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).

Summit Fertilizers offers a complete soil analysis service, your local Area Manager will be on hand to take samples and provide impartial advice based on the results.    

Key Benefits

  • Independent laboratory
  • Rapid turnround times
  • Wide range of nutrients measured
  • Practical recommendations by Area Manager based on results
  • View and download your soil test reports on the SummitConnect online customer portal

Nutrients Analysed

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(salt) dS/m <0.02 Levels <0.2 are generally considered negligible. Levels >0.8 can be said to be accumulating salt, and should be investigated further.
pH (CaCl2)   >5.0 Economic responses to applying lime to increase pH above 5.0 are doubtful. If subsoil pH is low, it may be necessary to increase topsoil pH >5.5 (CaCl2)
Aluminium (CaCl2)   5.0 As pH declines (becomes more acidic) Aluminium levels can increase in some soil types. High Aluminium levels will affect root growth reducing their ability to explore large volumes of soil and therefore their access to nutrients and soil moisture. (Read the article on soil pH here)
PBI       PBI is a function of soil type. Generally as a soil contains more iron, clay and organic matter, the higher the PBI.
(See article)

Other nutrients can be analyzed on request. Most commonly now farmers are asking for Cation Exchange Capacity (CEC) which involves analyzing for calcium, magnesium and sodium in conjunction with the potassium test to calculate CEC.

Soil Sampling Guide

For information on accurate soil sampling, visit this page

Phosphorus Buffering Index

Soil Sampling Vineyards