Soil health: The foundation of every productive farm

Soil is the primary production asset in agriculture. Its physical structure, chemical composition, and biological activity determine how effectively crops and pastures access water, nutrients, and oxygen, and how resilient farming systems are to climatic variability.

Australian soils are old, highly weathered, and often low in organic matter, making them inherently vulnerable to decline under intensive cropping and grazing. Across many agricultural regions, degradation is expressed as acidification, salinity, erosion, compaction, and nutrient imbalance.

Loss of organic matter is a central challenge. Over the past 250 years, Australia is estimated to have experienced one of the largest cumulative declines in soil organic carbon globally, reducing the ability of soils to store water, cycle nutrients, and maintain stable structure.

Maintaining and restoring soil function has therefore become a priority across Australian agriculture. Producers, researchers, and agtech developers are increasingly focused on improving soil health as a pathway to stronger productivity, greater input efficiency, and long-term land resilience.

What soil health really means

Soil health refers to the soil’s capacity to function as a living system that supports plant growth, regulates water, cycles nutrients, and maintains biological activity over time. Soil health reflects the interaction between three core components:

• Physical condition, including structure, aggregation, and water movement
• Chemical condition, including nutrient balance, pH, salinity
• Biological condition, including organic matter, microbial activity, and soil organisms.

When these components are in balance, soil health improves, resulting in stronger root development, improved infiltration and water use, more efficient nutrient cycling, and greater resistance to compaction and erosion. These characteristics directly influence yield stability, input efficiency, and long-term soil productivity.

Australian research programs are increasingly shifting from measuring individual soil properties to assessing soil function at a systems level. Work such as Dairy Australia’s Soil Health Framework aims to provide consistent and standardised approach for measuring, monitoring, managing, and reporting soil health in Australian agricultural production systems.

Soil health vs soil fertility

Soil fertility describes the supply of plant-available nutrients. Soil health, on the other hand, is the continued capacity of soil to function as a living system, sustaining productivity, maintaining air and water quality, and promoting the health of plants, animals, and people.

Soils can be fertile but not healthy, for example when affected by physical challenges like compaction, erosion, and surface sealing, or biological conditions like low organic matter. These constraints limit root depth, reduce infiltration, and restrict nutrient uptake even when synthetic fertilisers are applied. 

Separating fertility from soil health allows agronomic decisions to address the underlying limitations to production rather than just correcting the symptoms.

Why soil health matters - for farms and the environment 

Soil health underpins both farm productivity and key environmental outcomes, but the mechanisms and timeframes differ. Some soil functions directly improve crop performance and input efficiency, while others contribute to resilience, ecosystem services, and long-term sustainability. Understanding this distinction helps guide practical management decisions.

Production benefits

Yield stability
Soils with stable aggregates, low compaction, and good water holding capacity allow roots to explore a greater soil volume and access stored moisture and nutrients. This reduces the likelihood of stress during key growth periods, improving yield reliability under variable rainfall and temperature conditions.

Water use efficiency
Soils with good infiltration retain more rainfall and irrigation water. Efficient water storage increases the amount available to crops and pastures, and reduces vulnerability to moisture stress.

Nutrient cycling and efficiency
Soil health affects how nutrients are stored, released, and retained within the root zone. Higher organic matter, active biology, and stable structure allow a greater share of crop demand to be supplied from soil reserves, improving fertiliser efficiency, reducing losses, and lowering the amount of applied nutrients required to maintain production.

Root development and exploration
Soils with minimal compaction, stable aggregation, and adequate aeration support deeper and more extensive root systems. Deeper roots increase access to water and nutrients, improve plant resilience, and enhance overall productivity.

Operational reliability
Soil condition affects how reliably paddocks can be worked. Soils with stable structure and adequate drainage are less susceptible to compaction, rutting, and surface sealing, improving trafficability and allowing key farm operations to be completed within narrow seasonal windows.

Environmental and long-term system benefits

Reduced erosion risk
Soil structure, ground cover, and organic matter levels strongly influence erosion risk. Well-aggregated soils with stable surface cover are less vulnerable to wind and water erosion, protecting topsoil, maintaining nutrient reserves, and preserving long-term land productivity.

Improved water quality
Soils with good structure and infiltration reduce runoff by cycling water through the soil profile. This lowers the transport of sediment, nutrients, and chemicals to waterways, improving downstream water quality and reducing catchment-level impacts.

