**Paweł Radzikowski \*, Mariusz Matyka and Adam Kleofas Berbe´c**

Department of Systems and Economics of Crop Production, Institute of Soil Science and Plant Cultivation—State Research Institute, Czartoryskich 8, 24-100 Puławy, Poland; mmatyka@iung.pulawy.pl (M.M.); aberbec@iung.pulawy.pl (A.K.B.) **\*** Correspondence: pradzikowski@iung.pulawy.pl; Tel.: +48-81-4786820

Received: 28 October 2020; Accepted: 9 December 2020; Published: 14 December 2020

**Abstract:** A growing interest in the cultivation of non-food crops on marginal lands has been observed in recent years in Poland. Marginal lands are a refuge of agroecosystems biodiversity. The impact of the cultivation of perennial industrial plants on the biodiversity of weeds and arthropods have been assessed in this study. The biodiversity monitoring study, carried out for three years, included five perennial crops: miscanthus *Miscanthus* × *giganteus*, cup plant *Silphium perfoliatum*, black locust *Robinia pseudoacacia*, poplar *Populus* × *maximowiczii,* and willow *Salix viminalis*. As a control area, uncultivated fallow land was chosen. The experiment was set up in eastern Poland. A decrease in plant diversity was found for miscanthus and black locust. The diversity of arthropods was the lowest for the cup plant. No decrease in the number of melliferous plants and pollinators was observed, except for the miscanthus. The biodiversity of plants and arthropods was affected by the intensity of mechanical treatments, the fertilization dose, and the use of herbicides. The biodiversity also decreased with the age of plantation.

**Keywords:** biological diversity; marginal land
