Genetic Variability of Elemental Concentration in Winter Wheat Straw

Energy Fuels 2010, 24, 2020–2027 Published on Web 02/04/2010

: DOI:10.1021/ef901181h

Genetic Variability of Elemental Concentration in Winter Wheat Straw† H. M. El-Nashaar,‡ G. M. Banowetz,*,‡ C. J. Peterson,§ and S. M. Griffith‡ ‡

United States Department of Agriculture (USDA)/Agricultural Research Service (ARS), 3450 Southwest Campus Way, Corvallis, Oregon 97331, and §Department of Crop and Soil Science, Oregon State University, Corvallis, Oregon 97331 Received October 20, 2009. Revised Manuscript Received January 21, 2010

Winter wheat (Triticum aestivum L.) occupied 79% of the Pacific Northwest (PNW) total acreage devoted to wheat production in 2007 and represented the foundation of many agricultural enterprises in this region. Straw produced as a co-product of the grain crop has potential as a feedstock for bioenergy production, but certain elements, including silicon (Si) and alkalis, that are characteristic of cereal straws restrict their use in thermochemical technologies. Little is known about genotypic differences in the elemental content among PNW winter wheat cultivars or the amount of macro- and micronutrients removed by straw harvest. In this study, the concentrations of Si and 19 other elements in straw harvested from 20 wheat cultivars grown at three locations in Oregon were quantified. There was significant genetic variability in the concentration of certain elements among these cultivars, and location affected the element accumulation. The Si content varied 3-fold, ranging from 10 604 to 30 903 mg kg-1. On average, the harvest of wheat straw removed 6.42 g of nitrogen (N), 0.4 g of phosphorus (P), and 14 g of potassium (K) kg-1. The harvest of wheat tissues below the flag leaves removed an additional 6.43, 0.23, and 17.8 g of N, P, and K kg-1, respectively. While the yield and desirable end-use traits will remain the goal of breeding programs, these results suggest that selections for lower concentrations of undesirable elements, such as Si, K, and chlorine (Cl), could enhance the utility of straw for thermochemical conversion to bioenergy and other co-products.

metal surfaces of boilers and severely affect their performance and operation cost.4-6 One form of thermochemical combustion is gasification, combustion of biomass under limited oxygen conditions to produce synthesis gases (syngas) that can be converted to energy.7 A recent study showed that the quality and yield of syngas produced from switchgrass was temperaturedependent and the greatest carbon (C) conversion occurred at temperatures in excess of 750 °C.8 At operational temperatures, where C conversion efficiency is high, silicon (Si), which is abundant in wheat residues, and sulfur (S) react with potassium (K), chlorine (Cl), and other alkalis to form slag or alkali silicates. Reduced elemental contents of harvested feedstock improved the combustibility of biomass.9 Environmental conditions have a significant influence on wheat grain quality,10 but the relative magnitude of genetic (G), environmental (E), and G E effects on the elemental content of wheat straw has not been demonstrated. It is wellestablished that soil nitrogen (N) availability influences wheat grain protein content, which, in turn, affects baking quality and the quantity of straw produced.11 Genotypes, however, may not all respond similarly to the variation in soil elemental

Introduction Considerable quantities of wheat straw are produced annually as co-products of grain production in the Pacific Northwest.1 When this straw is returned to the field after grain harvest, it serves as a useful forage refuge, provides ecosystem services that benefit water and soil quality, and can impact fertilization requirements for the following crop.2 Quantities of straw that exceed the amount recommended as residue for conservation purposes have potential utility as feedstock for bioenergy production. Successful use of straw for this purpose requires an understanding of genetic and environmental factors that influence the suitability of straw for conversion technologies. Elemental content has a large impact on the utility of cereal straws in thermochemical conversion processes.3 In comparison to coal, biomass generated from agricultural residues, such as straw, has undesirable characteristics that include increased quantities of alkali elements, which contribute to fouling, slagging, which is the formation of deposits on boiler surfaces, fouling, and the formation of deposits on the surfaces of other equipment connected to boilers.3 Both slagging and fouling corrode † Disclaimer: The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the United States Department of Agriculture or the Agricultural Research Service of any product or service to the exclusion of others that may be suitable. *To whom correspondence should be addressed: USDA/ARS, 3450 S.W. Campus Way Corvallis, OR 97331. Telephone: (541) 738-4168. E-mail: [email protected]. (1) Banowetz, G. M.; Boateng, A.; Steiner, J. J.; Griffith, S. M.; Sethi, V.; El-Nashaar, H. M. Biomass Bioenergy 2008, 32, 629–634. (2) Cassman, K. G. Proc. Natl. Acad. Sci. U.S.A. 1999, 96, 5952– 5959. (3) Jenkins, B. M.; Baxter, L. L.; Miles, T. R., Jr.; Miles, T. R. Fuel Process. Technol. 1998, 54, 17–46.