Carbon retention and sequestration
Soil organic carbon is central to soil function, influencing aggregation, water holding capacity, and nutrient supply. Maintaining or increasing carbon levels supports long-term soil stability and contributes to climate mitigation through carbon storage in agricultural landscapes.

Enhanced biological diversity
Soil health affects the diversity and activity of microbial and soil faunal communities. These biological systems support residue breakdown, nutrient cycling, and disease suppression, contributing to more stable and resilient production systems over time.

Long-term land productivity
Maintaining soil structure, organic matter, and biological function preserves the productive capacity of the land. These factors determine how well soils withstand drought, heavy rainfall, and intensive use over time, and are critical for sustaining agricultural production under changing climatic conditions.

How to measure soil health effectively

There is no single test that defines soil health, because no individual soil property (or group of properties) can universally indicate soil performance across all farming systems, ecosystems, geographies, seasons, and markets. Effective assessment requires a combination of indicators to understand how well the soil is functioning.

Physical indicators:

• Compaction and bulk density
• Aggregate stability
• Infiltration rate
• Root penetration depth
• Surface crusting or sealing.

Field observations, infiltration tests, and penetrometer measurements can provide useful information alongside laboratory analysis.

Chemical indicators:

• pH
• Macronutrient and micronutrient balance
• Salinity
• Soil organic carbon
• Cation exchange capacity.

Regular soil testing allows changes to be tracked over time and helps guide fertiliser and amendment decisions.

Biological indicators:

• Soil organic matter levels
• Microbial biomass or activity
• Earthworms and visible soil fauna
• Residue breakdown rates
• Root health and mycorrhizal activity.

Biological testing is becoming more accessible as new monitoring technologies are developed, including soil microbial DNA testing.

The 5 principles of soil health explained

Left to nature, soil takes centuries to grow, through processes such as rock weathering, organic matter accumulation, and the activity of plants and microorganisms. But deliberate agricultural management can also ‘grow’ soil, enhancing fertility and function to unlock greater productivity. 

Research across a wide range of soil types and climates has identified a set of practices that support this thesis. Commonly described as the five principles of soil health, they provide a practical framework for maintaining and growing soil condition over time.

Keep soil covered

Maintaining ground cover protects the soil surface from erosion, reduces evaporation, and moderates soil temperature. Practices include stubble retention, cover crops, and maintaining pasture cover where possible.

Minimise soil disturbance

Frequent cultivation breaks down aggregates, increases oxidation of organic matter, and disrupts soil biology. Reduced tillage and limiting unnecessary disturbance helps preserve soil structure and biological activity.

Maximise plant diversity

Different plant species contribute different root structures, residues, and biological interactions. Crop rotations, mixed pastures, and multi-species cover crops can improve soil structure, nutrient cycling, and system resilience.

Maintain living roots

Living roots provide a continuous energy source for soil microbes and help maintain aggregation. Keeping plants growing for as much of the year as possible supports biological activity and improves soil stability.

Integrate livestock where appropriate

Managed grazing can stimulate plant growth, recycle nutrients, and improve soil structure. Livestock integration is not suited to every farm or system, but it can be an effective tool for improving soil health where it fits the production model.

How to improve and restore soil health over time

Improving soil health is usually a gradual process, making it important to focus on consistent management changes supported by good data, rather than ‘quick fixes.’

Start with data and baseline testing

Understanding current soil condition is the first step. Baseline soil testing, paddock (and production history) assessment, and benchmarking help identify the main constraints and guide realistic targets for how to restore soil health.

Adjust management practices gradually      

Big or rapid changes can introduce risk. Incremental adjustments allow producers to evaluate outcomes under local conditions.

Examples include:

• Reducing cultivation frequency
• Increasing ground cover
• Improving crop rotations
• Adjusting fertiliser strategies
• Managing traffic and compaction.

Use technology and innovation to support outcomes

New tools are improving the ability to monitor and manage soil condition in real time.

Innovations such as the Soil Co-operative Research Centre’s QUOLL e-nose soil health monitoring tool, and the University of Tasmania’s applied research into soil health for Australian apple and pear orchards, show how technology, data, and field trials are helping producers measure soil performance more accurately and make better management decisions.

Connect with grow^AG. 

Improving soil health is a shared priority across producers, researchers, and agtech developers working to strengthen agricultural productivity alongside environmental health.

grow^AG. connects industry with research, innovation, and investment opportunities that support practical improvements in soil condition and farm performance.

Explore current funding & grants supporting soil R&D, or view technology investments focused on the next generation of tools for measuring, managing, and improving soil health.