Effects of soil characteristics and farm types on earthworm populations in Hungarian organic, permaculture and conventional farms

Abstract Farming systems with differing intensities have various impacts on soil biota. The objective of our study was to assess the effects of different farm types (conventional, organic and permaculture) and soil characteristics on earthworm populations. The main consideration was that scientific knowledge on permaculture farms in regards to soil fauna is missing. According to our hypothesis permaculture farms provide the most ideal conditions for earthworms. Fifteen micro-farms (0.3–2 ha) with similar agro-ecological features were selected for comparison in the North-Central part of Hungary. These were all horticultural farms with diverse crop rotations. The basic difference was the intensity of the farming activities. Earthworms were sampled in May and September (2020) with six replicates on each farm (90 samples in total). Earthworms found in the 25×25×25 cm soil blocks were hand-sorted. Five soil samples from each site were analysed for texture, pH, soil organic matter, macro- and micronutrient content in September (2020). Seven endogeic and three epigeic earthworm species were detected. In September species numbers were higher, in the average of the earthworm species number and Shannon diversity there were lower differences, a stronger positive relationship was found between CaCO 3 content and earthworm abundance, adult earthworm average was strongly and positively affected by magnesium content. Earthworm species number was significantly higher in permaculture farms while earthworm abundance was also significantly higher but only in May. This partly validates our zero hypotheses that permaculture farms have the best performance in providing good conditions for earthworm populations.