Evaluation of cultivation management of main crops in North-central Namibia utilizing non-destructive measurements

• Project/Area Number: 18K14454
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 39020:Crop production science-related
• Research Institution: Kindai University
• Principal Investigator: Hirooka Yoshihiro 近畿大学, 農学部, 講師 (80780981)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2020: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2018: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: パールミレット / 非破壊計測 / LAI / ナミビア / 混作 / 季節性湿地 / 半乾燥地 / 気候変動 / トウジンビエ / 施肥管理 / 季節湿地 / 耕うん / 葉面積指数 / 水環境 / 栽培技術 / 化学肥料 / 牛糞 / 接触混植 / アイスプラント / 湛水ストレス / 施肥 / 栽培管理 / 栄養環境

Outline of Final Research Achievements

Although north-central Namibia is a semi-arid land, heavy rains and floods cause soil moisture stress to drought-tolerant crops. The objective of the present study is to evaluate the effect of cultivation management on the growth and yield of pearl millet under different water environments. The result showed that interactions between the water environment and the fertilization method significantly affect the yield of pearl millet and that the optimum fertilization method differs depending on the rainfall patterns. A method has been developed for estimating the yield of pearl millet using continuous and non-destructive measurement to determine the leaf area index. It has revealed that the introduction of mixed cropping of pearl millet and rice into seasonal wetlands is economically benefical.

Academic Significance and Societal Importance of the Research Achievements

季節性湿地におけるパールミレットの収量は主に総乾物重によって決定されており，穂数と密接に関連していることがわかった．したがって，最適な栽培管理を実現するには，栄養成長期における継続的な生育診断に基づいた追肥の施用が効果的であると考えられた．そのため，非破壊計測による経時的な葉面積指数モニタリングを利用することによって生産性を改善できる可能性を示したことに学術的意義がある．さらに，実際の農家の収量調査とインタビュー調査を行うことで，季節性湿地における作物の生産性を経済的に解析したことも大きな社会的意義があると考えられる．

Research Products

• [Int'l Joint Research] ナミビア大学(ナミビア)
• [Int'l Joint Research] ナミビア大学(ナミビア)
• [Int'l Joint Research] ナミビア大学(ナミビア)
• [Journal Article] Agronomic and Socio-economic Assessment of the Introduction of a Rice-Based Mixed Cropping System to Cuvelai Seasonal Wetland System in Northern Namibia (2021)
  • Author(s): Hirooka Y, Masuda T, Watanabe Y, Izumi Y, Inai H, Awala S.K, Iijima M
  • Journal Title: Agrekon Volume: 60 Issue: 2 Pages: 1-10
  • DOI: 10.1080/03031853.2021.1917429
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Growth and Productivity Assessment of Short-Duration Rice (Oryza sativa L. and Upland NERICA) Genotypes in Semiarid North-Central Namibia (2021)
  • Author(s): Simon K. Awala , Kudakwashe Hove, Vistorina Shivute, Johanna S. Valombola, Pamwenafye I. Nanhapo, Yoshihiro Hirooka, Osmund D. Mwandemele and Morio Iijima
  • Journal Title: Advances in Agriculture Volume: 2021 Pages: 1-10
  • DOI: 10.1155/2021/6676081
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Ridge formation with strip tillage alleviates excess moisture stress for drought-tolerant crops (2019)
  • Author(s): Hirooka Yoshihiro、Shoji Koichi、Watanabe Yoshinori、Izumi Yasuhiro、Awala Simon K.、Iijima Morio
  • Journal Title: Soil and Tillage Research Volume: 195 Pages: 104429-104429
  • DOI: 10.1016/j.still.2019.104429
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Effects of Ridging and Fertilizer Application on Crop Yield and Growth under Unstable Water Environments (2021)
  • Author(s): Hirooka Y, Awala SK, Nanhapo PI, Shoji K, Watanabe Y, Izumi Y, Iijima M.
  • Organizer: ACSAC10
  • Int'l Joint Research
• [Presentation] イネとアイスプラントの接触混植による塩と湛水の複合ストレス緩和効果 (2020)
  • Author(s): 春名啓介, 山根浩二, 廣岡義博, Nanhapo Pamwenafye I., 飯嶋盛雄
  • Organizer: 第249回日本作物学会講演会
• [Presentation] 亀裂施肥によるダイズの湿害緩和の要因解明 (2020)
  • Author(s): 須浪章裕, 廣岡義博, 山根浩二, 飯嶋盛雄
  • Organizer: 第249回日本作物学会講演会
• [Presentation] ダイズ/イネ接触混植におけるイネの適正個体数 (2019)
  • Author(s): 米谷拓朗, 廣岡義博, 山根浩二, 飯嶋盛雄
  • Organizer: 第248回日本作物学会講演会
• [Presentation] 耕うん・施肥方法がナミビア北部におけるトウジンビエの生育および収量に与える影響 (2019)
  • Author(s): 廣岡義博・Simon K. Awala・Kudakwashe Hove・Pamwenafye I. Nanhapo・飯嶋盛雄
  • Organizer: 第247回日本作物学会
• [Presentation] Close mixed-planting enhances both flood- and drought- tolerance of upland crops and rice (2018)
  • Author(s): Iijima M, Yamane K, Hirooka Y.
  • Organizer: 3rd International conference on Agricultural and Food Science
  • Int'l Joint Research
• [Presentation] A study on the effect of fertilizer application on growth and yield components of pearl millet (Pennisetum glaucum L.) subjected to field flooding (2018)
  • Author(s): Hailemo RWN, Awala SK, Hirooka Y, Nanhapo PI, Iijima M.
  • Organizer: 2nd International Conference on Agriculture and Natural Resources Research and Innovation
  • Int'l Joint Research
• [Presentation] 接触混植はイネの塩ストレスとアイスプラントの湛水ストレスの両者とも緩和した (2018)
  • Author(s): 春名 啓介, 山根 浩二, 廣岡 義博, 飯嶋 盛雄
  • Organizer: 第246回日本作物学会