r 2010 American Chemical Society

(4) Olanders, B.; Steenari, B. M. Biomass Bioenergy 1995, 8, 105–115. (5) Tillman, D. A. Biomass Bioenergy 2000, 19, 365–384. (6) Werther, J.; Saenger, M.; Hartge, E. U.; Ogada, T.; Siagi, Z. Prog. Energy Combust. Sci. 2000, 26, 1–27. (7) McKendry, P. Bioresour. Technol. 2002, 83, 47–54. (8) Boateng, A. A.; Hicks, K. B.; Vogel, K. P. J. Anal. Appl. Pyrolysis 2006, 75, 55–64. (9) Nordin, A. Biomass Bioenergy 1994, 6, 339–347. (10) Peterson, C. J.; Graybosch, R. A.; Baenzinger, P. S.; Grombacher, A. W. Crop Sci. 1992, 32, 98–103. (11) Kimball, B. A.; Morris, C. F.; Pinter, P. J., Jr.; Wall, G. W.; Hunsaker, D. J.; Adamsen, F. J.; LaMorte, R. L.; Leavitt, S. W.; Thompson, T. L.; Matthias, A. D.; Brooks, T. J. New Phytol. 2001, 150, 295–303.

2020

pubs.acs.org/EF

Energy Fuels 2010, 24, 2020–2027

: DOI:10.1021/ef901181h

El-Nashaar et al. 12

content and the nutrients available for plant uptake. Soil elemental concentrations alone do not account for variations in elemental contents of straw collected from different genotypes of Miscanthus, a C4 grass.13 Wheat breeders routinely use grain yield and quality as their primary selection criteria, and grain quality will continue to be the primary goal. Nevertheless, selection based partially on straw elemental concentrations may supplement grain quality and add value to the crop if this residue has value as a bioenergy feedstock. Little information about genetic variability of elemental concentrations in wheat straw is available to breeders, and little is known about the effect of the production location or variation in elemental concentrations because of differential responses of genotypes to the environment. In this study, the concentrations of Si and 19 other elements in straw and standing wheat stubble of 20 cultivars of winter wheat grown at three different locations were quantified. The objective of this research was to determine whether straw from contrasting wheat genotypes differed in mineral content and whether the location affected the concentration of elements that influence the suitability of wheat straw for thermochemical conversion and to quantify the amount of mineral loss from the production system by straw removal.

were also collected but only from 8 of the 20 cultivars grown at the Pendleton site. This stubble was collected from three random sites within each plot, pooled, and treated as one replication. The straw and stubble samples were dried at 80 °C for 24 h and ground, using a Cyclotec 1093 sample mill (Tecator, Hoganas, Sweden). Soil mineral analysis was conducted on three 2.54 cm diameter soil cores collected to a depth of 30 cm from each of the four quadrants where plant samples were harvested.18 Plant and soil elemental analysis for Al, As, B, Cu, Ca, Fe, K, Mg, Mn, Mo, Ni, P, Si, and Zn were performed using microwave-assisted acid digestion [Environmental Protection Agency (EPA) method 3052], using an Ethos D microwave station (Milestone, Monroe, CT), and subsequent analysis on an inductively coupled plasma-optical emission spectrometer (ICP-OES) (PerkinElmer Life and Analytical Sciences, Shelton, CT). Soil analyses were conducted on dried soil using the same digestion and ICP protocols. For Cl analysis, plant and soil samples (25 g) were extracted with 100 mL of deionized water and shaken on a New Brunswick Scientific shaker (NBS Co., Inc., Edison, NJ) for 30 min at 350 rpm. After shaking, samples were filtered through Whatman Qualitative No. 42 filters (Florham Park, NJ) that had been washed 3 times with 1% H2SO4 (v/v) and deionized water. The filtrate was analyzed colorimetrically for Cl (QuickChem method 10-117-07-1-C) on a Lachat flow injection autoanalyzer (Hach Co., Loveland, CO). Soil organic matter was determined by the loss on ignition at 500 °C for 4 h, and soil pH was determined on a slurry consisting of 1:2 double-distilled water (ddH2O)/soil. Total C and N were determined using a PerkinElmer 2400 series II CHNS/O combustion analyzer (Shelton, CT). Four replicate 2.5 cm cores of soil samples were randomly collected at each field site, dried, and analyzed. Plant available soil phosphorus (P), N, K, and S were determined by the OSU Soil Testing Laboratory, as described.14 Statistical analyses of mean differences among wheat populations and locations and mean comparisons between the two sources of wheat residues collected were calculated by applying PROC MIXED and PROC CORR analysis procedures of SAS (SAS Institute, Inc., Cary, NC) in a randomized complete block design (RCBD). In the analysis of variance models, the location was considered random and cultivars and wheat residue sources were considered fixed. Means of all elements evaluated for main effects and the interaction of the locations, cultivars, and sources of wheat residues were compared by applying Fisher’s least significant difference (LSD) mean comparison test in SAS.

