Improving agricultural productivity of podzolic soils in Schefferville using local amendments and fertilizers

The Indigenous communities of Matimekush (Innu) and Kawawachikamach (Naskapi), in Schefferville, northern Quebec, have limited access to fertile soils and agricultural inputs. Therefore, horticultural materials must be imported leading to high costs and significant environmental impacts. This study aimed to enhance the fertility of Podzolic soils in the northern Quebec Taiga using locally sourced fertilizers and amendments. Two types of humus were tested: Mor-type humus (pH 3.59; C/N ratio 49.5) collected near Matimekush and Mull-type humus (pH 5.0; C/N ratio 17.1) collected in Kawawachikamach. Two local rocks were identified as potential basic mineral amendments: a dolomitic rock (pH 8.6) and a sedimentary rock (pH 7.5), both sourced near Matimekush. Furthermore, a compost (N-P-K: 3-1-3; C/N ratio 10.4) produced from plant-based food waste and green alder ( Alnus Viridis ssp. Crispa) was tested alongside a mineral fertilizer with an equivalent nutrient profile. Greenhouse experiments were conducted to assess the agronomic performance of these materials using carrot and radish cultivation as bioassays. The results demonstrated that the local dolomitic rock exhibited a liming capacity comparable to commercial lime, whereas the sedimentary rock was ineffective. Mull-type humus produced carrot and radish yields equivalent to those obtained with commercial sphagnum peat (pH 3.7; C/N 37.3) without requiring pH adjustment. Organic fertilization significantly increased yields, supporting the agronomic value of the locally produced compost. These results highlight the potential of utilizing local substrates to improve Podzolic soil fertility and promote sustainable agriculture, representing a first step toward the establishment of agricultural practices in the region.