Crop species and year affect soil-dwelling Collembola and Acari more strongly than fertilisation regime in an arable field

Drivers of soil-dwelling microarthropods represent one of the most addressed topics in soil ecology, and diverse results have been reported in the literature. In the present study, an extremely long-term fertilised monoculture system provided a special opportunity to investigate the drivers of soil-dwelling springtail and mite assemblages. The cropping system included wheat and maize monoculture and biculture and was managed with mineral and organic fertilisers for over 50 years. Soil samples were collected two times a year for two years from four blocks. Soil-dwelling mite groups and springtail orders were identified and analysed based on soil characteristics and compared amongst different treatments to reveal the drivers. In addition, oribatid mites and springtails were identified at the species level and analysed. The most important parameters were ‘crop species’ and ‘study year’. Most Collembola and Acari groups were more abundant in wheat plantations, and there were yearly variations within different mite and collembolan groups. Fertilisation appeared to produce no effect on microarthropod assemblages; however, soil pH and phosphate concentration differed according to fertilisation treatment. Overall, the four blocks at the study site effectively reflected the spatial patterns of oribatid species. Specifically, the dominant collembolan species exhibited similar patterns to the major collembolan orders, whereas oribatid species presented different patterns within Oribatida. The studied special agricultural system helped reveal important drivers of soil-dwelling Collembola and Acari, and these soil-dwelling microarthropod assemblages are affected more strongly by ‘crop species’ and ‘study year’ than by long-term fertilisation regime.