Abstract

Rawanbuki, a variety of Japanese butterbur (Petasites japonicus subsp. giganteus), grow naturally along the Rawan River, Hokkaido, northern Japan. Most plants reach 2–3 m in height and 10 cm in diameter in 2 months and are much larger than those grown along other rivers. We examined the hypothesis that nutrients exported from upland streams enhance the growth of the Rawanbuki. Nutrient concentrations, including nitrogen, phosphorus, and base cations, in the Rawan River were much higher than those in rivers of adjacent watersheds. High nutrient concentrations and moisture contents were found in soil along the Rawan River and a significant relationship was found between physicochemical soil conditions and aboveground biomass of butterburs. This indicates that extremely large Rawanbuki plants could be caused by these high nutrient concentrations and moisture contents in the soils. A manipulation experiment showed that fertilization simulated the growth environment along the Rawan River and enhanced the stem height and stem diameter of butterburs. This study concluded that the extremely large butterburs are caused by a large amount of nutrients exported from upland areas. These results are the first demonstration of the role of stream water nutrients in enlarging agricultural crops.

Details

Title
Nutrients exported from upland stream water enlarge perennial biomass crops
Author
Chiwa Masaaki 1 ; Utsumi Yasuhiro 1 ; Tashiro Naoaki 1 ; Yasuda Yuko 2 ; Shinozuka Ken’ichi 3 ; Yang, Ru 1 ; Nagano Nao 1 ; Murata Shusuke 1 ; Nakamura Takuma 1 ; Yamauchi Kohei 1 ; Kabemura Yuji 1 ; Ando Tatsuro 4 ; Sawamura, Hiroshi 4 

 Kyushu University Forest, Kyushu University, Fukuoka, Japan (GRID:grid.177174.3) (ISNI:0000 0001 2242 4849) 
 Kyushu University Forest, Kyushu University, Fukuoka, Japan (GRID:grid.177174.3) (ISNI:0000 0001 2242 4849); Forestry and Forest Products Research Institute, Tsukuba, Japan (GRID:grid.417935.d) (ISNI:0000 0000 9150 188X) 
 Kyushu University Forest, Kyushu University, Fukuoka, Japan (GRID:grid.177174.3) (ISNI:0000 0001 2242 4849); Fukuoka Institute of Technology, Fukuoka, Japan (GRID:grid.418051.9) (ISNI:0000 0000 8774 3245) 
 Ashoro Museum of Paleontology, Ashoro, Japan (GRID:grid.177174.3) 
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2480546920
Copyright
© The Author(s) 2021. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.