PEDRO LUIZ TERRA LIMA ASSESSING WATER EROSION IN DIFFERENT LAND USES BY MAGNETIC TRACERS LAVRAS - MG 2016 PEDRO LUIZ TERRA LIMA ASSESSING WATER EROSION IN DIFFERENT LAND USES BY MAGNETIC TRACERS Thesis submitted for the degree of Doctor of Philosophy as a Dual PhD with Ciência do Solo Postgraduate Program, Universidade Federal de Lavras, Brazil and Lancaster Environment Centre, Lancaster University, United Kingdom. Supervisors Dr. Marx Leandro Naves Silva (UFLA) Dr. John Quinton (Lancaster University) Dr. Barbara Maher (Lancaster University) LAVRAS - MG 2015 Ficha catalográfica elaborada pelo Sistema de Geração de Ficha Catalográfica da Biblioteca Universitária da UFLA, com dados informados pelo(a) próprio(a) autor(a). Lima, Pedro Luiz Terra. Assessing water erosion in different land uses by magnetic tracers / Pedro Luiz Terra Lima. – Lavras : UFLA, 2016. 170 p. : il. Tese(doutorado)–Universidade Federal de Lavras, 2015. Orientador(a): Marx Leandro Naves Silva. Bibliografia. 1. Environmental magnetism. 2. Fingerprinting. 3. Sediments. 4. Tropical soils. 5. Water erosion. I. Universidade Federal de Lavras. II. Título. PEDRO LUIZ TERRA LIMA PEDRO LUIZ TERRA LIMA ASSESSING WATER EROSION IN DIFFERENT LAND USES BY MAGNETIC TRACERS Thesis submitted for the degree of Doctor of Philosophy as a Dual PhD with Ciência do Solo Postgraduate Program, Universidade Federal de Lavras, Brazil and Lancaster Environment Centre, Lancaster University, United Kingdom. APROVED in 14 of December, 2015. Dr. Marx Leandro Naves Silva UFLA Dr. John Quinton Lancaster University Dr. Nilton Curi UFLA Dra. Angela Dayana Barrera de Brito UFLA Dr. Phil Haygarth Lancaster University Dr. Wenceslau Geraldes Teixeira EMBRAPA Solos LAVRAS – MG 2015 DECLARATION I hereby declare that this work has been originally produced by myself for this thesis and it has not been submitted for the award of a higher degree to any other institution. Collaborations with other researchers, as well as publications or submissions for publication are properly acknowledged throughout the document. Pedro Luiz Terra Lima, Lavras, December 2015. Dedico esta tese a Deus. I DEDICATE ACKNOWLEDGEMENTS I would like to take this opportunity to first and foremost thank God for being my strength and guide in the writing of this thesis. I would like to express my eternal gratitude to my “supervisor team”: Marx Silva, John Quinton, Barbara Maher, Nilton Curi and Alona Armstrong. Thank you very much for your guidance, teachings and support!! Besides my supervisors, I would like to thank my viva committee: Angela Brito, Phil Haygart, Wenceslau Teixeira, Humberto Rocha and Nick Ostle for their encouragement and insightful comments. A deep respect and gratitude to ones that made this happen, the ones that gave me strengths, patience and bravery to finish this task: my parents Luiz and Mariana (we did it!), Júlia (cheers for UK great time) and João, my love Maísa (conseguimos minha rainha!), and all my family, specially Dona Licinha, José Maria and Andréia!!! A special thanks for friends Betania Mansur, Carlinhos Ribeiro, Damy Pádua, Dirce Macedo, Téo de Abreu, Dulce Moraes, Jean Arantes, Maria Alice, Milton Arantes, Teotônio Soares, José Roberto Pezão and Negão from UFLA, as well as Vassil Karloukovski, Sam Harris and Gareth McShane from Lancaster University, for all their help, hard work and full availability when I most needed. Also, my sincere thanks to people at UFLA: Gabriel Carvalho, Renzo Von Pinho, Luiz Gonzaga, Carlos Silva, Fátima Moreira, Geraldo Oliveira, João José, Luiz Bebeto, Michele Menezes, Moacir Dias, Mozart Ferreira, Valdemar Faquin, Vicente Gualberto, Yuri Zinn, Adalberto Ferreira, Cristina Ribeiro, Geila Carvalho, Gilson Fernandes, Humberto Fernandes, João Gualberto, Marcio Marques, Regina Lasmar, Roberto Mesquita, José Luis e Neném; at Lancaster University: Jos Barlow (thanks for the help and opportunity), Luke Parry, Jackie Pates and Andy Harrod; and UFRGS’s Alberto Inda Júnior for all the support and help through all those years. I thank my fellow labmates and friends in for the stimulating discussions and for all the fun we have had in the last four years: Mateus Naza, Pedro Jipa, Leandro Campos, Bernardo Nino, Tio Zumba, Tio Lucas, Fábio José, Barbara, Diego França, Dany Guim, Fabio Arnaldo, Adnane, Dani Boy, Tom, Endrew, Wharley, Fabinho Pereira, Rodrigo Diguinho, Thais Palumbo, Karine, Jéssica, Fani, Michael Thebaldi, Mateus Vô, Rafael Baiano, Marcelo Bin, Vinicius Zina, Cazuza, Matheus Caroço, Willian Jacaré, Rafa Gatto, Fagner Badalo, Glaúcio, Fábio Pociano, Gabriel Araujo, Murilo Machado, Lucas Abreu, Betão, Anderson Robsón, João, Regi Coelho, Igor Gods, Giovanna, Raphael Siqueira, Sérgio Henrique, Guilherme Dinali, Davi, Cristiano, Romulo Alexandrino, Romulo