They detail their results, which in fact promise to make an important contribution to food security also in tropical and subtropical developing countries, in the journal Scientific Reports.
Agricultural yields depend very much on plants' access to sufficient quantities of essential nutrients. One of the most important nutrients is phosphorus. Though often present in large amounts in soils, a large share of phosphorus is strongly bound, especially to iron, which in turn is a component of various minerals. As a result, this phosphorus is immobile and not available to the plants. Consequently, huge amounts of phosphorus-based fertilizers are utilized in agriculture today, to achieve the highest yields possible.
The interdisciplinary research team led by Dr. Jörg Schaller (Bayreuth) and Prof. Dr. Bo Elberling (Copenhagen) have now found a way to make large amounts of the phosphorus yet strongly bound in soils available to plants. Silicon mobilizes phosphorus from iron minerals, and enables it to be taken up by the roots of plants. When farmers add precisely measured doses of silicon to their soils, they can do without phosphorus-based fertilizers for a certain period, in some cases extending over several years, without any reduction in yield. "The environmental and agricultural advantages are obvious", Schaller emphasised. "Phosphorus-based fertilizers are a limited resource, whereas silicon is in virtually endless supply. On the basis of our research results, the worldwide availability of phosphorus in the ground could be precisely controlled by targeted fertilizing with silicon. This would represent an important contribution to global food security", the Bayreuth environmental geochemist explains. Especially in tropical and subtropical developing countries, several soils contain high amounts of strongly bound phosphorus, which could be mobilized bit by bit through the controlled application of silicon fertilizer.
This would mean making a significant contribution to environmental protection: A reduction in fertilization with phosphorus and the precise control of phosphorus availability through silicon would lead to far less phosphorus leaching from fields to the aquatic ecosystems. Hence, the environmentally damaging eutrophication of waters (algal bloom) would be reduced. Moreover, the enrichment of soils with silicon has one further ecological advantage: It results in a higher silicon transport from soils into the sea. As a result, more carbon might be bound in the oceans through increased diatoms biomass production, instead of remaining in the atmosphere as a greenhouse gas.
The scientists from Bayreuth and Copenhagen actually gained all of these insights through studies of arctic soils. Soil samples were taken from over 150 sites on the Swedish mainland, on Svalbard, the north coast of Russia, and on Greenland, which were subsequently subjected to extensive analyses and experiments. For research into geochemical processes, permafrost soils have the advantage of not being influenced by agriculture or other human activity. "In selecting the soil samples, we made sure that the respective regions differed from one another as much as possible - for example in regard to soil types, landscape profile, and vegetation. In this way we wanted to ensure that our research results were not due to specific regional factors, but as far as possible, could be applicable globally", Schaller explains.
Various research areas of the Bayreuth Centre of Ecology & Environmental Research (BayCEER), an inter-disciplinary research centre of the University of Bayreuth, collaborated on the study which has now appeared in Scientific Reports: Environmental Geochemistry, Experimental Biogeochemistry, and Hydrology.
Study: J. Schaller, S. Faucherre, H. Joss, M. Obst, M. Goeckede, B. Planer-Friedrich, S. Peiffer, B. Gilfedder, and B. Elberling:
Silicon increases the phosphorus availability of Arctic soils, Scientific Reports (2019), DOI: 10.1038/s41598-018-37104-6
Source:
Press Release Bayreuth Centre for Ecology & Environmental Research BayCEER, 24.01.2019