Plant residue retention

On left a cultivated fieldwith no mulch retained compared with a field with zero tillage with a thick mulch layer.

In zero tillage cropping systems, a layer of mulch is retained on the soil surface and is not cultivated into the soil. Under these systems soil biota generally increase in abundance.

Effects of retention of organic surface residues on soil biota include:

• Increase in earthworm numbers (x6 times)
• Increase in springtails and mites
• Increase in microbial biomass