Materials and Methods A total of 20 cultivars or breeding lines of soft white wheat were selected to represent the most widely grown winter wheat varieties in the Pacific Northwest. Winter wheat genotypes were planted in 6-row plots of 1.52 4.57 m, where cultivars were arranged in a randomized complete block design (RCBD). Blocks represented the replications, and plots represented the cultivars. Four blocks represented four replications, but only three of the four replications were sampled and analyzed for mineral concentration. The plots were established in October 2006 at three Pacific Northwest sites, including Corvallis, OR [Oregon State University (OSU) Hyslop Research Farm] (Woodburn silt loam), and at OSU experimental stations in Moro, OR (Walla Walla silt loam), and Pendleton, OR (Walla Walla silt loam). The three experimental stations include a range of environmental conditions and vary in elevation, rainfall, and temperature. The Hyslop experimental station (44°380 0300 N/123°110 2400 W) is located at a an elevation of 70.10 m, with temperature averages of 4.05-19 °C and an annual precipitation of 108.46 cm. The Moro experimental station (45.49°N/120.74°W) is located in Moro County, OR, at an elevation of 609.90 m, where temperatures range from 3.11 to 28.44 °C and the annual precipitation is 29.72 m. The Pendleton experimental station (45.68°N/118.78°W) is located in Umatilla County, OR, at an elevation of 367.89 m, where temperatures range from 0.83 to 22.72 °C and the annual precipitation is 30.48 cm. A pre-planting application of nitrogen (46-0-0) at a rate of 332 kg ha-1 was supplied to the Corvallis plots. Plots in Moro received applications of N in August (106 kg ha-1) and September (73 kg ha-1). Plots at Pendleton were fertilized using 90 kg ha-1 of N from dry ammonium sulfate, applied in August. Grain was harvested from the plots in July, 2007. Grab samples of wheat straws were collected at all three locations from each of the 20 cultivars as the residues exited the combine harvester. The harvestor was adjusted to a cutting height of approximately 11 cm below the flag leaf, the most common cutting height used for grain harvest in the region. Three replicates of 20 cultivars provided 60 samples per location. Additional wheat straw samples that represented stubble cut at 11 cm above the soil surface

Results Soil collected from the Corvallis field site had a pH of 6.7, which differed significantly ( p = 0.05) from the pH of soils collected from Moro (pH 5.9) and Pendleton (pH 6.1). Soils collected from the three locations also contained different concentrations of B, Ca, Cd, Fe, and Zn, but there were no significant differences in As or Cu concentrations (Table 1). Soil from the Corvallis site contained the greatest concentrations of Al, B, Cd, Cr, Fe, K, Mn, Ni, P, Si, Zn, H, and N, while soil at the Moro site contained the greatest concentrations of Ca, Mg, and Mo. Soil from Pendleton had the highest concentrations of S and C (Table 1). Quantities of N, P, and K available for plant uptake at Corvallis were 1.15, 0.056, and 0.21 g kg-1 of soil. Similarly, the quantities of available N, P, and K in soil at the Moro site were 0.13, 0.062, and 0.25 g kg-1, while those from soil at Pendleton were 0.10, 0.059, and 0.24 g kg-1.

(12) Feng, J. Crit. Rev. Plant Sci. 2005, 24, 267–281. (13) Lewandowski, I.; Clifton-Brown, J. C.; Andersson, B.; Basch, G.; Christian, D. G.; Jorgensen, U.; Jones, M. B.; Riche, A. B.; Schwarz, K. U.; Tayebi, K.; Teixeira, F. Agron. J. 2003, 95, 1274–1280.

(14) Gavlak, R.; Horneck, D.; Miller, R.; Kotuby-Amacher, J. Soil, plant and water reference methods for the western region. Utah State University, Logan, UT, 2003.

2021

Energy Fuels 2010, 24, 2020–2027

: DOI:10.1021/ef901181h

El-Nashaar et al.

Tables 2-5 represent the mean elemental concentrations in combine-harvested wheat residues, as well as wheat stubble of 20 released and experimental cultivars averaged over the three Pacific Northwest sites. While significant differences in concentrations among cultivars occurred for most minerals, in many cases, the range of concentrations for a given mineral was relatively small. In contrast, certain minerals that impact the suitability of straw for thermochemical conversion showed considerable variation among cultivars. The concentration of Cl varied over 2-fold between Goetze (least Cl) and Masami (the greatest amount). Similarly, the range of concentration of Si, one of the most abundant minerals and a critical component of slag production in thermochemical processes, was notable.

ORSS-1757 contained the least Si over the three locations, while Goetze accumulated the greatest concentration of this mineral. Stephens and Gene, two widely used cultivars in the region, contained the greatest quantities of Ca. The concentrations of K, an important nutrient and an alkali component that contributes to slag formation, ranged from 11 530 mg kg-1 in UICF-Lambert to 15 943 mg kg-1 in Gene. There were also significant differences in the concentrations of the other nutrients, including N, P, and S, among these genotypes. Averaged over the three locations, N, P, and K concentrations in these 20 cultivars were 6.42, 0.4, and 14 g kg-1 of field combine residues, respectively. Elemental concentrations of straw exiting the combine were compared to those in standing straw stubble consisting of the portion of the wheat plant remaining in the ground after grain harvest (Tables 4 and 5). Stubble from the Pendleton site that included eight of the most widely grown wheat cultivars contained similar or lower concentrations of most elements relative to those measured in the combine residues. Concentrations of Si, an element that impacts thermochemical processes, and the plant nutrient P were generally lower in the standing stubble. There were apparent location-associated differences in the concentrations of certain elements, including those that impact thermochemical conversion processes, with wheat cultivars among these (Tables 6-11). Despite the fact that soil K concentrations were greatest at Corvallis (Table 1), the concentrations of this element in straw produced at this site were generally lower than those measured in straw from the Pendleton site, where average soil K concentrations were lower (Tables 6, 8, and 10). The concentration of K in ORCF-102 was among the greatest of the wheat cultivars produced at Corvallis and Pendleton, while Xerpha and UICF-Lambert contained some of the lowest K concentrations at two of the sites (Tables 6 and 10). Stephens and Gene contained some of the greatest Ca concentrations at each site, while Weatherford and ORCF-101 straws had some of the lowest concentrations of this element. Masami and ORCF102 contained greater concentrations of Cl, while Madsen and

