Orchard floor management and soil health in deciduous fruit orchards

The development of integrated orchard floor management methods is critical as they will allow for more sustainable fruit production. Current information on orchard floor management is limited. It is proposed that various combinations of cover crops be planted and assessed in order to determine the basic information needed. The two trial sites selected are in separate climatic zones, these are Koue Bokkeveld and Warm Bokkeveld

Objective 1: Establish four cover crop treatments in tree rows and work rows in two climatic areas Objective 2: Assess cover crop performance and the long term effects of the various management practices on soil ecology and yield by means of soil analyses and biological assessments.

Objective 3. Assessment of additional cover crop species at a small scale in two climatic areas by means of small scale plantings of various suitable plant species..

Cover crops were planted in May 2018 and under tree treatments were applied. Various performance and biological parameters have been measured and assessed. The overall performance of the various treatments was deemed satisfactory. Differences between treatments in both tree rows and work rows were difficult to differentiate. Natural plant succession occurred in all treatments over time. Soil biology was disrupted by cultivation but recovered over time. The various assessment methods used were applicable but nematode diversity and certain elements of the soil analysis proved very valuable.

Planted cover crops in work rows are beneficial. The influence of plant diversity in cover crops was not evident in the trial sites over time due to natural plant succession . Cultivation was very disruptive to soil ecology which recovered over a number of seasons. A number of methods were used  to assess soil health, nematode diversity and soil biological measures proved useful. Flowering cover crops were found to be beneficial in promoting bee visitation of blossoms.

The use of cover crops and under  tree mulches is beneficial. However, orchard floor ecology is complex and difficult to measure. The trial has provided a large amount of data and insights to soil ecology. In addition, a variety of assessment methods were used and compared. Nematode diversity and Haney soil tests proved to be particularly useful.