Soil health in orchards; the role of Collembola as key indicators

The benefits of soil ecosystem research to agricultural productivity, conservation planning, the management of global change, and the maintenance of ecosystem services have been demonstrated internationally. Collembola (springtails) have proven to be useful model organisms in other parts of the world, as they respond to a variety of environmental factors and are well represented in the soil in terms of diversity. This project aimed to determine if the presence of Collembola assemblages responds to different management strategies (with mulch and without mulch) in orchard sites.

Four sites in Ceres were identified and sampled.  A total of 480 samples were collected across four sites and three seasons. In addition, a shaded and non-shaded site has been sampled. Samples were being sorted and morphospecies were identified using taxonomic methods and DNA barcoding, contributing to the identification of the unknown species. A total of 32 soil samples were collected and analysed for several soil parameters.

A total of 480 samples were collected over three seasons. Over 18,400 springtails were counted, consisting of 33 morphospecies from 11 families. Collembola (springtail) communities differed in sites using mulch compared to sites not using mulch, especially during summer months. Mulch may play an important role in buffering and maintaining these beneficial Collembola populations throughout the year.

This study concluded that Collembola showed seasonal variation as well as that mulches maintain overall Collembola abundance and species richness within the orchard. Furthermore, Collembola community structures are only dissimilar in the mulched bankie compared to that of the work row in mulched sites, particularly leading up to summer. Collembola species richness in some cases may also be significantly different in the bankie compared to the row in mulched sites, indicating the importance of location when sampling Collembola. This study is the first detailed study of Collembola diversity in apple orchards as well as the first investigation of Collembola under shade nets in Africa, and provides important baseline knowledge for future work.

Collembola (springtail) communities differ in sites using mulch compared to sites not using mulch. Mulch may play an important role in buffering and maintaining these beneficial Collembola populations throughout the year.