Table 1. Elemental Analysis of Soils Collected from Corvallis, Moro, and Pendleton, OR, Locationsa element

Corvallis

Moro

Pendleton

Al As B Ca Cd Cr Cu Fe K Mg Mn Mo Ni P S Si Zn

67973 a 15.7 a 840.75 a 6860 c 3.55 a 48.77 a 22.81 a 38668 a 20088 a 8599 b 1722 a 0.206 b 461 a 1550 a 0.725 a 104120 a 148 a

(mg kg-1) 65988 ab 15.0 a 611.55 c 17073 a 2.68 c 39.27 b 23.25 a 29735 c 14500 b 9020 a 758 b 0.586 a 249 b 643 b 0.530 b 50343 b 101 c

63713 b 16.4 a 663.33 b 14565 b 3.04 b 36.50 b 23.11 a 31320 b 14148 b 8548 b 836 b 0.405 ab 223 b 602 b 0.760 a 44440 b 122 b

C H N

45.95 b 16.58 a 0.235 a

(%) 46.20 b 11.40 b 0.185 b

44.18 a 13.25 a 0.235 a

a Values across rows followed by the same letter are not significantly different ( p = 0.05) using Fisher’s LSD mean comparison test.

Table 2. Mean (n = 3) Concentration of Selected Elements in Combine-Harvested Residues of 20 Winter Wheat Cultivars Averaged across Corvallis, Moro, and Pendleton, OR, Locationsa element wheat cultivar

Al (mg kg-1)

Ca (mg kg-1)

Mg (mg kg-1)

K (mg kg-1)

P (mg kg-1)

H (g kg-1)

C (g kg-1)

N (g kg-1)

S (g kg-1)

Brundage 96 Cara Xerpha ORCF-103 Gene Skiles UICF-Lambert Madsen Masami Goetze ORCF-101 ORCF-102 ORSS-1757 Rod/Tubbs06 Simon Stephens Tubbs Tubbs06 Weatherford Westbred 528

439 bcde 504 abcd 454 abcde 454 abcde 537 ab 514 abc 567 a 398 cde 446 abcde 454 abcde 380 e 448 abcde 454 abcde 426 bcde 452 abcde 376 e 462 abcde 387 de 377 e 439 bcde

2360 abc 2359 abcd 2175 abcde 2417 ab 2478 a 2120 abcde 1992 cde 1892 e 2046 bcde 2172 abcde 1772 e 1929 e 1966 cde 1981 cde 2009 cde 2487 a 2063 bcde 2104 abcde 1876 e 1953 de

1581 a 1152 efgh 1186 defgh 1505 abc 1296 cdef 1222 defgh 1260 defg 1313 cdef 1568 ab 1066 gh 999 h 1392 abcd 1131 fgh 1283 cdefg 1228 defg 1224 defgh 1236 defg 1365 abcde 1306 cdef 1345 bcdef

14574 ab 12920 ab 11815 b 14145 ab 15943 a 13873 ab 11530 b 13438 ab 14647 ab 13942 ab 14260 ab 15650 a 15688 a 12707 ab 13521 ab 13803 ab 14001 ab 14594 ab 14606 ab 15450 a

518 a 334 e 400 bcde 477 ab 399 bcde 460 abc 364 cde 360 de 428 bcde 446 abcd 360 de 432 abcd 356 de 348 de 433 abcd 382 bcde 349 de 388 bcde 394 bcde 373 cde

16.9 f 18.3 bcd 18.1 bcde 18.1 bcde 17.2 ef 17.7 bcdef 18.2 bcde 31.0 a 18.0 bcde 17.1 ef 18.4 b 18.6 b 17.2 ef 18.2 bcde 18.5 b 31.5 a 16.7 f 17.2 cdef 17.2 def 18.3 bc

402 abcde 404 abcd 404 abcd 394 abcdef 389 cdef 392 bcdef 380 f 407 abc 395 abcdef 398 abcdef 396 abcdef 399 abcdef 399 abcdef 412 a 406 abc 385 ef 408 ab 387 def 403 abcde 401 abcde

6.36 ab 6.37 ab 6.40 ab 6.49 ab 6.56 ab 6.43 ab 6.65 a 6.30 ab 6.53 ab 6.33 ab 6.43 ab 6.41 ab 6.45 ab 6.16 b 6.29 ab 6.70 a 6.16 b 6.60 a 6.44 ab 6.36 ab

0.950 ab 0.940 ab 0.944 ab 0.989 ab 0.889 ab 0.928 ab 0.961 ab 0.938 ab 0.923 ab 0.970 ab 0.979 ab 1.006 ab 0.960 ab 1.013 a 1.013 a 1.014 a 0.931 ab 0.942 ab 0.941 ab 0.872 b

a

Values within columns followed by the same letter are not significantly different ( p = 0.05) using Fisher’s LSD mean comparison test.

