COMMUNAUTÉ FRANÇAISE DE BELGIQUE UNIVERSITÉ DE LIÈGE – GEMBLOUX AGRO-BIO TECH Towards a regional soil reference system for fertility assessment and monitoring in the highlands of Mindanao, Philippines Guadalupe M. DEJARME-CALALANG Dissertation originale présentée en vue de l’obtention du grade de Docteur en Sciences Agronomiques et Ingénierie Biologique Promoteurs: Laurent Bock Gilles Colinet Année civile 2015 To RODOLFO, my husband and my sons, JANSSEN and JAMES CONRAD, this work is dedicated. ii Acknowledgment I am truly grateful to all, who in one way or another have supported me in this challenging work. To the Cooperation of Universities for Development (CUD) for the scholarship grant, To Xavier University, Philippines, for the study leave grant and research support through its Faculty Development Program. To Prof Laurent Bock, my PhD Promoteur, to whom I deeply acknowledge, for unselfishly imparting to me his knowledge in Soil Science through his utmost guidance in the over-all PhD research, and his incessant encouragement that get me through in this intellectually and physically demanding work, To Prof Gilles Colinet, Co-Promoteur for assisting me in the data gathering, who painstakingly had checked the pot experiment part of the manuscript, and for his guidance on the statistical analyses, To the five MSc students who worked with me in this CUD project and shared to me their gathered information, Lola Richelle, Fanny Lebrun, Sophie Barbieux, Sophie Van Daele of Universite de Liege-Gembloux Agro Bio Tech (ULg-GxABT), and Simon Maurissen of Universite Libre de Brussels, To the members of the PhD Committee; Prof Aurore Degre of ULg-GxABT and Prof Vincent Hallet of Universite de Namur for their assistance in the data gathering, Prof Philippe Lebailly and Prof Guy Mergeai of ULg-GxABT, Prof Joseph Dufey and Prof Sophie Opfergelt of Universite Catholique de Louvain for their valuable comments and suggestions to improve the study and PhD manuscript, and to Dr. Valerie Genot, for the NIRS analysis of the soil samples, I sincerely am thankful to the two farming communities, Miarayon and Bendum for the friendship and safety during the field work, I deeply acknowledge the help of Barangay Captain Robert Sulatan and Lanie Sulatan who assisted me in organizing the fieldwork in Miarayon, for without them, it would be difficult for me to infiltrate the area, to Sr Jessica Gemino and the Missionary Sisters of the Sacro Costato, Mateo Sanchez SJ and Miriam Layucan of the St Therese of the Child Jesus Parish, Noel and Nenet Hanginan for accommodating us during the field work, the farmers and their families who collaborated with me in the work, Corsino Buling and family, Roel Buling and family, Dodong and Zelda Flores, Jermie Angel, Virginio Sulod, the late Florito Bagas and his family, Nerio Salino, Ranilo Lajero and family, Hermilito Angel, Jerson Angel, Myrna and Zeke Sanghid, Sergio Hinganan, Roberto Memper, Eugenio Lagayon, Adogar Member, Felix de la Cerna, Mariano and Virginia Sulatan, Lucio Laguilay, the late Enerio Hinganan and his sons, to those who had provided the muscles during the augering and pit digging, Bernardo Sulatan, Jake Memper, Patrino Inta, Jick and Jig Sulatan, Albert Memper, Johnny and Jay Sulatan and Hernan Palma. To the Bendum Community; the farmers who collaborated with me in the Bendum work, Julie Menaling, Nestor Menaling, Hipolito and Joy Buaya, Myrna Berdisula, Julie Gallamaso, Man Dagnayan, Norberto Navas, Berto Banahan, Dole Deloso, Danny Bono, Genara Hewe, to those who assisted us in pit digging and soil sampling Anecito Santer, Rufino Sagula, Jessie Berdisula, Nilo Almahan, Jason Menaling and to the pupils of Apo Palamguwan Cultural Education Center who always had accompanied us to the field. iii To the Soil Science Unit Staff of ULg-GxABT, to Raphael Tarantino for all his assistance given, from administrative organizations to computer concerns, Amandine Lienard for constantly checking with me my ECTS requirements, to Beatrice Lagrange and Malorie Renneson for the logistical support and to Francoise Toussant for the plant and soil analyses. To the Environmental Science for Social Change (ESSC); Andres Ignacio and to the very supportive ESSC staff Arnel Santander, Eric “Popoy” Bruno, Cherie Domer, Freida Tabuena, Leanne Fernandez, Ceasar Aguinaldo, Ariel Amor, Jenifer Ogaña, Eddie Campos, Aili Gatuslao, Joan Jamisolamin and Robelito Buntas. To Xavier University colleagues: to Dr Lina Kwong, Mark Alexis Sabines and Alexis Maristaza of the Agricultural Engineering Department, to Glenda Orlanes and Reynaldo Antonio Mante of the College of Agriculture-Assistant Dean’s Office, Bern Geveso and Virgie Bulang of the Office of the President for the various assistance, to Lorna Picar and Richel Malon of the Central Purchasing Unit for facilitating the purchase of the Isuzu Fuego and spare parts, to Ramil Pajo and Noemi Dacudao of the Physical Plant Office, for the conversion of a space into a Soil Laboratory, to Jofferdale Gallamaso for the laboratory design, to Franciso