9 May, 2018
New fertilizers for sustainable forestry
Torgny Näsholm is awarded the 2018 Marcus Wallenberg Prize. Photo: Johan Marklund
Torgny Näsholm has been awarded the 2018 Marcus Wallenberg Prize for having documented how trees use amino acid molecules as sources of nitrogen. He has also shown how this organic nitrogen dominates the nutrition of trees in boreal forests. The findings have resulted in new types of fertilizers.
Professor Torgny Näsholm, The Swedish University of Agricultural Sciences, Umeå, Sweden, has examined the role of amino acids in supplying the nitrogen required for the growth of forest trees. His work has caused a paradigm shift in explaining the nutrition of plants. For his discoveries, Torgny Näsholm is awarded the 2018 Marcus Wallenberg Prize of SEK 2 million.
The ability of boreal forests to take up atmospheric carbon dioxide and produce wood depends on the availability of nitrogen in the soil. The growth of most forests is however limited by a low supply of nitrogen.
Some species have developed symbioses with bacteria that can process nitrogen gas into amino acids. More than a century ago some plants were demonstrated to have the capability of taking up amino acids directly. The process was not considered important until the isotopic methods were further developed and could simplify chemical analyses of different elements.
Torgny Näsholm has in different studies since 1998 investigated the nutrition of forest trees - particularly Scots pine and Norway spruce. He found that nitrogen from amino acids was taken up by tree seedlings and discovered that the amino acid concentrations in forest soils are high enough to provide a substantial supply for tree uptake. He could also testify that the major nitrogen source of pine and spruce in boreal forests is amino acids rather than ammonium ions or nitrate.
The new insights inspired Torgny Näsholm to develop fertilizers based on amino acid and nitrogen. Field studies revealed the improvement of shoot growth when seedlings were grown on this organic nitrogen. Leaching of nitrogen was also reduced compared to conventional inorganic fertilizers. The findings have had an impact on nursery and forestry practices in coniferous forests in the Nordic countries.
The first patent for this approach was issued in 2000 and a fertilizer called Argrow, based on the amino acid arginine, was introduced on the market. Arginine is a nitrogen rich amino acid that is easily absorbed by plants. The fertilizer is mainly used in forest nurseries in Sweden, Finland, USA, Canada, Uruguay, China, New Zealand and Australia. It is also being tested on other commercial crops and garden plants.
The innovation has been further developed. Subsequent patents have highlighted improved plant growth. The Prize Selection Committee of the Marcus Wallenberg Foundation states in its motivation that Torgny Näsholm has made innovative discoveries with substantial practical importance to a sustainable management of forests. He has managed to translate and transfer his groundbreaking scientific discoveries into useful applications.
Source: Friday Offcuts