2022

Energy Fuels 2010, 24, 2020–2027

: DOI:10.1021/ef901181h

El-Nashaar et al.

Table 3. Mean (n = 3) Concentration of Elements in Combine-Harvested Residues of 20 Winter Wheat Cultivars Averaged across Corvallis, Moro, and Pendleton, OR, Locationsa element B As wheat cultivar (mg kg-1) (mg kg-1) Brundage 96 Cara Xerpha ORCF-103 Gene Skiles UICFLambert Madsen Masami Goetze ORCF-101 ORCF-102 ORSS-1757 Rod/Tubbs06 Simon Stephens Tubbs Tubbs06 Weatherford Westbred 528 a

Cl (mg kg-1)

Co Cu Fe Mn Mo Ni (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1)

Si (mg kg-1)

Zn (mg kg-1)

12.7 ab 13.1 ab 12.6 ab 12.8 ab 13.7 a 12.3 ab 12.8 ab

65.4 abcd 73.5 a 61.3 bcde 59.7 cde 52.9 e 71.0 ab 53.7 e

1644 bc 1292 efghi 1505 bcdefg 1486 cdefgh 1495 bcdefg 1292 efghi 1613 bcd

1.32 a 1.09 ab 1.03 ab 1.03 ab 0.99 ab 0.99 ab 1.07 ab

11.2 cde 12.1 cde 11.4 cde 12.6 bcde 14.8 abc 12.6 bcde 17.2 a

205 ab 211 ab 173 abcd 184 abc 193 abc 215 a 190 abc

92.3 a 86.1 ab 78.7 bc 72.2 cde 45.2 g 67.8 cdef 67.0 cdef

1.76 ab 1.70 ab 1.72 ab 1.75 ab 1.85 a 1.93 a 1.64 ab

82.9 bcd 84.3 bc 77.1 bcd 82.9 bcd 89.0 ab 85.1 bc 89.6 ab

18125 bcde 18972 bcd 16709 bcdef 18619 bcde 19232 abc 18564 bcde 20041 ab

6.18 abcd 7.69 ab 6.26 abcd 6.69 abc 6.65 abc 6.20 abcd 7.71 a

12.0 b 12.2 ab 12.2 ab 12.4 ab 13.0 ab 12.9 ab 13.2 ab 11.9 b 12.6 ab 11.6 b 13.2 ab 12.5 ab 12.8 ab

52.6 e 67.7 abc 65.5 abcd 59.5 cde 55.1 de 68.2 abc 56.8 de 59.8 cde 60.1 cde 55.8 de 54.6 e 53.1 e 58.2 cde

1554 bcde 2168 a 1034 i 1769 b 2156 a 1345 defgh 1431 cdefgh 1432 cdefgh 1349 defgh 1208 hi 1234 ghi 1263 fghi 1544 bcdef

1.06 ab 1.17 ab 1.07 ab 0.93 b 1.06 ab 1.05 ab 0.95 b 1.09 ab 0.95 b 1.01 ab 1.06 ab 0.99 ab 0.95 b

10.4 de 11.7 cde 12.8 bcd 9.6 de 11.6 cde 15.9 ab 11.0 de 10.4 de 11.6 cde 9.7 de 10.4 de 10.1 de 9.0 e

185 abc 163 bcd 189 abc 151 cd 132 d 161 bcd 174 abcd 192 abc 183 abc 175 abcd 197 abc 163 bcd 174 abcd

67.5 cdef 76.3 bcd 77.8 bcd 62.4 ef 78.4 bcd 58.4 fg 65.0 def 70.5 cdef 68.5 cdef 58.2 fg 70.0 cdef 64.9 def 71.2 cdef

1.63 ab 1.84 a 1.74 ab 1.67 ab 1.72 ab 1.71 ab 1.72 ab 1.70 ab 1.65 ab 1.84 a 1.61 ab 1.75 ab 1.49 b

75.0 cd 73.7 cd 101.0 a 73.5 cd 72.9 cd 69.2 d 85.1 bc 83.5 bc 85.5 bc 72.2 cd 77.0 bcd 72.6 cd 81.6 bcd

15806 def 15884 def 22533 a 15897 def 16229 cdef 14776 f 18705 bcde 18172 bcde 18426 bcde 15466 ef 16611 cdef 15642 def 17792 bcdef

5.07 cd 6.13 abcd 5.80 bcd 4.61 d 6.80 abc 6.39 abcd 5.56 cd 5.60 cd 6.02 abcd 4.64 d 5.69 cd 5.19 cd 4.70 d


Table 4. Mean (n = 3) Concentration of Selected Mineral in Combine-Harvested Residues ( CR) and Stubble (ST) of Eight Winter Wheat Cultivars Collected from Pendleton, ORa element wheat cultivar ORCF-103 Madsen Masami ORCF-101 ORCF-102 Stephens Tubbs Tubbs06

residue CR ST CR ST CR ST CR ST CR ST CR ST CR ST CR ST

Al (mg kg-1)

Ca (mg kg-1)

