from, such as, gateways, troughs, fence lines, unusually high or low fertility “spots” and manure or waste spots.
Step 2
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. A soil auger can be borrowed or purchased from ARL or your local Ravensdown store. 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. Take a minimum of 20 individual cores at 10m intervals.
Step 3
These 20 cores make up one sample and can be placed in one ARL sample bag.
Step 4
Securely close the sample bags and label them clearly.
Step 5
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).
Step 6
From the day we receive your samples it usually takes 4-10 days to get your results to you, depending on the soil type and test requests.
Samples can be sent or dropped off to the lab:
9 John Morten Place,
Rolleston 7614.
How many soil samples and how often?
We recommend 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.
You will get the most value from your sample when the area it represents varies the least.
Soil Testing Suites
Soil quality underpins agronomic decision-making and long-term crop performance. Our soil testing services provide comprehensive data on nutrient availability, soil chemistry, and fertility status, giving you the insights needed to tailor nutrient management strategies with precision. By quantifying key soil parameters, you can make informed, evidence-based recommendations that optimise productivity and sustainability outcomes for growers.
View our Soil Testing Suites.
