FAS offers a wide range of agricultural soil testing options for many crops. While our research has focussed on sugarcane for over 60 years, we can now offer soil analysis for tea and coffee, maize, sub-tropical fruit, macadamias, grain crops, gardens, nurseries, golf courses and bowling greens.
Soil analysis is important to optimise production while efficiently managing your resources. Regular soil testing enables the early detection of harmful soil conditions such as acidity and salinity build-up, nutrient imbalances and overloads, and the depletion of organic matter. It is thus a cornerstone of sustainable farming.
What We Offer
|ANALYSES||SA||SADC Countries||Other Countries|
|ROUTINE (SUGARCANE)||Cost Per Sample|
|pH (CaCl2), phosphorus, potassium, calcium, magnesium, sodium, exchangeable acidity (Al+H), total cations, acid saturation, exchangeable sodium, zinc, copper, manganese, sulphur and volume weight. Estimates of clay and organic matter, potential nitrogen volatilisation, nitrogen mineralisation and reserve potassium.
(Fertiliser recommendations for other crops is given on request)
|SUBSOIL||Cost per sample, first depth|
|Routine analysis for each depth. Includes a profile subsoil report with gypsum recommendations where subsoil analysis indicates excessive acidity.||242||268||308|
|Thereafter for each depth, cost per sample|
|SOIL SALINITY AND SODICITY||Cost per element per sample|
|pH; volume weight; exchangeable and saturation extract potassium, calcium, magnesium and sodium; electrical conductivity (EC); saturation %; sodium adsorption ratio (SAR); cation exchange capacity (CEC); salinity and sodicity status and gypsum recommendations.||245||247||284|
|Thereafter for each depth, cost per sample|
|SUPPLEMENTARY||Cost per element per sample|
Sampling Procedures (All Crops)
Topsoil Sampling Procedure
For routine topsoil analyses and fertiliser recommendations, samples should be collected using a Beater auger. Use of this auger ensures that a constant sampling depth is maintained (20 cm for sugarcane; 15 cm for most other crops) and allows for easy collection of a large number of subsamples. If interested please download our soil submission form.
Recommended sampling procedure:
Avoid any obviously different patches of soil, examples are: anthills & old roads, filter cake, lime or fertiliser dumps, etc.
If the field consists of two distinctly different soil types, or only parts of the field have received large amounts of, for example, filter cake, a separate sample should be submitted from each section.
Because a very small amount of soil is analysed in the lab, it is vital that the sample submitted should be a good representation of the ‘average’ conditions across the field. For this reason, at least 30 – 40 subsamples should be collected from each field.
The subsamples should be taken in a zigzag pattern across the field. For ratoon crops, eight interrow subsamples should be collected for every one sample on the row.
Secure a sampling bag onto the top of the Beater auger bit.
Push the bit into the soil as far as it will go; this will ensure the correct depth of sampling. In hard or dry soils, press down on the auger with your foot to ensure that it is fully inserted to the correct depth.
Remove the bit from the ground. Turn the auger upside down and knock the bit with your hand or a stick until all the soil falls into the bag.
Continue to the next position in the field, and repeat the process. The sampling bag will naturally fold over, so that collected soil is not lost after sampling.
Once the correct number of subsamples have been taken, they should be mixed thoroughly in the bag.
Completely fill the FAS sample box with this mixed soil, and discard any soil that is left over in the sampling bag.
Fill in all the necessary details on the sample box, as well as on the soil sample
Subsoil Sampling Procedure
If subsoil acidity problems or any other subsoil nutritional problems are suspected, sampling to further depth should be undertaken before each replanting event.
Follow this recommended sampling procedure before submitting your soil sample:
Soils should be sampled with a Dutch (screw type) auger marked off at 20 cm intervals.
Ideally, samples should be taken to a depth of 80 to 100 cm, in increments of 20 cm (i.e. 0 – 20, 20 – 40, 40 – 60, 60 – 80 and 80 – 100 cm).
Keep the samples from each depth interval in separate bags.
Take three to four subsamples (borings) from random positions across the field.
The subsamples for each depth interval must be placed into the appropriate sampling bag (e.g. all 0 – 20 cm subsamples will be combined into one bag).
Mix the soil in each sample bag thoroughly and transfer into sample boxes.
The sampling depth should be clearly marked on the sample box. Thus there will be up to five sample boxes, each containing a composite sample from a certain soil depth.
Fill in all the necessary details on the sample box, as well as on the soil sample submission form.
Salinity and Sodicity Sampling Procedure
To assess a salinity or sodicity problem in soils, it is recommended that soil samples be taken for laboratory analysis.
This should be done to the recommended depth to ensure that the source and extent of the problem is identified so that an appropriate reclamation strategy can be developed. Please use the correct Sample Submission Form.
Samples should ideally be taken with a Dutch (screw-in) auger, marked off at 30 cm depth increments.
Sample at three depths (0 – 30, 30 – 60 and 60 – 90 cm), taking three to four samples from the field/area being investigated.
In instances where there are patches of suspected salinity/sodicity in a field the suspected patches (usually indicated by poorer crop growth and sometimes salt accumulation on the soil surface) must be sampled separately from areas with better crop growth. Also collect three to four samples at the recommended depths from these areas.
At each sampling site, place the 0 – 30 cm soil into one bag, the 30 – 60 cm sample into another bag and 60 – 90 cm into a third bag. Move on to the next sample site, and place the same depths into these bags.
When three to four sampling sites have been combined, mix the samples thoroughly and submit them to the laboratory. There will thus be three boxes (for the three depths) from the well growing areas and three boxes for the poor growing areas. Remember to fill in the label on the sampling box, as well as the soil salinity sample submission form.
If the area is irrigated, a sample of the irrigation water should be sent to the lab along with the soil samples. See Water Sampling Procedure.
Additional Information for Sugarcane Soil Sampling
- Soil samples can be taken at any time during the year.
- Samples should be taken from every replant field, and ratoon crops should be sampled after every second crop.
- Collect the samples in good time so that they can be analysed and fertiliser purchased and applied before replanting (or ratooning).
- Where fields are to be replanted, soil samples should ideally be taken after the second to last ratoon crop has been harvested.
This allows sufficient time to plan and buy fertiliser and lime.