Is Rockwool Potentially Harmful to the Soil Environment as a Nursery Substrate? Taking Eisenia fetida as an Example for Toxicological Analysis

We studied the effect of rockwool matrix on the conventional physical and chemical properties of soil and analyzed its toxicological effect on Eisenia fetida. The physical and chemical properties of rockwool were studied with characterization tests. By measuring earthworm enzymes and earthworm intestinal microorganisms, the effects of different rockwool particle sizes and additive amount on Eisenia fetida were analyzed. The results indicate that a low concentration of rockwool (<30 g/kg) had little effect on the soil physicochemical properties and the activity of Eisenia fetida, and played a positive role in improving the soil porosity. A high concentration of rockwool (>100 g/kg) reduced the exchangeable Ca and Mg content in the soil, and had a significant impact on the enzyme activity of Eisenia fetida. Mechanism studies have shown that high concentrations of rockwool (>200 g/kg) can have a significant impact on the nervous system of earthworm tissue. In addition, small particle size and low concentration of rockwool is conducive to the increase in intestinal microbial species of Eisenia fetida. This study clarifies the effects of emerging rockwool substrates on soil and soil organisms and provides theoretical support for the safe and reliable application of rockwool substrates in agricultural production.