Investigating the effect of subsoil manuring on soil arthropods in the northern midlands of Tasmania

A study was carried out as part of a larger trial into the soil amelioration technique called subsoil manuring (SSM). This technique involves the use of a deep ripper to directly place organic amendments into the upper layer of the subsoil of duplex soils which have significant constraints to crop growth. In this study, soil arthropods were extracted from topsoil and subsoil samples from three sites (two irrigated and one dry land) on duplex soils in the northern midlands of Tasmania. There were a total of five different SSM treatments: control, deep-ripped only, and deep-ripped with a range of organic amendments including poultry manure and poppy seed meal. Arthropods were extracted from soil samples using a Burlese-Tullgren funnel apparatus and identified to arthropod order. Two orders, acari and collembola, were dominant and used for further analysis. The acari were further separated into the suborders mesostigmata and oribatida. Data from the sites was collected and analysed separately and then the mesostigmatid population between treatments was compared across all sites. There was a significantly higher abundance of mesostigmatid mites in the plots that had an organic amendment added to the subsoil. The dryland cereal site was more responsive to the treatments compared to the irrigated cropping sites.