Mg (mg kg-1)

P (mg kg-1)

H (g kg-1)

C (g kg-1)

N (g kg-1)

S (g kg-1)

474 a 241 b 439 a 225 b 482 a 232 b 456 a 228 b 501 a 277 b 474 a 219 b 335 a 178 b 502 a 204 b

2404 a 2143 a 2172 a 1937 a 2187 a 1878 a 1996 a 1699 a 2008 a 1861 a 2653 a 2103 b 1995 a 1468 b 2325 a 1817 b

1679* 1282* 1375 a 1107 a 1667 a 1231 b 1137* 778* 1583 a 1147 b 1001 a 1077 a 1264* 868* 1529 a 1031 b

339 a 261 a 305* 184* 405* 289* 283 a 270 a 331* 228* 287 a 219 a 248 a 165 a 309* 200*

42.6* 45.6* 46.1 a 44.7 a 42.9 b 47.2 a 42.9 b 46.1 a 45.6 a 44.8 a 47.0 a 45.6 a 44.1 a 44.3 a 41.4 b 45.6 a

394 a 398 a 391 a 407 a 391 a 400 a 383 a 398 a 395 a 399 a 358 b 421 a 419 a 401 a 372* 400*

6.69 a 6.43 a 6.65 a 6.23 a 6.95 a 6.56 a 6.37 a 6.64 a 6.41 a 6.45 a 7.28 a 6.06 b 5.59 a 6.45 a 7.17 a 6.63 a

0.990 a 1.013 a 0.920* 1.147* 0.857 a 0.837 a 1.023 a 0.913 a 1.023* 1.110* 0.930 a 0.927 a 1.013 a 0.973 a 0.803 a 0.960 a

a Values within a column for specific residues (CR or ST) followed by the same letter are not significantly different ( p = 0.05). An asterisk represents significant differences of p = 0.10 using least square means and PROC MIXED analysis comparison of SAS.

Tubbs had some of the lowest Cl concentrations. OR8303765 contained relatively high concentrations of Si at each site, whereas Madsen and ORCF-1757 contained the least (Tables 7, 9, and 11). The similar rankings of cultivars in Si and Ni concentrations suggest that factors that regulate the uptake of these two elements are related. Concentrations of C removed with straw harvest serve as one indicator of the impact of straw removal from the cropping system on general soil fertility. The amount of C in these straws was relatively similar, ranging from 358 to 419 g kg-1 (Tables 6, 8, and 10). The elements N, P, K, and S represent elemental nutrients that, with sufficient removal from the cropping system, must be replaced to support future crop growth. Average straw N concentrations ranged from 5.94 to 7.28 g kg-1, similar at the three locations. The range of P and S concentrations was greater, ranging from 0.0213 to 0.757 mg kg-1 and from 0.80 to 1.15 g kg-1, respectively.

Discussion There were apparent genotypic differences in elemental concentrations among the wheat cultivars analyzed in this study, and some of those differences were consistent between the three locations where the wheat was grown. These differences can impact both issues addressed in this study: (1) the quantity of nutrients removed from the production system by straw removal and (2) the suitability of these straws for thermochemical conversion approaches. The greatest variability occurred among cultivars grown in the Moro environment, where ranges of Al, P, Cl, Cd, Cu, Fe, and Si concentrations frequently exceeded 2-fold. Ranges of this magnitude could conceivably impact the utility of contrasting straws as thermochemical feedstock because elements, such as Si, K, S, Cl, P, Ca, and Mg, released during biomass combustion react to form alkali silicates, sulfates, and other compounds associated with 2023

Energy Fuels 2010, 24, 2020–2027

: DOI:10.1021/ef901181h

El-Nashaar et al.

Table 5. Mean (n = 3) Concentration of Selected Minerals in Combine-Harvested Residues (CR) and Stubble (ST) of Eight Winter Wheat Cultivars Collected from Pendleton, ORa element wheat cultivar ORCF-103 Madsen Masami ORCF-101 ORCF-102 Stephens Tubbs Tubbs06

residue

As (mg kg-1)

B (mg kg-1)

Cu (mg kg-1)

Fe (mg kg-1)

Mn (mg kg-1)

Mo (mg kg-1)

Ni (mg kg-1)

Si (mg kg-1)

Zn (mg kg-1)

CR ST CR ST CR ST CR ST CR ST CR ST CR ST CR ST

13.5 a 13.1 a 12.4 a 12.2 a 11.5 a 12.8 a 11.4 a 12.2 a 14.3 a 13.9 a 12.3 a 11.2 a 9.2 b 14.3 a 13.7 a 13.3 a

48.47 a 45.2 a 48.5 a 44.2 a 55.6 a 51.4 a 57.0* 46.1* 46.9 a 45.7 a 48.2 a 45.3 a 49.5 a 35.4 b 47.2* 36.6*

16.53 a 8.65 b 11.44 a 4.83 b 11.94 a 5.14 b 11.62 a 5.13 b 15.93 a 10.14 b 14.72 a 5.05 b 10.27 a 5.03 b 12.83 a 5.50 b

135 a 151 a 195 a 117 b 155 a 102 b 146 a 102 b 142 a 127 a 154* 114* 160 a 82 b 151* 114*

