Straw was very effective during the summer, especially on replicates 1-3, where stable straw was used. This broke down rapidly from January onwards, apparently assisted through disturbance by birds, which probably increased weed control by preventing seedling establishment. Pukekos were often in evidence in the orchard. It is difficult to predict the effect that soil temperature changes caused by mulching may have on trees. The reduced fluctuations on mulched plots may be advantageous by reducing extremes but this was accompanied by a lower mean temperature.
Any effect is also likely to be reduced as tree canopy expands to shade the soil.
All species and age groups of earthworms were adversely affected by sawdust and wooldust. Straw and compost were both favoured by worms with particularly high numbers of juveniles present. The absence of organic matter from weeds in the straw plots would have been compensated for by the decomposing straw. The increase in boron content of the leaves and fruit on the compost treatment suggests some high boron component in the compost. However, trunk cross-section area growth was increased and fruit yield decreased by the compost mulch.