All about SOIL - Differences in health & degraded soil properties

Soil health as a foundation of sustainable agriculture 

The critical role of soil in ecosystem stability 

Soil represents one of the most fundamental resources supporting ecosystem stability and efficient crop production. A recent review article by Hartmann & Six (2022) delves deep into the intricate relationships between soil structure and microbiome functions, highlighting their profound impact on agricultural productivity. 

Characteristics of healthy soil structures 

Structurally intact and healthy soils are distinguished by several key characteristics: 

1. Aggregate stability and formation 

Well-developed soil architecture is a robust, interconnected soil structure that supports complex ecological interactions.  

Soil aggregates are the building blocks of soil structure. In healthy soils, these aggregates are well-formed and stable. They are composed of mineral particles, organic matter, and biological binding agents. Soil aggregates are also resistant to erosion and physical breakdown, and capable of maintaining their structure under various environmental stresses. 

2. Porosity and structural complexity 

Optimal soil structure features interconnected pore spaces of varying sizes (macropores for water drainage or root movement and micropores for water retention). Channels are created by root systems and soil fauna. Optimal water and oxygen flow enables critical biological processes and supports plant growth. 

3. Root and mycorrhizal network development 

Enhanced root and fungal networks facilitate efficient nutrient exchange and communication between plant roots and soil microorganisms. 

Healthy soils support extensive and complex underground networks that enhance nutrient and water exchange mechanisms. They are well-developed root systems with extensive branching. Symbiotic mycorrhizal fungal networks interconnects plant roots.  

Well-developed root and mycorrhizal networks improve plant communication and resource sharing. It also increases resilience to environmental stressors. 

4. Biological activity and diversity 

Increased biodiversity through a rich, active microbial ecosystem enhances nutrient availability and soil health. In healthy soil, diverse microbial communities occur (bacteria, fungi, actinomycetes). 

A hallmark of healthy soil structures is vibrant biological activity such as high enzymatic activity, efficient nutrient cycling mechanisms, active decomposition processes, and continuous organic matter transformation. 

Microorganisms play a crucial role in aggregate formation. Fungi, bacteria, and their extracellular polymeric substances act as natural glues, binding soil particles together and creating stable, porous structures. 

5. Water management capabilities 

Structurally sound soils excel in water dynamics, with rapid water infiltration, effective water retention, reduced surface runoff, minimized erosion risks, balanced moisture levels supporting plant growth, and the ability to withstand both drought and heavy rainfall conditions. 

6. Nutrient retention and availability 

Healthy soil structures optimize nutrient management. It is based on high cation exchange capacity, efficient nutrient adsorption and release mechanisms, reduced nutrient leaching, balanced pH levels facilitating nutrient uptake, and continuous nutrient cycling through biological processes 

7. Resilience and adaptability 

Robust soil structures demonstrate resistance to compaction, quick recovery from physical disturbances, ability to maintain functionality under changing environmental conditions, and sustained productivity across different agricultural practices. 

The intricate relationship between soil structure and microbiome 

The soil microbiome is not just a passive component of the soil ecosystem—it is an active, dynamic system intrinsically linked to soil structure. Microorganisms regulate the flow of water, oxygen, and nutrients, creating favorable conditions for specific microbial communities to thrive. 

Challenges in assessing soil health 

Evaluating the biological condition of soil is complex due to its highly intricate nature. Traditional assessment methods often fall short of providing comprehensive insights. This is where advanced technologies like BIOTREX come into play, offering credible and repeatable soil health assessments, simple, interpretable scoring systems, and comparative analysis capabilities. 

Conclusion 

Understanding and maintaining soil health is crucial for sustainable agriculture, ecosystem preservation, and global food security. By investing in soil conservation techniques and leveraging advanced assessment technologies, we can work towards protecting this vital resource.

Source: Image: differences in soil properties between structurally intact versus degraded soils (credits: Hartmann & Six 2022; doi: 10.1038/s43017-022-00366-w)