Agro-environmental studies on re-conciliating cropland expansion with nature conservation in sub-Saharan Africa

• Project/Area Number: 18H02314
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 41050:Environmental agriculture-related
• Research Institution: Kyoto University
• Principal Investigator: Araki Shigeru 京都大学, 地球環境学堂, 研究員 (00158734)
• Co-Investigator(Kenkyū-buntansha): 渡邉 哲弘 京都大学, 地球環境学堂, 准教授 (60456902) ; 真常 仁志 京都大学, 地球環境学堂, 准教授 (70359826) ; 柴田 誠 京都大学, 地球環境学堂, 助教 (40799607) ; 岡本 侑樹 京都大学, 地球環境学堂, 特定助教 (00635500)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥13,260,000 (Direct Cost: ¥10,200,000、Indirect Cost: ¥3,060,000); Fiscal Year 2020: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2019: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2018: ¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000)
• Keywords: 潜在可耕地 / サブサハラ・アフリカ / システム・ダイナミクス / 資源保護 / 農業開発 / サブサハラアフリカ / 自然保護 / 気候変動 / システムダイナミクス / 自然・資源保護

Outline of Final Research Achievements

The research was conducted to clarify the concept of "Potential arable land" to achieve the increased food production under limited available resources and environment. Based on field survey and analysis in rural areas of Cameroon, Malawi and Zambia, the status of crop field expansion, soil special characteristics of Oxisols and nutrient dynamics were clarified, and recommendations were made for future sustainable land management.
Significance of this research is justified by the fact that the idea of “Potential arable land“, which was so far remained within the field of agricultural sciences, extended its conceptual framework to the field of environmental and conservation sciences as negotiating tools that could provide sound basis for long-term sustainable resource management by local populations in the area of conflict between developers and conservationists.

Academic Significance and Societal Importance of the Research Achievements

従来、農業開発において用いられてきた潜在可耕地の概念を、より広い、地球環境保全、生物多様性、効果的な資源の投入の見地から再検討をくわえたことに学術的意義がある。アフリカの食料増産も、国別の農業案件ではなく、地球全体でのより公平な資源分配、国際的対策を必要としており、潜在可耕地の概念は、近未来の耕地拡大の是非を検討する有効な手法となる。更に、農業開発は、森林保護、国立公園の動物保護と対立しており、より説得的な住民主体の資源保全のツールとして応用していく道が開けた。

