1. Publication
  2. Research Highlights
  3. 2023

Optimum phosphorus fertilizer management can balance productivity and quality of black rice

Related Research Project
Indigenous crops and foods design
Country
Asia

Description

The Southeast Asian region has a rich tradition of utilizing black rice for its medicinal properties. Black rice pericarp contains various secondary metabolites such as anthocyanins, which are known for their antioxidant effects including restoring liver function and preventing dementia. In tropical areas such as Laos, where black rice is commonly consumed, soils typically lack phosphorus (P), an essential nutrient for crops. Therefore, external P supply is crucial to boosting productivity. However, with rising fertilizer costs and the adoption of labor-saving rice cultivation techniques, it is vital to determine the optimal P fertilization levels. Additionally, understanding the impact of P fertilization on flavonoid accumulation, which contributes to antioxidant properties, is necessary. This study aims to conduct pot trials using P-deficient soil to evaluate how soil P availability affects black rice yield and flavonoid content, which serves as an indicator of antioxidant capacity. The goal is to identify the optimal P fertilization strategy to balance productivity and quality in black rice cultivation.

Pot trials conducted on volcanic soils with limited P availability revealed that P fertilization enhances yield up to a certain point but becomes excessive beyond 250 mg P2O5 pot-1 (Fig. 1). Exceeding this threshold not only fails to further increase yield but also reduces flavonoid content (Fig. 2) and affects the rice's appearance by lightening its color (Fig. 3). Therefore, P fertilization beyond 250 mg P2O5 pot-1 compromises both flavonoid accumulation and appearance traits.

These findings underscore the importance of careful P fertilization management in P-deficient soils. While it boosts black rice yield, excessive fertilization negatively impacts flavonoid content and appearance quality. Thus, adopting proper P fertilizer management practices is essential for producing high-value black rice that maintains a balance between productivity, functionality, and appearance quality. This knowledge can guide cultivation practices tailored to diverse soil conditions in different regions.

Figure, table

  1. Figs
Research project
Program name

Food

KAKEN
Term of research

FY2021-2023

Responsible researcher

Aung Zaw Oo ( Crop, Livestock and Environment Division )

Asai Hidetoshi ( Crop, Livestock and Environment Division )

KAKEN Researcher No.: 30599064

Takai Toshiyuki ( Crop, Livestock and Environment Division )

KAKEN Researcher No.: 40547725
MIERUKA ID: 1769

Tanaka Pariasca-Juan ( Crop, Livestock and Environment Division )

Marui Junichiro ( Biological Resources and Post-harvest Division )

MIERUKA ID: 001765

Nakahara Kazuhiko ( Biological Resources and Post-harvest Division )

KAKEN Researcher No.: 90241778
MIERUKA ID: 001774

SAITO Hiroki ( Tropical Agriculture Research Front )

Kawamura Kensuke ( Social Sciences Division )

ORCID ID
0000-0002-2824-1266
KAKEN Researcher No.: 90523746
MIERUKA ID: 1747

Win Khin Thuzar ( National Agriculture and Food Research Organization (NARO) )

ORCID ID
0000-0002-4834-078X

ほか
Publication, etc.

Oo et al. (2023) Front. in Sustain. Food Syst. 7:1200453.
https://doi.org/10.3389/fsufs.2023.1200453

Japanese PDF

2023_B05_ja.pdf387.18 KB

English PDF

2023_B05_en.pdf206.39 KB

＊ Affiliation at the time of implementation of the study.

Related Research Highlights