研究成果
Achieving Higher Rice Yields in Phosphorus-Deficient Paddy Fields in Sub-Saharan Africa
—Development of Sustainable Rice Cultivation Technology Using Farmyard Manure from Smallholder Farmers—
press202513.pdf1.04 MB
August 14, 2025
Japan International Research Center for Agricultural Sciences (JIRCAS)
Radiation Research Institute, University of Antananarivo
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Main Points
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Overview
JIRCAS, in collaboration with LRI (Laboratoire des RadioIsotopes/Radiation Research Institute) of the University of Antananarivo in Madagascar, examined the effects of farmyard manure (FYM)¹ used by smallholder farmers in the central highlands of Madagascar.
The recent surge in global chemical fertilizer prices has placed a heavy burden on farmers, especially those with low purchasing power. Under these circumstances, developing rice cultivation technologies that can stably increase yields without relying on chemical fertilizers has become an urgent priority.
This study demonstrated that the presence or absence of phosphorus (P) deficiency² in paddy soils has a clear impact on the effectiveness of FYM. In particular, in P-deficient paddy fields, application of FYM was found to increase rice yields. Furthermore, combining FYM with nitrogen fertilizer and applying them continuously for four years resulted in a substantial enhancement of yield gains.
To further validate these findings, literature was collected and analyzed for 13 field trials conducted in the sub-Saharan African region. Results showed that in P-deficient paddy fields, yield increases from FYM tended to be greater than in non-deficient soils, consistent with the findings of this study. This indicates that the use of FYM is effective not only in Madagascar but broadly across P-deficient soils in sub-Saharan Africa.
Going forward, it is expected that the dissemination of this technology—reducing the use of chemical fertilizers while serving as a sustainable rice production method—will contribute to improved food security and higher incomes for farmers in sub-Saharan Africa.
The results of this research have been published in the online edition of the international scientific journal Field Crops Research (May 13, 2025, JST).
Related Information
Part of this research was supported by funding from a Ministry of Agriculture, Forestry and Fisheries commissioned project for promoting international collaboration directly linked to national interests (Strategic International Collaborative Research Program): “Exploring novel rhizosphere functions of plants for environmentally friendly agriculture through the utilization of unused phosphorus.”
It was also supported by the SATREPS program (Science and Technology Research Partnership for Sustainable Development), a joint initiative of the Japan Science and Technology Agency (JST) and the Japan International Cooperation Agency (JICA): “Breakthrough in Nutrient Use Efficiency for Rice by Genetic Improvement and Fertility Sensing Techniques in Africa” (Principal Investigator: Yasuhiro Tsujimoto).
Published
- Authors
- ASAI Hidetoshi, Andry Andriamananjara (LRI, University of Antananarivo), Michel Rabenarivo (LRI, University of Antananarivo), Hobimiarantsoa Rakotonindrina (LRI, University of Antananarivo), TSUJIMOTO Yasuhiro, NISHIGAKI Tomohiro, TAKAI Toshiyuki, OKAMOTO Takanori
- Paper Title
- Selective application of farmyard manure to phosphorus-deficient soils improves rice yields in sub-Saharan Africa: Insights from field trials and literature review
- Journal Title
- Field Crops Research
DOI: https://doi.org/10.1016/j.fcr.2025.109932
For Inquiries
JIRCAS President: KOYAMA Osamu
- Program Director:
- FUJITA Yasunari
- Research Staff:
- ASAI Hidetoshi (Senior Researcher, Crop, Livestock and Environment Division)
- Press Coordinator:
- OMORI Keisuke (Head, Information and Public Relations Office)
Pree Email: koho-jircas@ml.affrc.go.jp
Terminology
- 1 Farmyard Manure/Compost
This organic fertilizer is made by composting livestock manure—such as from cattle, pigs, and chickens—together with plant residues like rice straw and grasses in the Poaceae family. Although it is widely used in rural areas, its degree of fermentation and nutrient composition vary greatly depending on the farmer who produces it.
- 2 Phosphorus Deficiency
In the highly weathered soils of Africa, not only is the total amount of phosphorus low, but much of it is strongly adsorbed by iron and aluminum, making it unavailable for crop uptake. As a result, plants are effectively in a state of phosphorus deficiency. According to a report by the Food and Agriculture Organization of the United Nations (FAO), about 70% of agricultural land in sub-Saharan Africa is affected by this phosphorus-deficient condition, which is considered a major factor limiting crop growth and reducing yields.