Soil Organisms (Dec 2021)
Assessing a ReviTec Measure to Combat Soil Degradation by studying Acari and Collembola from Ngaoundéré, Adamawa, Cameroon
Abstract
Acari and Collembola from a high Guinean savanna and an experimental ReviTec site were studied to assess the efficiency of compost and biochar amendments for the rehabilitation of degraded soil. The research sites are located in Dang (Ngaoundéré, Adamawa, Cameroon), which is subject to four months of dry season. Our study contributes to the suitability of microarthropods as bioindicators of a rehabilitation measure and to the general knowledge of soil mesofauna in dry sub-Sahara Africa savanna. Abundances of soil Acari and Collembola were assessed in four sampling campaigns during the rainy season (May, June, July, August 2017; 0–20 cm depth). Results from explorative sampling campaigns in the same months of 2016 are included to assess year-to-year development (0–10 cm depth). Soil water content, pH, N, C and soil temperature were monitored. Controls were savanna (adjacent to the experimental site) and ReviTec control (part of the experimental site). To assess the effect of compost and biochar soil amendments, we investigated compost + mycorrhiza (cpmy) and compost + biochar + bokashi (cpbcbo). We identified Acari groups (Gamasina, Uropodina, Prostigmata, Oribatida, Astigmata) and Collembola, extracted with a Tullgren-type apparatus. In the savanna, abundances of up to 23 tsd. Acari and 6 tsd. Collembola per m2 were recorded. The corresponding findings for the compost-amended substrates of the ReviTec site are 228 tsd. Acari and 37 tsd. Collembola per m2 (2017, means of five cores). The abundances increased gradually with the duration of the rainy season and reached their maximum in July/August. Abundances were higher at depths of 0–10 cm than at 10–20 cm, except in May. Abundances in May likely reflect the previous dry season, when animals seem to survive in deeper soil layers. Significantly higher abundances were recorded in the ReviTec substrates than in the control soils. The development of microarthropods indicates effective rehabilitation of ecosystem services of degraded soil after application of ReviTec.
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