EM Soil & Crop within an integrated soil management programme
Ormond Nurseries in Marlborough is combining EM Soil & Crop, lime, cover crops and mob grazing with sheep to improve its nursery soils.
Soil testing in its River Block recorded encouraging changes between March and August 2026, including a 27% increase in estimated microbial biomass carbon, a 32% increase in hot water extractable carbon, and an increase in reported organic matter from 3.5% to 4.9%.
An active approach to soil improvement
Led by Field Nursery Manager Tomas Mercau Bridger, the programme focuses on actively managing the soil through plant growth, biological inputs and grazing.
Tomas describes the approach as a triple-M system: Mob → Mow → Move. Cover crops and managed sheep grazing complement EM Soil & Crop and lime, with the longer-term aim of building organic matter, supporting nutrient cycling and improving soil structure.
The nursery is working towards sustained improvements over approximately five years, using soil testing to track progress.
River Block results
Hill Laboratories analysed soil samples collected at a reported depth of 0–150 mm.
| Soil indicator | March 2026 | August 2026 | Change |
|---|---|---|---|
| Estimated microbial biomass carbon | 188 mg/kg | 239 mg/kg | +27% |
| Hot water extractable carbon | 1,244 mg/kg | 1,636 mg/kg | +32% |
| Organic matter | 3.5% | 4.9% | +1.4 percentage points |
| Total carbon | 2.0% | 2.8% | +0.8 percentage points |
| Anaerobically mineralisable nitrogen | 64 µg/g | 103 µg/g | +61% |
What the results indicate
The River Block recorded positive changes across several soil carbon and nitrogen indicators during the programme.
Hot water extractable carbon, a measure of the labile organic matter fraction associated with soil microbial biomass, increased by 32%. Estimated microbial biomass carbon rose by 27%. These measures are linked: Hill Laboratories calculates its microbial biomass estimate from hot water extractable carbon using a published correlation, rather than measuring microbial biomass independently.
Reported organic matter increased from 3.5% to 4.9%, while anaerobically mineralisable nitrogen increased by 61%, indicating a larger potentially mineralisable nitrogen pool under laboratory test conditions.
These results provide an encouraging starting point for tracking the nursery’s longer-term soil management goals.
The River Block provides a promising example of EM Soil & Crop being incorporated into an integrated programme that recorded improvements in soil carbon and nitrogen indicators.
