Rock and rock dust are often promoted as soil amendments, but their effect on northern boreal farmland is disputed and largely untested.

A fast online search leads to numerous non-scientific articles that tout rock and rock dust as effective soil amendments for improving soil quality, enhancing carbon storage, and acting as a source of nutrients that reduces the need for fertiliser. The term 'rock', however, encompasses a wide range of materials, from alkaline limestone to volcanic tuff to acid basalts, and their effect on soil is disputed. For the acid soils of Newfoundland, rock dust might be effective in improving nutrient availability and plant yield, but there is not yet a structured research approach that translates data into farmer practice.

Northern agricultural soils often have rocky conditions that impede farm operations. To facilitate better tillage, large rocks may be pulverized by a rock crusher attached to a tractor, and the rock dust remaining after pulverization is mixed into the soil. It was hypothesised that pulverization would alter abiotic soil properties through increased acidity and nutrient concentrations, with soil respiration and nematode feeding communities used as biotic indicators of soil functioning.

Our study found no major differences from pulverization in soil properties, soil respiration, or nematode feeding types, indicating that rock pulverization in northern soils has value primarily for soil workability rather than improved enrichment or functioning. The differences between natural and agricultural sites were far greater than those between pulverized and non-pulverized agricultural soils. Variation in soil abiotic properties, particularly acidity, organic matter, and nutrient concentration, were the essential drivers of soil functioning.