African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6574

Full Length Research Paper

Water and nutrient balances under selected soil and water conservation practices in semi-arid Ruzizi plain, Eastern Democratic Republic of Congo

Espoir M. Bagula
  • Espoir M. Bagula
  • Faculty of Agriculture and Environmental Sciences, Université Evangélique en Afrique, Bukavu, Democratic Republic of Congo.
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Jackson G. M. Majaliwa
  • Jackson G. M. Majaliwa
  • College of Agriculture and Environmental Sciences, Makerere University, Kampala, Uganda.
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Gustave N. Mushagalusa
  • Gustave N. Mushagalusa
  • Faculty of Agriculture and Environmental Sciences, Université Evangélique en Afrique, Bukavu, Democratic Republic of Congo.
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Twaha A. Basamba
  • Twaha A. Basamba
  • College of Agriculture and Environmental Sciences, Makerere University, Kampala, Uganda.
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John Baptist Tumuhairwe
  • John Baptist Tumuhairwe
  • College of Agriculture and Environmental Sciences, Makerere University, Kampala, Uganda.
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Sarah Akello
  • Sarah Akello
  • College of Agriculture and Environmental Sciences, Makerere University, Kampala, Uganda.
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Jean-Gomez M. Mondo
  • Jean-Gomez M. Mondo
  • Faculty of Agriculture and Environmental Sciences, Université Evangélique en Afrique, Bukavu, Democratic Republic of Congo.
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Geofrey Gabiri
  • Geofrey Gabiri
  • Department Geography and Social Studies, Faculty of Arts and Social Sciences, Kyambogo University, Kampala Uganda.
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Patrick Musinguzi
  • Patrick Musinguzi
  • College of Agriculture and Environmental Sciences, Makerere University, Kampala, Uganda.
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Cephas B. Mwimangire
  • Cephas B. Mwimangire
  • Faculty of Agriculture and Environmental Sciences, Université Evangélique en Afrique, Bukavu, Democratic Republic of Congo.
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Moses M. Tenywa
  • Moses M. Tenywa
  • College of Agriculture and Environmental Sciences, Makerere University, Kampala, Uganda.
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  •  Received: 11 July 2021
  •  Accepted: 06 October 2021
  •  Published: 30 November 2021

Abstract

Soil water deficit is a major production-limiting factor in the predominantly rainfed agriculture of the Ruzizi plain, eastern Democratic Republic of Congo (DRC). Appropriate soil and water conservation (SWC) practices would be a valuable option for maximizing water uptake by plants in the context of water demand and supply unbalance. This study assessed the efficiency of selected SWC practices in improving water and nutrient (nitrogen and phosphorus) balances along the slope gradients in Ruzizi plain using a three-season field experiment. The SWC practices, tied ridges and Zaï pits, improved the cumulative soil water balance by 148.7 and 21.1%, respectively, compared to conventional tillage. In the same order, the maize (Zea mays L.) yield performance significantly varied with SWC practices: tied ridges (2.16 t ha-1) out performed the Zaï pits (1.48 t ha-1) and conventional tillage (1.58 t ha-1).  Besides, the tied ridges reduced the total nitrogen losses by 34.4–49.8%, compared to conventional tillage. However, SWC practices were only reliable when daily rainfall amounts were at reasonable threshold (>10 mm) and on low slope gradients (<8%). Therefore, tied ridges provide an opportunity as a component of an integrated soil water and nutrient management strategy to sustain the rainfed maize production in Ruzizi plain.

Key words: Tied ridges, Zaï pits, rainfall variability, slope gradient, dryland, Zea mays L.