Sustainability is a primary goal of organic farming systems, particularly with regard to environmental factors.
Modern orchard systems in general benefit from the perennial nature of the crop and the reduced impacts to soil and water with the absence of tillage.
In the Pacific Northwest region of the USA, most pome and stone fruit orchards utilize herbicides to manage weeds in the tree row, and a perennial grass cover in the drive alley to reduce dust and provide a stable surface for machinery traffic.
Organic orchards in the region do not have an acceptable herbicide option, and thus typically rely on weed control through soil tillage, which can compromise soil quality.
Tillage was compared with wood chip mulch and an undisturbed control in a 3-yr trial.
Tillage did not lead to consistent soil quality decline; however, it did lead to poorer tree performance relative to the control, while wood chip mulch improved tree performance.
Both options provided good weed control.
Related trials with living mulch in the tree row showed soil quality benefits and meaningful N contribution, but had severe competition with trees and elevated vole populations.
Results to date suggest that an integration of practices will be needed to optimize sustainability.