An investigation of sugarcane nitrogen physiology: sources, uptake, and metabolism

Abstract

ws Declaration of orginality:The work presented in this thesis is, to my best knowledge and beUef, original and my own work. References to others are acknowledged in the text and contributions of others noted in the statement of contributions by others. This material has not been submitted, either in whole or in part, for a degree at the University of Queensland or any other University. Ian Maxwell Biggs Acknowledgments:This project was funded by a PhD research scholarship from the Sugar Research and Development Corporation.I wish to deeply and sincerely thank Professor Christa Critchley for her rescuing this project when it was all but sunk. Her enthusiasm for a project outside her specialist field and when she akeady had a heavy workload has motivated me to completing this thesis.Special thanks to my other supervisors Professor George Stewart, Dr John Wilson, and Dr Hock Ng for their advice, encouragement, and proofreading time and skills.Thank you to Peter Thorbum, Brian Keating and Ian ValUs, CSIRO Tropical Agriculture, for sharing their thoughts on sugarcane agriculture, amino acids in sugarcane and soil nitrogen profiles under cultivated sugarcane. I would like to thank CSIRO in general for the assistance in completing this thesis on a part-time basis while maintaining my fulltime workload.Many thanks to the members of the old 'Club Metab', Susanne Schmidt, Peter Erskine, Vicki Cramer, Geoff Woodall, Scott McNeil, Nicole Robinson, Marcos Adair, Tanuwong Sangtiean, Xinhua He, Gordon Moss, Rosemary Goodall, and Jan Stewart. The many coffees, chats, and beers all helped for a full and enjoyable time as a PhD student.To the staff of the CSIRO Cunningham Library, Patrick, Robyn, Kaye, Kerry, and Nettie, thankyou for your assistance in literature searching and tracking down those elusive references. A thank you to the staff of the University of Queensland Biological Sciences Library for their assistance in the early years of this project. To the general and administrative staff of the Department of Botany, University of Queensland, thankyou for assistance in glasshouse experiments, equipment maintenance, photocopying and the supply of general materials for labs, and general administrative requirements.Warm and special thanks to my family for their support and love throughout this ordeal. Especially Lisha for her unfailing support and love, even when I was firustrated, cranky and generally angry about everything while writing the words in this book. Jeimifer and Colin for reading thesis draft and their comments and advice, and of course thank you Mum. u statement acknowledging the contribution of others:Brian Keating, Vic Catchpoole, and Ian ValUs (CSIRO Tropical Agriculture) established an experimental site at Bundaberg ("Schulte" site, Chapter 2) and allowed me access to the site for sampling as well as providing samples collected at the site from previous years. Graham Kingston (Bureau of Sugar Experiment Stations (BSES), Bundaberg) provided access to the Yandina site and historical samples from that site.Grah...

Simulations of Nitrate Leaching from Sugarcane Farm in Metahara, Ethiopia, Using the LEACHN Model

“…This shows that the rate of N application on the farm is 8.667 kg N t −1 cane for sugarcane plant, 10.83 kg N t −1 cane for the first and second ratoon crops and 13 kg N t −1 canes for the third ratoon crops. However, according to different literatures, the nutrient uptake capacity of sugarcane is very low, 2.8 kg N t −1 cane [28]. Therefore, in this case, the target nitrogen uptake for sugarcane was taken as (12 ton cane ha −1 * 2.8 kg N t −1 cane) 33.6 kg N/ha.…”

A Data-Driven Approach to Sugarcane Breeding Programs with Agronomic Characteristics and Amino Acid Constituent Profiling

“…Most studies targeting sugarcane metabolites have tested various parts of the plant, including the leaves [23][24][25][26], buds [27], roots [23,26], rinds [28], and stalks [23,[25][26][27]29]. Few studies have analyzed sugarcane juice collected from breeding programs at research institutes [30] or from sugar-producing factories [7,16,19].…”

Adubação nitrogenada em soqueiras de cana-de-açúcar: influência do uso em longo prazo de fontes e/ou doses de nitrogênio

“…Algumas espécies de plantas, como beterraba e tabaco apresentam menor área foliar e número de folhas quando supridas somente com amônio, se comparadas com plantas supridas com nitrato como forma única ou dominante de N (RAAB; TERRY, 1994;WALCH-LIU et al, 2000). Confirmando os resultados destes anteriores mostraram que a produção de biomassa da cultura foi similar para o fornecimento de amônio e nitrato (ARMAS et al, 1992;BIGGS, 2003). No presente estudo as plantas nutridas com a fonte amoniacal não desenvolveram sintomas de toxidez ao amônio, contudo, essa forma de N promoveu redução na área foliar e produção de biomassa das plantas, sendo que o melhor desenvolvimento das plantas de cana-de-açúcar deu-se com o uso da fonte nítrica.…”

“…) Biggs (2003). afirmou que o colmo pode ser o melhor indicador do estatus de N na planta que as folhas, uma vez que o aumento no fornecimento de N aumenta o acúmulo de N no colmo, mas nem sempre ocorre o mesmo nas folhas.…”