Lithologically diverse Nordic glacial flours as macro- and micronutrient sources for northern plants
Authors
Colin Sinclair (presenting author) [1, 2]
Jemma Wadham [1, 2, 3]
Laura Jaakola [4, 5]
Sabina Strmic-Palinkas [1, 2]
Affiliations
- The Arctic University of Norway, Department of Geosciences, Tromsø, Norway
Email (presenting author): colin.sinclair@uit.no - IC3: Centre for Ice, Cryosphere, Carbon and Climate, Department of Geosciences, UiT The Arctic University of Norway, Tromsø, Norway
Email (presenting author): colin.sinclair@uit.no - University of Bristol, School of Geographical Sciences, Bristol, UK
- The Arctic University of Norway, Department of Arctic and Marine Biology, Tromsø, Norway
- Norwegian Institute of Bioeconomy Research (NIBIO), Division of Food Production and Society, Ås, Norway
Keywords
Nutrient Cycling; Biogeochemistry; Agrogeology; Soil Fertility; Carbon Sequestration
Abstract
In recent years, rock powders have received renewed interest as slow-release fertilizers that can provide soils and crops with a wide range of macro- and micronutrients. Glacial flour is a naturally occurring, fine-grained rock powder that is found in glaciated regions worldwide. Formed from the erosion of bedrock, the physical and chemical properties of different glacial flours vary widely depending on their sources, influencing their effectiveness as fertilizers. This study aimed to analyze eight lithologically diverse glacial flours collected from glaciers in Iceland, Svalbard, and Norway for their exchangeable and total nutrient concentrations, trace metal concentrations and mineralogy. The flours were then applied to a nutrient-depleted, artificial soil at three different application rates in a controlled greenhouse experiment set up to mimic a short, Arctic/subarctic growing season for the crop, pea (Pisum sativum L.). The flours were found to contain low amounts of plant-available N and P. Analyses for potassium, total nitrogen, trace elements, and mineralogy are ongoing. Glacial flour treatments, even at the lowest application rate of 2 tha-1, improved pea biomass and yield over the control, and produced similar results to a low dose of a synthetic PK fertilizer. The magnitude of biomass and yield increases compared to the control varied amongst the glacial flour treatments, but did not always increase with the flour application rate. Trial results indicate that peas benefited from glacial flour amendment of soils over a single growing season under conditions of severe nutrient limitation. Preliminary results indicate that glacial flour has potential utility in organic and regenerative agriculture, but suitable flours must be identified based on total nutrient concentrations, nutrient availability, dissolution rate, and potentially harmful trace metal concentrations.
Funding
UiT, Changing Arctic Research School, Glacier GEOHEALTH: A solutions-based approach to the impacts of glacier retreat on ecosystem and human health in a changing Arctic