Workshop Wrap : A Recipe for Better Soil – DIY Fertiliser

This post is a presentation summary with recipes included, of a recent workshop held by the Lower Blackwood LCDC in which presenter Mark Tupman from Productive Ecology demonstrated how to create your own biologically active liquid fertiliser using a carefully balanced blend of ingredients designed to support soil health and plant growth.

The presentation focused on improving nutrient use efficiency (NUE) by understanding how nutrients behave in the soil-plant system and applying fertilisers strategically rather than routinely. It emphasises that good nutrient management increases productivity, reduces costs and minimises environmental losses.

Key Points:

1. Follow the 4Rs of Fertiliser Application

The foundation of good nutrient management is applying the:

• Right Type of fertiliser
• Right Rate
• Right Time
• Right Place

These four principles help maximise nutrient uptake while reducing waste and environmental impacts.

2. Nutrient Use Efficiency is Often Low

Plants only recover a proportion of the nutrients applied. Examples include:

• Nitrogen: 30–50%
• Phosphorus: 15–20%
• Potassium: 50–60%
• Sulphur: 8–12%
• Most micronutrients: 1–5%

This highlights why improving nutrient efficiency is so important.

3. Nutrient Efficiency Depends on Context

Successful fertiliser programs depend on more than simply applying nutrients. Key factors include:

• Soil physical, chemical and biological properties
• Plant species, variety, age and root characteristics
• Climate (rainfall, temperature and sunlight)

The same fertiliser can perform very differently under different conditions.

4. Test, Don’t Guess

The presentation strongly promotes making fertiliser decisions based on testing rather than assumptions. Examples include:

• Soil testing
• Plant tissue testing
• Understanding Phosphorus Buffering Index (PBI) to determine phosphorus requirements

Testing allows fertiliser rates to match actual crop needs.

5. Understand Nutrient Mobility

Different nutrients move through the soil differently.

Very mobile (high leaching risk):

• Nitrate nitrogen
• Sulphur (sulphate)
• Boron

Moderately mobile:

• Ammonium
• Potassium
• Calcium
• Magnesium
• Molybdenum

Relatively immobile:

• Phosphorus
• Copper
• Iron
• Manganese
• Zinc

Knowing nutrient mobility helps determine the best placement and timing of applications.

6. Consider Fertiliser Properties

The presentation discusses:

• Solubility of different fertiliser products
• Salt index of fertilisers
• Suitability for foliar versus soil application

These characteristics influence how quickly nutrients become available and the potential for crop damage or nutrient losses.

7. Nutrient Uptake Depends on More Than Supply

Efficient nutrient use also requires attention to:

• Crop nutrient demand
• Nutrient form
• Enzyme cofactors
• Energy availability within the plant
• Balanced nutrition

Providing one nutrient alone may not improve plant growth if other essential nutrients are limiting.

8. Nitrogen Form Matters

The presentation explains that:

• Converting nitrate into proteins requires significant plant energy.
• Different nitrogen forms influence how much energy the plant must use.
• Nutrients such as sulphur, molybdenum and nickel are essential components of enzymes involved in nitrogen metabolism.
• Sulphur is also needed to produce important amino acids like methionine and cysteine.

Balanced nutrition supports more efficient protein synthesis and plant growth.

9. Continuous Improvement is Essential

Good nutrient management is an ongoing cycle:

1. Collect data
2. Monitor and test
3. Inform decisions
4. Apply management changes
5. Measure outcomes
6. Repeat

This adaptive approach allows nutrient programs to improve over time based on evidence rather than routine practice

Overall Marks presentation emphasises that efficient fertiliser use is about managing the entire soil–plant system, not simply applying more nutrients. By following the 4Rs, understanding soil and plant interactions, using soil and tissue testing, recognising nutrient mobility, maintaining balanced nutrition, and continually monitoring results, growers can improve productivity, reduce input costs and minimise environmental impacts.

See the full presentation and recipes below:

For more on this topic head to our content hub: Targeting Plant Nutrition

This event formed part of the Lower Blackwood LCDC’s Regenerative Agriculture in Practice Program (RAPP) 2026. RAPP is supported through funding from the Shire of Augusta Margaret River’s Environmental Management Fund. This event also forms part of a collaborative project with RegenWA called ‘Make Your Hectare Count’, which is supported by funding from the Western Australian Government’s State NRM Program. Additional support has been provided through RegenWA’s Accelerating Regenerative Agriculture Adoption Project, and the WA Landcare Network, which is funded by State NRM, Lotterywest and the National Landcare Network.