Table 3 Soil health indicators used in the study and their relevance to soil and crop health.

pH

Controls nutrient availability, influences microbial communities, and soil processes

A soil pH of 5.5–7 is ideal for most crops to obtain necessary nutrients

POXC

Measure of reactive carbon pool readily accessible to microbes and is very strongly correlated with other indicators of soil health like total organic C (TOC)⁶²

Soil carbon pools are important for maintaining soil function imperative to plant growth, shown to affect agronomic performance⁶³

Carbon fractions

Changes in soil organic carbon (SOC) require decades. C fractionation can show faster changes (Particulate organic matter- POM) as well as indicate the stability of the soil C (mineral-associated organic matter- MAOM). POM also plays roles in soil aggregation and infiltration

POM is primary source of plant available N. SOC is important for controlling soil functions (e.g. water and nutrient regulation) imperative for plant growth

Water infiltration

The amount of water able to move though soil and is related to soil compaction, pore space, and water retention abilities

Important component of plant water availability and compaction affecting root growth

Microbial abundance

Microbes are the base of the trophic chain and important players in decomposition, nutrient availability, and C storage

Plants benefit from easily available nutrients, increased SOC, and improved soil structure supported by microbial processes. Increased microbial diversity has been linked to plant health and growth⁶⁴

Microbial diversity

Higher microbial functional diversity can support more soil processes and healthier soils⁶⁵