Effects of heavy application of phosphate fertilizer on cadmium dynamics in upland fields

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05367
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38010:Plant nutrition and soil science-related
• Research Institution: Obihiro University of Agriculture and Veterinary Medicine
• Principal Investigator: Tani Masayuki 帯広畜産大学, グローバルアグロメディシン研究センター, 教授 (00271750)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: カドミウム / 普通畑土壌 / リン酸肥料 / カルシウム施肥 / バレイショ

Outline of Final Research Achievements

Volcanic ash soils called Andosols are widely distributed in large-scale upland fields in Hokkaido, and phosphorus, which is an essential element for crop growth, is fixed, so phosphate fertilizer has been heavily applied. However, rock phosphate, which is the raw material for phosphate fertilizer, contains harmful heavy metals such as cadmium, which may accumulate in the soil or be absorbed by crops.
As a result of this study, it was proved that cadmium is not easily absorbed by crops in Andosols and the cadmium concentration in potato tubers is low although a large amount of cadmium is accumulated in the upland soils together with phosphorus. Even in areas where other soils are distributed, it is possible to decrease the cadmium concentration in potato tubers by improving soil acidity and applying calcium fertilizers so that it does not affect our health.

Free Research Field

土壌学

Academic Significance and Societal Importance of the Research Achievements

本研究により、リン酸肥料を多施用してきた北海道の普通畑で生産されたバレイショ塊茎のカドミウム濃度は国際基準を下回っていることが明らかとなった。カドミウム濃度が高い地域では、適切な土壌改良と施肥管理により低下させることが可能であることも示された。
カドミウムは有害な重金属であり、カドミウムを含む作物可食部の摂取により人間の健康に直接的な影響がある。リン酸肥料などに含まれるカドミウムによる影響を明らかにすることは、安全な作物生産に貢献する社会的意義が非常に大きい重要な研究成果である。