Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2013 Evaluation and prediction of corn stover biomass and composition from commercially available corn hybrids Ty Jason Barten Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Agricultural Science Commons, Agriculture Commons, and the Agronomy and Crop Sciences Commons Recommended Citation Barten, Ty Jason, "Evaluation and prediction of corn stover biomass and composition from commercially available corn hybrids" (2013). Graduate Theses and Dissertations. 13347. https://lib.dr.iastate.edu/etd/13347 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Evaluation and prediction of corn stover biomass and composition from commercially available corn hybrids by Ty Jason Barten A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Crop Production and Physiology Program of Study Committee: Kenneth Moore, Major Professor Emily Heaton Allen Knapp Kendall Lamkey Fernando Miguez Iowa State University Ames, Iowa 2013 Copyright © Ty Jason Barten, 2013. All rights reserved. ii TABLE OF CONTENTS Page LIST OF FIGURES ........................................................................................................ iv LIST OF TABLES .......................................................................................................... vi NOMENCLATURE ....................................................................................................... vii ACKNOWLEDGEMENTS ............................................................................................. viii ABSTRACT .................................................................................................................. x CHAPTER 1 REVIEW OF LITERATURE ....................................................................... 1 Introduction ........................................................................................................ 1 Composition of Corn Stover ............................................................................... 4 Collection and Fractionation ............................................................................... 8 Sustainable Collection of Corn Stover ................................................................ 9 Allometry ....................................................................................................... 17 Harvest Index ..................................................................................................... 24 References ...................................................................................................... 32 CHAPTER 2 VARIATION IN BIOMASS YIELD AND CHEMICAL COMPOSITION OF CORN STOVER .............................................................................. 37 Abstract ........................................................................................................ 37 Introduction ........................................................................................................ 38 Materials and Methods ....................................................................................... 40 Results ........................................................................................................ 45 Discussion ........................................................................................................ 51 Conclusions ........................................................................................................ 53 References ........................................................................................................ 54 iii Page CHAPTER 3 UTILITY OF HARVEST INDEX TO PREDICT STOVER BIOMASS IN CORN HYBRIDS ............................................................................................. 63 Abstract ........................................................................................................ 63 Introduction ........................................................................................................ 64 Materials and Methods ....................................................................................... 71 Results and Discussion ........................................................................................ 73 Conclusions ........................................................................................................ 77 References ........................................................................................................ 80 CHAPTER 4 DEVELOPMENT OF AN ALLOMETRIC MODEL TO QUANTIFY CORN STOVER BIOMASS ......................................................................... 86 Abstract ........................................................................................................ 86 Introduction ........................................................................................................ 87 Materials and Methods ....................................................................................... 92 Results and Discussion ........................................................................................ 97 Conclusions ........................................................................................................ 103 References ........................................................................................................ 106 CHAPTER 5 SUMMARY AND CONCLUSIONS .................................................... 121 Summary ............................................................................................................ 121 Conclusions ........................................................................................................ 122 References ......................................................................................................... 126 APPENDIX A Chapter II Supporting Data ................................................................ 127 APPENDIX B Chapter IV Supporting Data .............................................................. 142 iv LIST OF FIGURES Page Figure 2-1 Fractional masses of all stover samples collected across all locations just before grain harvest in 2008 and 2009. .................... 59 Figure 2-2 Moisture of plant fractions across all locations and hybrids just before grain harvest. ....................................................................... 60 Figure 2-3 Fiber and ash composition distribution of plant fractions before grain harvest .................................................................................... 61 Figure 2-4 Elemental macro-nutrient concentration of stover fractions on a dry matter basis ............................................................................. 62 Figure 3-1 Harvest Index by plant population density and year ..................... 82 Figure 3-2 Harvest index by yield level attained in each plot by planting density in 2011 ................................................................................ 83 Figure 3-3 Harvest index by yield level attained in each plot by planting density in 2012 ................................................................................ 84 Figure 3-4 Prediction of stover biomass using a static harvest index of 0.52 kg kg-1 and grain mass from plots sampled in 2011 and 2012 ........ 85 Figure 4-1 Fractional stover masses for the 2011 and 2012 allometric model data set ........................................................................................... 109 Figure 4-2 Actual total stover (kg ha-1) DMB vs. predicted (kg ha-1) from the three predictive MLR for each fraction (stalk, cob, husk) evaluated in the model data set. .................................................... 110 Figure 4-3 Actual stalk mass (kg ha-1) vs. predicted for the model data set .... 111 Figure 4-4 Actual vs. predicted cob mass (kg ha-1) from model data set ........ 112 Figure 4-5 Actual vs. predicted husk mass (kg ha-1) from model data set. ...... 113 v Figure 4-6 Actual total stover weight (kg ha-1) vs. predicted for the validation data set ........................................................................................... 114 Figure 4-7 Actual stalk fraction weight (kg ha-1) vs. predicted for the validation data set. .......................................................................... 115 Figure 4-8 Actual cob weight (kg ha-1) vs. predicted for the validation data set. ........................................................................................... 116 Figure 4-9 Actual husk weight (kg ha-1) vs. predicted for the validation data set ............................................................................................ 117 Figure 4-10 Plot of model data set for single plant OD stalk biomass vs. calculated volume .......................................................................... 118 vi LIST OF TABLES Page Table 2-1 Descriptive table of entries sampled by year and the subsequent data analysis .................................................................................. 57 Table 2-2 Summary statistics for dry matter of stover fractions and mean concentration values for moisture,