GENERAL INFORMATION
| ISSN: 2429-5396 (e) | www.american-jiras.com | |
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| ARTICLE | Am. J. innov. res. appl. sci. Volume 13, Issue 4, Pages 438-445 (October, 2021) |
Research Article 3 |
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| OCTOBER | VOLUME 13 | N°4 | 2021 |
| Info-AJIRAS-® Journal ISSN 2429-5396 (Online) / Reference CIF/15/0289M |
American Journal of Innovative Research & Applied Sciences
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American Journal of innovative
Research & Applied Sciences
ISSN 2429-5396 (Online)
OCLC Number: 920041286
Authors Contact
*Correspondant author and authors Copyright © 2021:
| Fanjanirina Rovatiana Randrianantenaina 1*| Martin Rasolonirina 1|Asivelo Fanantenansoa Solonjara 1 | and | Naivo Rabesiranana 1,2 |
Affiliation.
1.Institut National des Sciences et Techniques Nucléaires (INSTN-Madagascar) | Antananarivo | Madagascar |
2. University of Antananarivo | Faculty of Sciences | Antananarivo | Madagascar |
This article is made freely available as part of this journal's Open Access: ID | Randrianantenaina–Ref1-ajira270921 |
*Corresponding author Author & Copyright Author © 2021: | Fanjanirina Rovatiana Randrianantenaina 1* |. All Rights Reserved. All articles published in American Journal of Innovative Research and Applied Sciences
are the property of Atlantic Center Research Sciences, and is protected by copyright laws CC-BY. See: http://creativecommons.org/licenses/by-nc/4.0/.
ABSTRACT
Background: Soil erosion is an observable phenomenon of Madagascar Highland. Soil deposition affects upstream cultivated land and downstream waterway silting. Objectives: To support and guide mitigation strategies related to agricultural practices, it is necessary to assess the factors involved and influencing the variability of the soil erosion magnitude. Methods: Sloped cultivated site at Andranomanelatra Antsirabe, central Madagascar was selected as a study site. Two field work campaigns were carried out: in December 2018 at the beginning of rainy season and in March 2020 at the end of rainy season. Beryllium-7 (7Be) atmospheric fallout radionuclide technique has been used to determine the impact of short-term rainfall events (< 6 months). 7Be activities in soil samples were measured through the 477.6 keV gamma ray peak, using a HPGe gamma spectrometry system. To convert inventory (Bq.m-2) to erosion rate (t.ha-1), Profile Distribution Model (PDM) was used. Subsequently, statistical multivariate analysis was performed for data treatment to investigate effects of factors involved. Results: Considering the site as a whole, net soil erosion is estimated to 2.88 t.ha-1 and 7.55 t.ha-1 during 1st and 2nd field work respectively. The value obtained during 2nd fieldwork, which is twice that of the first one, can be explained by the five following factors. High quantity and frequency of rainfall increase soil erosion rate. Longer plot reduces sediment delivery ratio. Soil loss from the upper plot is deposited on the lower plot. Plant with dense cover (maize) reduces soil erosion, whereas plant with low cover (cassava) increases it. Low micro-slope retains soil movement and steep micro-slope increases it. Soil erosion dominates in the upper part of the slope and soil deposition in the lower part. Conclusions: The results obtained confirm the 7Be technique potentiality to determine soil erosion and its causes during a short period of rainfall. In order to minimize erosion factor effects, it is advisable to plant crops with dense cover, otherwise to combine the crops with weak and dense cover. Cultivation in flat site is proposed. In case of sloped terrain, transformation into terrace reduces soil erosion. Finally, cultivated area should be long in order to reduce runoff velocity and to retain sediment.
Keywords: Madagascar, erosion, beryllium-7, spectrometry, model, factor
SOIL EROSION FACTOR ASSESSMENT ON CULTIVATED SITE OF MADAGASCAR HIGHLAND BY THE 7Be TECHNIQUE AND MULTIVARIATE ANALYSIS
| Fanjanirina Rovatiana Randrianantenaina 1*| Martin Rasolonirina 1|Asivelo Fanantenansoa Solonjara 1 | and | Naivo Rabesiranana 1,2 |. Am. J. innov. res. appl. sci. 2021; 13(4):438-445.
| PDF FULL TEXT | | XML FILE | | Received | September 26, 2021 | | Accepted | October 02, 2021 | | Published | October 05, 2021 |