HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dhugga, K. S. Search for Related Content PubMed Articles by Dhugga, K. S. Agricola Articles by Dhugga, K. S. Related Collections Sustainable Agriculture Carbon Sequestration Biofuels

Maize Biomass Yield and Composition for Biofuels

Genetic Discovery, Crop Genetics Research and Development, Pioneer Hi-Bred International, Inc., A DuPont Company, 7300 NW 62nd Ave., Johnston, IA 50131

View larger version (12K): [in this window] [in a new window]   Figure 1. (A) Agricultural area under different crops and (B) residue produced by each crop or crop group. The "Others" in A refers to area under pastures and ranges from which no biomass is removed. Data from Wright et al. (2006).

View larger version (9K): [in this window] [in a new window]   Figure 2. Structure of maize stover glucuronoarabinoxylan (GAX). Abbreviations: Ace, acetate; Araf, arabinofuranose; Fer, ferulate; GlcA, glucuronate; Xyl, xylose. Arabinose/xylose ratio is 0.1, glucuronate/xylose 0.2, and ferulate ester/arabinose 0.4 in a corn stalk (Jung and Casler, 2006a,b). All of arabinose and most of glucuronate in stover are assumed to occur as GAX, with the remainder of glucuronate present as potentially in other forms, e.g., trace amounts of pectin. Acetate concentration in maize stover has been reported to be 30 to 50 g kg–1 of dry matter (McAloon et al., 2000; Wooley et al., 1999). Assuming that all of it occurs in GAX and adjusting for molarity, approximately one-third to half of the xylosyl residues on GAX are expected to be acetylated.

View larger version (12K): [in this window] [in a new window]   Figure 3. Grain yield of corn over the last century in the United States. Data from USDA (2007).

View larger version (14K): [in this window] [in a new window]   Figure 4. Production of ethanol from corn stover relative to grain at two levels of stover collection. At a production efficiency of 400 L Mg–1 (2.65 gal bu–1), an ethanol yield of 3.7 kL ha–1 (400 gal acre–1) is expected from the grain. The x-axis represents the relative efficiency of conversion of stover into ethanol in comparison to grain. Amounts of ethanol obtained from stover under two collection scenarios are shown on the y-axis.

View larger version (17K): [in this window] [in a new window]   Figure 5. Predicted effects of altering oil or protein (grain) or lignin (stover) on bioproductivity in maize. Starting composition for grain was taken as 90 g kg–1 protein, 40 g kg–1 oil, 20 g kg–1 ash, and by subtraction, 850 g kg–1 carbohydrates (starch and fiber). Initial composition for stover was 730 g kg–1 carbohydrates, 180 g kg–1 lignin, 40 g kg–1 protein, and 50 g kg–1 ash. Replacement of lignin, oil, or protein only by carbohydrates is assumed. Although oil requires most energy for its synthesis, relatively steeper slopes for lignin and protein are a result of their higher initial amounts (180 and 90 g kg–1, respectively, compared with 40 g kg–1 for oil) in the respective tissues.