Soil water use from an apple orchard under various soil management systems

Commencing at field capacity, changes in soil moisture levels over fourteen-day drying periods were compared for mature apple trees under various soil management systems during spring and summer. In spring, the rate of loss under trees in a mown pasture was greater than under trees in cultivation or herbicide. In summer, the rate of loss under trees in uncontrolled summer weed growth after spring cultivation (trashy cultivation) was greater than under trees in mown pasture, clean cultivation or herbicide treatment, but the mown pasture did not differ from the bare land treatments. It is proposed that the influence of the tree on the microclimate at the soil surface is responsible for these effects. Differences in yield under the treatments were not statistically significant and there were no consistent differences in fruit growth rates over the whole season.