title: Assessment of soil redistribution rates by (137)Cs and (210)Pbex in a typical Malagasy agricultural field.
abstract: Soil degradation processes affect more than one-third of the Malagasy territory and are considered as the major environmental threat impacting the natural resources of the island. This innovative study reports about a pioneer test and use of radio-isotopic techniques (i.e. Cs-137 and Pb-210ex) under Madagascar agroclimatic condition to evaluate soil erosion magnitude. This preliminary investigation has been conducted in a small agricultural field situated in the eastern central highland of Madagascar, 40 km East from Antananarivo. Both anthropogenic Cs-137 and geogenic Pb-210 soil tracers provided similar results highlighting soil erosion rates reaching locally 18 t ha(-1) yr(-1,) a level almost two times higher than the sustainable soil loss rate under Madagascar agroclimatic condition. The sediment delivery ratio established with both radiotracers was above 80% indicating that most of the mobilized sediment exits the field. Assessing soil erosion rate through fallout radionuclides in Madagascar is a first step towards an efficient land and water resource management policy to optimise the effectiveness of future agricultural soil conservation practices.
authors.affiliation: Institut National des Sciences et Techniques Nucléaires (INSTN - Madagascar), BP 4279, Antananarivo, 101, Madagascar. Electronic address: instn@moov.mg.
authors.forename: N
authors.initials: N
authors.lastname: Rabesiranana
authors.affiliation: Institut National des Sciences et Techniques Nucléaires (INSTN - Madagascar), BP 4279, Antananarivo, 101, Madagascar.
authors.forename: M
authors.initials: M
authors.lastname: Rasolonirina
authors.affiliation: Institut National des Sciences et Techniques Nucléaires (INSTN - Madagascar), BP 4279, Antananarivo, 101, Madagascar.
authors.forename: A F
authors.initials: AF
authors.lastname: Solonjara
authors.affiliation: Institut National des Sciences et Techniques Nucléaires (INSTN - Madagascar), BP 4279, Antananarivo, 101, Madagascar.
authors.forename: H N
authors.initials: HN
authors.lastname: Ravoson
authors.affiliation: Institut National des Sciences et Techniques Nucléaires (INSTN - Madagascar), BP 4279, Antananarivo, 101, Madagascar.
authors.lastname: Raoelina Andriambololona
authors.affiliation: Soil and Water Management & Crop Nutrition Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria.
authors.forename: L
authors.initials: L
authors.lastname: Mabit
mesh_terms: D000383:Agriculture; D002588:Cesium Radioisotopes / Q000032:analysis*; D003247:Conservation of Natural Resources / Q000379:methods*; D019015:Geologic Sediments / Q000032:analysis; D007856:Lead Radioisotopes / Q000032:analysis*; D008270:Madagascar; D011834:Radiation Monitoring; D012987:Soil / Q000737:chemistry; D012990:Soil Pollutants, Radioactive / Q000032:analysis*
chemical_list: D002588:Cesium Radioisotopes; D007856:Lead Radioisotopes; D012987:Soil; D012990:Soil Pollutants, Radioactive
keywords: Ceasium-137; Erosion; Madagascar; Pb-210; Soil