Duarte, Bruno Montoani, Cléber Rodas, Zélio, Silas, Élen Alvarenga, Lili, Ines, Diego Capado, Eliete, Fábio Bispo, Francisco Hélcio, Gabriel Caixeta, Henrique Maluf, Luana, Maíra, Samara and Wantuir. A special thanks to the Lancaster “family” for the friendship and support: Toru and Lisi, Rob and Beth, Andrezão, Sifah, Jack, Vito, Ciça and Al, Arlete and Caio, Antonio Capponi, Filipe, Lucas Gent, Amy Valach, Wallace and Ananza, Mari, Ruanny, Arthur, Natalie, Dany, Hannah, Anne, Ceri, Artzai and Ainara; and the Brazilians/British, Bruno and Marcela, Alexandre, Alcides Perón, Bruno Cafeo, Iago, André Moraes, Natalia, Bruno Sanderberg, Carol, Júlia, Lucas, Lilia, Beto, Kamilo, Douglas and Juliano. Thanks to roommates and truly friends from Lancaster: Antonis, Leticia, Shuang and Bo, Petr and Victoria. It was great guys. Thanks for everyone that somehow made this work possible!! Finally, I also recognize my gratitude to CAPES (Coordination of Improvement of Higher Education Personnel – Process number 12082/13-9), FAPEMIG (Research Foundation of Minas Gerais State) and CNPq (National Research and Development Council – Process number 143437/2011-9 and 167089/2014-5) for their financial support and scholarships. “The nation that destroys its soil, destroys itself.” Franklin D. Roosevelt ABSTRACT This research was carried out to investigate water erosion in a tropical site (Lavras, Minas Gerais state, Brazil) accessing soil and water losses, measuring magnetic properties of different soil classes and particle sizes, as well as characterizing deposited sediments collected at bottom of downstream reservoirs. As described in article 1, rainfall erosivity and soil and water losses in standard plots were evaluated subject to different cultivation systems. Results observed lead to the conclusion that initial plant development must be intense and fast in order to protect the soil surface and prevent water erosion. Rather than using only traditional procedures for erosion evaluations, this research employed more sophisticated techniques such as magnetic environmental fingerprinting to better understand tropical soil erosion (Article 2). Magnetic properties varied according to soil classes and soil particle size. Results obtained revealed that tropical soils are mainly magnetically influenced by parent material, relief, internal profile drainage and landscape position. Their relationships were specifically linked to ferrimagnetic clay minerals. After detecting these differences, it investigated the magnetism of reservoirs sediments with purpose to associate it to different soil classes and possibly identify the sediment sources (Article 3). Pioneer in tropical soils, this research employed magnetic fingerprinting techniques to successfully find the origin of the deposited sediments, turning possible even to quantify the proportion that were originated from one or other soil class. The proposed procedure can be considered by researchers to better understand soil particle transport by erosion and find their origin. Keywords: Environmental magnetism. Fingerprinting. Sediments. Tropical soils. Water erosion. RESUMO A presente pesquisa foi realizada com o intuito de investigar a erosão hídrica em uma área tropical (Lavras, Minas Gerias, Brasil) através de perdas de solo e água, mensurando propriedades magnéticas em diferentes classes de solos e partículas de solo, assim como pela caracterização de sedimentos depositados coletados no fundo de reservatórios. Como descrito no artigo 1, a erosividade da chuva e as perdas de solo e água em parcelas padrão foram avaliadas em diferentes sistemas de cultivo. Resultados observados permitiram concluir que o desenvolvimento inicial das plantas deve ser intenso e rápido com o intuito de proteger a superfície do solo e prevenir a erosão hídrica. Ao invés de utilizar apenas metodologias tradicionais para avaliações do processo erosivo, a presente pesquisa utilizou técnicas mais sofisticadas como ‘fingerprinting’ ambiental magnético para melhor entender erosão em solos tropicais (Artigo 2). As propriedades magnéticas variaram quanto às classes de solo e tamanhos das partículas do solo. Resultados obtidos revelaram que solos tropicais são predominantemente influenciados magneticamente pelo material de origem, relevo, perfil de drenagem interno e posição na paisagem. As relações foram especificadamente relacionadas com os argilominerais ferrimagnéticos. Após detectar tais diferenças, a investigação do magnetismo de sedimentos de reservatórios foi realizada com objetivo de associa-los com os diferentes solos e possivelmente identificar as fontes de sedimentos (Artigo 3). Pioneiramente em solos tropicais, a presente pesquisa aplicou técnicas de ‘fingerprinting’ magnético para com sucesso encontrar a