90.5 a 65.6 b 76.6 a 65.0 a 98.4 a 78.3 b 63.9 a 55.1 a 97.2* 78.8* 70.2* 51.7* 65.2* 49.4* 84.8* 66.3*

1.38 a 1.38 a 1.35 a 1.45 a 1.26 a 1.39 a 1.31 a 1.27 a 1.72 a 1.46 b 1.54 a 1.24 b 1.29* 1.50* 1.40 a 1.46 a

102.1 a 87.0 a 114.9 a 85.0 b 101.4 a 79.3 b 96.3 a 92.8 a 97.0 a 89.5 a 131.9 a 83.0 b 97.9 a 66.6 b 109.6 a 75.9 b

23150* 19687* 24210 a 17670 b 22303 a 16743 b 21070 a 19490 a 22563 a 20120 a 28083 a 17670 b 21270 a 13647 b 24087 a 15850 b

7.10 a 2.68 b 4.90 a 1.69 b 6.21 a 1.93 b 5.13 a 1.70 b 8.00 a 3.12 b 6.20 a 1.67 b 3.36* 1.55* 6.24 a 1.81 b

a Values within columns for specific residues (CR or ST) followed by the same letter are not significantly different ( p = 0.05). An asterisk represents significant differences of p = 0.10 using least square means and PROC MIXED analysis comparison of SAS.

Table 6. Mean (n = 3) Concentration of Selected Minerals in Combine-Harvested Residues of 20 Winter Wheat Cultivars Collected from Hyslop Farm, Benton County, ORa element wheat cultivars

Al (mg kg )

Ca (mg kg )

Mg (mg kg )

K (mg kg )

P (mg kg-1)

H (g kg-1)

C (g kg-1)

N (g kg-1)

S (g kg-1)

Brundage 96 Cara Xerpta ORCF-103 Gene Skiles UICF-Lambert Madsen Masami Goetze ORCF-101 ORCF-102 ORSS-1757 Rod/Tubbs06 Simon Stephens Tubbs Tubbs06 Weatherford Westbred 528

496 abc 410 bc 391 bc 465 abc 560 ab 525 abc 658 a 422 bc 450 bc 527 abc 344 c 573 ab 492 abc 414 bc 446 bc 470 abc 443 bc 530 abc 396 bc 386 bc

3213 abc 3106 abcde 2593 bcde 3467 ab 3713 a 2913 abcde 2078 e 2321 cde 2632 bcde 3120 abcd 2178 de 2728 abcde 2620 bcde 2506 bcde 2641 bcde 3120 abcd 2898 abcde 2562 bcde 2670 bcde 2317 cde

1130 a 804 bcde 729 cde 1128 a 887 abcde 911 abcd 703 de 801 bcde 1000 ab 880 abcde 622 e 989 abc 726 cde 837 bcde 808 bcde 897 abcd 920 abcd 893 abcd 908 abcd 826 bcde

11067 abcd 9284 d 9478 cd 12693 abc 12270 abcd 12297 abcd 10996 abcd 10427 bcd 11783 abcd 12777 ab 12913 ab 13917 a 13443 ab 10954 abcd 10390 bcd 12507 abcd 11547 abcd 11685 abcd 10556 bcd 11833 abcd

704 ab 413 e 437 e 597 abcde 757 a 705 ab 450 e 483 cde 596 abcde 667 abc 495 cde 557 bcde 464 e 418 e 651 abcd 550 bcde 505 cde 556 bcde 470 de 467 de

41.6 ef 46.2 ab 45.4 abcd 45.6 abc 42.9 bcdef 44.5 abcde 45.3 abcd 42.3 def 45.3 abcd 42.6 cdef 46.4 a 47.2 a 42.6 cdef 45.8 abc 46.7 a 42.9 bcdef 41.1 f 42.9 bcdef 42.9 bcdef 46.2 ab

405 abc 416 ab 399 abc 390 bc 391 abc 394 abc 389 bc 419 a 394 abc 394 abc 406 abc 403 abc 395 abc 410 abc 399 abc 397 abc 412 abc 383 c 412 abc 392 abc

6.28 bc 6.18 bc 6.24 bc 6.35 abc 6.95 a 6.35 abc 6.32 abc 5.96 c 6.19 bc 6.69 ab 6.27 bc 6.37 abc 6.41 abc 6.29 abc 6.33 abc 6.48 abc 6.10 bc 6.37 abc 6.34 abc 6.42 abc

0.97 a 0.93 a 0.99 a 0.96 a 0.86 a 1.06 a 0.90 a 0.95 a 0.94 a 0.99 a 1.00 a 0.98 a 0.93 a 0.94 a 1.07a 1.04 a 0.88 a 1.02 a 0.88 a 0.90 a

a

-1

-1

-1

-1

Values within columns followed by the same letter are not significantly different ( p = 0.05) using Fisher’s LSD mean comparison.