Research Products

• [Journal Article] Disentangling the pedogenic factors controlling active Al and Fe concentrations in soils of the Cameroon volcanic line (2023)
  • Author(s): Tetsuhiro Watanabe, Shiori Ueda, Atsushi Nakao, Antoine Mvondo Ze, Randy A. Dahlgren, Shinya Funakawa
  • Journal Title: Geoderma Volume: 430 Pages: 116289-116289
  • DOI: 10.1016/j.geoderma.2022.116289
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Investigating drivers of active nitrification in organic horizons of tropical forest soils (2023)
  • Author(s): Watanabe, S., Shibata, M., Kosugi, Y., Marryanna, L., Fukushima, K., Hartono, A., Funakawa, S.
  • Journal Title: Soil Ecology Letters Volume: 5(3) Issue: 3 Pages: 220167-220167
  • DOI: 10.1007/s42832-022-0167-x
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Distribution and dynamics of the Cynodon dactylon invasion to the cultivated fields of pearl millet in north-central Namibia (2022)
  • Author(s): Teshirogi Koki、Kanno Miho、Shinjo Hitoshi、Uchida Satoshi、Tanaka Ueru
  • Journal Title: Journal of Arid Environments Volume: 205 Pages: 104820-104820
  • DOI: 10.1016/j.jaridenv.2022.104820
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Quantitative relationship between organic carbon and geochemical properties in tropical surface and subsurface soils (2021)
  • Author(s): Ashida, K., Watanabe, T.*, Urayama, S., Hartono, A., Kilasara, M., Mvondo Ze, A. D., Nakao, A., Sugihara, S., Funakawa, S.
  • Journal Title: Biogeochemisry Volume: 155 Issue: 1 Pages: 77-95
  • DOI: 10.1007/s10533-021-00813-8
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Interactive effects of in-situ rainwater harvesting techniques and fertilizer sources on mitigation of soil moisture stress for sorghum (Sorghum bicolo (L.) Moench) in dryland areas of Tanzania (2018)
  • Author(s): Mahinda, A., Funakawa, S., Shinjo, H., Kilasara, M.
  • Journal Title: Soil Science and Plant Nutrition Volume: 64 Issue: 6 Pages: 710-718
  • DOI: 10.1080/00380768.2018.1525573
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Disentangling the pedogenic factors controlling active Al and Fe concentrations in soils of the Cameroon volcanic line (2023)
  • Author(s): Watanabe, T., Ueda, S., Nakao, A., Mvondo Ze, A., Dahlgren, R., Funakawa, S.
  • Organizer: 22nd World Congress of Soil Science
  • Int'l Joint Research
• [Presentation] pH, silicic acid activity, and weathering index link soil forming factors and clay mineral composition (2021)
  • Author(s): Watanabe, T., Lyu, H., Funakawa, S.
  • Organizer: ASA, CSSA, SSSA International Annual Meeting
  • Int'l Joint Research
• [Presentation] Agricultural practices and soil properties controlling crop production in sandy soils under semiarid tropical climate (2019)
  • Author(s): Shinjo, H. Kannno, M., Teshirogi, K., Nakashima, K., Tanaka, U. and Malima, B.
  • Organizer: 14th International Conference of the East and Southeast Asia Federation of Soil Science Societies
  • Int'l Joint Research
• [Presentation] Use of urine and excreta could improve vegetable production and soil fertility in central Nepal (2019)
  • Author(s): Sharda, KC and Shinjo, H.
  • Organizer: 14th International Conference of the East and Southeast Asia Federation of Soil Science Societies
  • Int'l Joint Research
• [Presentation] Soil properties controlling accumulation of C from plant residue (2019)
  • Author(s): Watanabe, T., Miyachi, A., Chen, Y-F, Zheng, J., Hartono, A., Pachikin, K., Funakawa, S.
  • Organizer: 14th International Conference of the East and Southeast Asia Federation of Soil Science Societies
  • Int'l Joint Research
• [Presentation] Distribution of soil organic carbon and its controlling factors in tropical volcanic regions (2019)
  • Author(s): Lyu, H., Watanabe, T., Hartono, A., Kilasara, M., Funakawa, S.
  • Organizer: 14th International Conference of the East and Southeast Asia Federation of Soil Science Societies
  • Int'l Joint Research
• [Presentation] Effects of active Al and Fe and degree of carbon saturation on organic matter accumulation (2019)
  • Author(s): Watanabe, T., Miyachi, A., Hartono, A., Funakawa, S.
  • Organizer: 14th International Conference of the East and Southeast Asia Federation of Soil Science Societies
  • Int'l Joint Research
• [Presentation] 土壌特性が植物残渣の分解と蓄積に与える影響 (2019)
  • Author(s): 渡邉哲弘, 宮地新, Yu-Fang Chen, Jinsen Zheng, Arief Hartono, Konstantin Pachikin, 舟川晋也
  • Organizer: 日本土壌肥料学会2019年度静岡大会, 於：静岡大学,静岡
• [Presentation] Formation processes and properties of soils in central and northern Malwi (2019)
  • Author(s): Chisambi, C. and Shinjo, H.
  • Organizer: 日本熱帯農業学会第125回講演会
• [Presentation] Weathering sequence of clay-size minerals based on wethering index and silicic acid activity (2018)
  • Author(s): Watanabe, T., Lyu, H. and Funakawa, S.
  • Organizer: 21st World Congress of Soil Science at Rio de Janeiro, Brazil
  • Int'l Joint Research
• [Presentation] Factors controlling organic carbon storage in tropical soils (2018)
  • Author(s): Ashida, K., Watanabe, T., Hartono, A., Kilasra, M., Mondo Ze, A. and Funakawa, S.
  • Organizer: 21st World Congress of Soil Science at Rio de Janeiro, Brazil
  • Int'l Joint Research
• [Presentation] How can we mitigate impact of climatic variability on crop production in the semiarid tropics of Africa ? (2018)
  • Author(s): Shinjo, H., Ando, K., Nakashima, K., Umetsu, C., Tanaka, U., Sokotela, S. and Malima, B.
  • Organizer: 21st World Congress of Soil Science at Rio de Janeiro, Brazil
  • Int'l Joint Research
• [Book] 「第２章 植生と土壌」『ザンビアを知るための５８章』（ 島田周平・大山修一 編） (2020)
  • Author(s): 真常仁志・荒木茂
  • Publisher: 明石書店
• [Book] 熱帯土壌の種類と分布（江原宏、樋口浩和（編）『熱帯農学概論』） (2019)
  • Author(s): 真常仁志
  • Publisher: 培風館
• [Book] 古土壌（木村眞人、南條正巳（編）『土壌サイエンス入門第2版』） (2018)
  • Author(s): 荒木 茂
  • Publisher: 文永堂出版