Technical Services
Soil Analysis
Soil analysis is an essential part of developing a comprehensive fertilizer strategy for the coming season. This service involves gathering critical information on nutrient levels and other key soil traits.
At Summit, we offer a complete soil analysis service. Soil analysis is an essential part of developing a comprehensive fertilizer strategy for the coming season. It involves gathering critical information on nutrient levels and also other key soil traits such as organic carbon, electrical conductivity, pH and the soil’s phosphorus buffering index (PBI).
During a soil analysis, your local Summit Area Manager will take soil samples to get a deep understanding of your farm’s nutrient requirements. Drawing on local information and backed by our science, they will meet with you regularly to develop a long term fertilizer strategy designed to build the value of your farm.
Benefits of a Summit Soil Analysis
- Independent laboratory testing
- Rapid turnaround times
- Wide range of nutrients measured
- Practical recommendations based on results
- Soil test reports available to view and download online via SummitConnect
Nutrients Analysed
Learn more about the common soil nutrient analysis tests that we do, and how to interpret test results by taking a look at our quick guide.
Soil Analysis
View Soil Sampling Guide
Nutrient
Symbol
Units Used
Adequate Range Expected
Comments
Phosphorus
P
ppm (mg/kg)
15 - 45
Dependent on crop/pasture type and soil type.
Potassium
K
ppm (mg/kg)
40 - 120
Lupins and Canola are less sensitive to K deficiency. Clover and Medic require higher soil levels.
Sulphur
S
ppm (mg/kg)
5 - 15
Dependent on soil type.
Nitrate
NO3
ppm (mg/kg)
up to 30
Very mobile in the soil. May be lost to leaching.
Ammonium
NH4
ppm (mg/kg)
up to 20
Stable in the soil as it is a cation, but converts to Nitrate readily.
Copper
Cu
ppm (mg/kg)
> 0.3
Soil tests for Copper are a guide only.
Zinc
Zn
ppm (mg/kg)
0.12-0.5
Dependent on soil pH. The more alkaline the soil (higher pH) the higher the soil Zinc level needs to be.
Organic Carbon
O.C.
%
1.0 - 3.0
Dependent on soil type and rainfall.
Electrical Conductivity
EC (1:5)
dS/m
< 0.25
A measure of 'salinity'. Highly dependent on soil type with heavier soils having some buffering capability, but generally EC (1:5) values <0.2 are non-saline and >0.7 is of concern and possibly accumulating salt.
A variable conversion factor can be applied so values will fit one scale across all soil types. This is called 'estimated EC' or ECe. In this case ECe threshold of >8 represents highly saline soil.
A variable conversion factor can be applied so values will fit one scale across all soil types. This is called 'estimated EC' or ECe. In this case ECe threshold of >8 represents highly saline soil.
pH
(CaCl2)
>5.0
Aluminium
Al
ppm (mg/kg)
<5.0
As pH declines (becomes more acidic) aluminium can increase in soil solution. Aluminium is toxic to roots. When roots don't grow, plants cannot explore the soil to access nutrients and soil moisture. Levels above 5 mg/kg strongly impact wheat. Other crops such as barley are more sensitive (Read the article on soil pH here)
PBI
PBI (Phosphorus Buffering Index) is a function of soil type. Generally where soil particles contain more iron, aluminium and calcium such as forest gravels, plus some soils with considerable clay and organic matter, the PBI will be higher and decrease plant-available P (See article)
Nutrient
Symbol
Units Used
Nitrogen
N
%
Phosphorus
P
%
Potassium
K
%
Sulphur
%
Calcium
Ca
%
Magnesium
Mg
%
Copper
Cu
ppm
Zinc
ppm
Manganese
ppm
Boron
B
ppm
Sodium
Na
ppm
Iron
Fe
ppm
Nitrate
ppm
Chloride
Cl
%
Options
Molybdenum
Mo
ppm
Other nutrients can be analysed on request, including Cation Exchange Capacity (CEC) which involves analysing calcium, magnesium and sodium in conjunction with a potassium test to calculate CEC.
