Variable Rate Solutions

We can help you reduce input costs and improve yields, boosting both the profitability and environmental outcomes of your farm.


for better outcomes.

Variable rate technology (VRT) is delivering significant advancements for the Agricultural industry. By reducing overall inputs and placing them where they’re needed most, VRT assists the profitability of farms while simultaneously reducing greenhouse gas emissions for better environmental outcomes and carbon credit opportunities.

Precision Ag is Australia’s largest independent provider of soil sampling services that help agronomists and farmers identify and address soil constraints.

We use a range of methods to uncover these constraints including grid soil sampling, EM38 & Gamma radiometric surveys and strategic deep soil sampling.

We can then set jointly set targets and generate prescription maps for your requirements, and in any controller format, using our proprietary platform, Soli.

Typical Variable rate applications


unlock your soil’s potential

Develop A Soil
Management Plan
We will meet you and/or your agronomist/farm advisor to identify soil issues and constraints. We will then assess, prioritise and develop a Soil Management Plan to suit your business and budget
Select Sampling
We choose the right tool for the right job.

We decide on grid or strategic soil sampling. We may create management zones using EM38 & Gamma technologies.
Accurate results are important and we use a certified NATA laboratory.
Produce VR Application maps
Our industry leading platform – Soli – will process the soil laboratory results at speed, and produce clear, actionable insights including spatial results.
Generate “Plug and Play” Prescription Files
With your targets set, our platform – Soli – can generate plug and play files for any farm controller so your prescription file will work seamlessly.

We can even load it onto your controller remotely.
Review annually
We recommend reviewing your results and soil management plan annually to ensure you maximise the benefits of your program.

our most common variable rate solutions


Phosphorus is an essential macronutrient for plant growth. Phosphorus available for crop growth is a function of both the Colwell P and the Phosphorus Buffering Index (PBI) of the soil.

The higher a soils PBI the higher the critical Colwell P for crop/pasture production and the more P fertiliser that is required to increase plant available P.

Soil Constraint
Colwell Phosphorus Map

Variation: High

Range: 5.0 – 74.0 mg/kg

VR-MAP Application Map

Target: 30.0mg/kg

Rate: 123kg/ha

Total MAP: 28.1 Tonnes


Soil acidity can significantly reduce crop productivity and soil health. While the critical pH levels vary by crop type, research has shown that as pH drops below 5.2 grain yield can start to decline. As the pH drops below 4.5 aluminium toxicity may also become an issue affecting crop production.

Soil Constraint
pH Map

Variation: High

Range: 4.3-7.8 pH units

Lime Application Map

Target: 5.8pH

Total Lime: 375 T

Target: 5.8pH


Exchangeable Sodium Percentage (ESP) is a measure of soil sodicity. Because it enhances the swelling and dispersion of clay particles, high sodicity can lead to the deterioration of the soils physical condition. Soils with an ESP greater than 6% are considered sodic.

Soil Constraint
Exchangeable Sodium Map

Variation: High

Range: 2.29 – 19.48%

VR-Gypsum Application Map

Rate: 1.96t/ha

Total Gypsum: 450 Tonnes


Potassium (K) is an essential macronutrient for crop growth, with large quantities taken up from the soil during the growing season and potentially exported in produce. Critical K values for wheat range from 35-70 mg/kg depending on soil type and pasture range from 125-160 mg/kg.

Soil Constraint
Soil Potassium Map

Variation: High

Range: 125-160 mg/kg

Potash Map

Rate: 12 kg/ha

Total potash: 2 tonnes


Using EM38 survey (an accurate and established method for mapping soil types), we can measure soil apparent electrical conductivity (ECa), which is influenced by soil texture (clay type and content), soil moisture, and salinity.

An EM38 survey is considered reliable for VR-N due to the strong relationship between soil texture and drivers of N availability and crop uptake. For example, heavier soils will generally provide greater N mineralisation and have lower
losses of N to leaching. Soil texture also affects plant available water, which in water-limited environments will strongly affect crop N requirements.

Once the EM38 survey is completed, we can use strategic sampling to determine current N reserves and determine fertiliser requirements for the zone.

Soil Constraint
EM38 Survey Data

Variation: Medium

Blue = Heavy; Green = Medium; Red = Light

VR-Urea Application Map

Rate: 110 kg/ha

Blue = 50; Yellow = 100; Red = 150kg/ha

Get in touch.

1800 773 247 email Enquire