Cloudberry cultivation in cutover peatlands: hydrological and soil physical impacts on the growth of different clones and cultivars

Cloudberry (Rubus chamaemorus L.) cultivation is receiving increasing attention as a means of revitalising regional economy and rehabilitating cutover peatlands. The study reported here investigated the necessary soil physical and hydrological conditions, the compatibility of cloudberry cultivation with restoration of mined peatlands, and the performance of newly commercialised Norwegian cultivars in North America. Terraces at two levels were landscaped in peatland after vacuum extraction of peat to create different growing conditions in terms of hydrology and soil properties, then planted with two Norwegian cultivars (Fjordgull and Fjellgull) and two local (east Canadian) clones of cloudberry in a randomised block experiment. After three years, both the clones and the cultivars grown on the lower terrace had more leaves per m2 due to lower soil bulk density combined with higher average water level. Mulching, inherent to restoration, reduced the number of leaves produced during the year following planting. The Fjordgull cultivar had a higher survival rate than Fjellgull and local clones. Overall, the number of living rhizomes decreased over the years following planting. These results suggest that soil properties (bulk density and porosity) significantly influence cloudberry establishment and growth. Rhizomes should be planted two or three years after peatland restoration to avoid the initial negative effects of the mulch.