Umaran for setting-up the internet connection in the laboratory and its maintenance, and to Madame Elisabeth Enerio of the Office of International Cooperation and Networking, for her assistance in my difficulties of the French language. To Hernando Pacana and the Manresa Experimental Research Station workforce of Xavier University, Aldwin Palanas, Allan Ranis, Boeding Mingoc, Nestor Diango, Samuel Libot and Arnold Casil for facilitating the work, from the construction of the pot experiment shed, the driving services provided during field work, the maintenance of the soil laboratory and of the field work vehicle, to the Manresa Security Unit for the safety provided during the numerous overnight-stays in the Soil Laboratory because of the PhD manuscript preparation. I truly appreciate Prof Françoise Orban and her family for they are my family in Belgium. I am grateful for the welcoming and generosity of Madame Jennifer Bock and her family, from the weekend dinners, the transport facilitated from and to Brussels airport, to the provisions of home effects for my apartment, to Madame Françoise Descamp, Monsieur Thierry Henckaerts and Madame Alix Raway for always providing me a place in Maison Nord Sud, my home in Gembloux. To the Jesuit fathers; Jose Ramon T Villarin SJ and Peter W Walpole SJ, for whom through them I was able to find the PhD grant, and to Roberto C Yap SJ for continuing the support until the end of my PhD study. Thank you. Guadalupe M. Dejarme-Calalang iv Abstract This PhD research work is a contribution to the umbrella research project in Mindanao, Philippines entitled “Establishing strategic partnership in research to strengthen local governance in land and water management for greater human security in Mindanao (EPaM)” which was supported by the Cooperation of Universities for Development - Inter University Program (CUD-PIC) of Belgium with the long term objective to capacitate local entities in managing land and water resources in their jurisdiction. As part of the CUD-PIC project, the research has two objectives: (1) the establishment of a Soil Reference System (SRS) to respond to the needs of soil information for scientific bases in land use planning and agricultural development at the local level, and (2) the use of this established SRS as a pertinent tool for agricultural extension services to local farmers on soil management and crop production. The specific study locations were Miarayon, Talakag and Bendum, Malaybalay City of the Bukidnon Province. The study had four sub components: (i) the geomorphopedological identification of potentialities and constraints, (ii) the soil fertility assessment with predominant crop yields to initiate a SRS as bases for monitoring in the future, (iii) the soil fertility assessment and calibrating using a test plant in a pot experiment, and (iv) the information integration of the SRS for highland areas in Mindanao, Bukidnon. Miarayon and Bendum soils are both derived from volcanic parent materials, but their development differs by duration and rock origin. Bendum soils are derived from ultramafic rocks in the periods of Upper Cretaceous and Paleogene and Oligocene Lower Miocene while Miarayon soils originated from pyroclastic rocks of the Pliocene-Quaternary period. Dominance of total elements in soils of both areas is due to either natural causes or anthropogenic activities. The dominance of Mg in Bendum rocks is effectively due to its ultramafic parent rock materials while in Miarayon the prevalence of Ca is due to the application of chicken dung in which chicken feed formulas have Ca additives. Moreover Miarayon soils have in general higher organic matter content and more available nutrients v than Bendum soils. The encroachment of cultivation on the steep slopes in both areas indicates the high demand of lands for production in the highlands. Crops in Miarayon which are intended for the market are short term, such as vegetables, with a growing season of three to four months. Bendum crops that are for the market are perennial ones such as rubber and coffee and therefore are long term crops, and abaca which are for fiber materials. Food crop in Miarayon is corn while in Bendum is corn and sweet potato. Crop yields are indicators of soil fertility and crop management in a given prevailing climate. In Miarayon soils, there is a good relationship between the yields of potato and TOC, TN, Ca and Mg. There is also a good relationship between yields of corn and Ca and Mg. The robustness of relationships is shown in spite of few observations. A pot experiment was carried out to test the response of a plant to different soil types. Results on plant nutrient analyses had shown the transfer of elements, from parent rock materials, to soil formation and until the nutrient absorption by the test plant. Results had corroborated the findings in literature researches about which nutrients are prevalently assimilated by test plants. The methodology used in this SRS shall serve as template for instruction and research on soils in Mindanao.