ash fouling and slag formation.3,15,16 The concentrations of these elements measured in this selection of wheat genotypes were similar to those found by others,3 and considerably greater than those of woody fuels.17 The primary components of straw ash are Si and K along with relatively high levels of Cl.3,18 The K and Cl released from the straw during heating can form low melting point eutectics that become entrained as aerosols within the reactor. Condensation of alkali chlorides in cooler portions of the reactor cause corrosion, and a reaction of these sticky components with ash can cause the formation of a glasslike slag. This is significant because temperature ranges within gasification reactors typically from 650 to 800 °C. As a

consequence, a 2-fold difference in the Si or K concentration could have a significant impact on the suitability of straw for gasification. Xerpha consistently accumulated lower concentrations of K and Si than many of the other wheat cultivars at each location. UICF-Lambert had relatively low concentrations of K and Si when produced at Moro, but it accumulated relatively high levels of Si at Corvallis and Pendleton. Tubbs06 grown at Moro accumulated the least Si in this study. The range of allowable elemental concentrations remains to be determined and will be dependent upon specific conversion technologies. Nevertheless, the relative concentrations documented in this research provide guidelines on relative genotypic performances that might be anticipated. Concentrations of N, P, K, and C provide indicators of macronutrients removed from the production system when the residue is removed.19 The concentrations of these four

(15) Baxter, L. L. Biomass Bioenergy 1993, 4, 85–102. (16) Brown, D.; Gassner, M.; Fuchino, T.; Marechal, F. Appl. Therm. Eng. 2009, 29, 2137–2152. (17) Miles, T. R.; Miles, T. R., Jr.; Baxter, L. L.; Bryers, R. W.; Jenkins, B. M.; Oden, L. L. Biomass Bioenergy 1996, 10, 125–138. (18) Banowetz, G. M.; Griffith, S. M.; El-Nashaar, H. M. Energy Fuels 2009, 23, 502–506.

(19) Hoskinson, R. L.; Karlen, D. L.; Birrell, S. J.; Radtke, C. W.; Wilhelm, W. W. Biomass Bioenergy 2007, 31, 126–136.

2024

Energy Fuels 2010, 24, 2020–2027

: DOI:10.1021/ef901181h

El-Nashaar et al.

Table 7. Mean (n = 3) Concentration of Selected Minerals in Combine-Harvested Residues of 20 Winter Wheat Cultivars Collected from Hyslop Farm, Benton County, ORa element wheat cultivar

B Cl Cd Cu Fe Mn Mo Ni As (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1)

Si (mg kg-1)

Zn (mg kg-1)

Brundage 96 Cara Xerptza ORCF-103 Gene Skiles UICF-Lambert Madsen Masami Goetze ORCF-101 ORCF-102 ORSS-1757 Rod/Tubbs06 Simon Stephens Tubbs Tubbs06 Weatherford Westbred 528

12.5 abc 12.8 abc 12.6 abc 13.1 abc 14.2 a 12.0 bc 12.8 abc 11.9 bc 11.7 bc 12.9 abc 13.5 ab 11.3 c 13.3 abc 12.4 abc 12.5 abc 12.9 abc 12.59 abc 12.8 abc 12.0 bc 12.99abc

17557 ab 14437 bcd 13540 bcd 14053 bcd 14570 bcd 16170 abc 16373 abc 12429 cd 12667 cd 19487 a 13140 bcd 13113 bcd 11153 d 12595 cd 15270 abcd 11803 cd 13273 bcd 15143 abcd 14223 bcd 16093 abc

8.22 abc 9.46 a 6.62 abc 8.03 abc 8.92 ab 8.27 abc 9.12 ab 7.14 abc 7.67 abc 8.09 abc 5.64 c 9.32 ab 7.50 abc 6.25 bc 7.15 abc 8.19 abc 7.03 abc 6.91 abc 6.25 bc 6.82 abc

a

84.4 abc 90.0 ab 74.1 abcd 79.8 abcd 62.6 cd 80.8 abc 54.6 d 67.6 bcd 93.4 a 81.8 abc 67.9 abcd 67.6 bcd 78.7 abcd 70.8 abcd 76.6 abcd 69.7 abcd 71.1 abcd 66.4 bcd 67.5 bcd 70.03abcd

1130 abc 1232 abc 1383 abc 1462 ab 949 c 1119 abc 1441 ab 1020 bc 1298 abc 1515 a 1391 abc 1132 abc 1060 abc 1115 abc 1185 abc 1061 abc 925 c 1222 abc 1209 abc 1155abc

1.10 abcd 1.17 abcd 1.09 abcd 1.09 abcd 1.16 abcd 1.07 bcd 0.98 d 1.23 abc 1.22 abcd 1.24 ab 1.12 abcd 1.15 abcd 0.99 cd 1.08 abcd 1.32 a 1.02 bcd 1.143 abcd 1.13 abcd 1.12 abcd 1.165abcd

12.0 bc 11.4 c 9.8 c 11.3 c 15.4 ab 11.8 bc 18.3 a 11.3 c 12.7 bc 13.0 bc 9.7 c 11.2 c 12.3 bc 11.2 c 10.5 c 11.7 c 11.6 c 9.7 c 10.1 c 9.9c

216 ab 147 b 172 b 175 b 214 ab 208 ab 156 b 201 ab 153 b 221 ab 140 b 156 b 192 ab 160 b 219 ab 206 ab 192 ab 285.3 a 186.3 b 169.0 b

73.9 a 70.8 abc 54.8 abc 43.1 abc 48.9 abc 48.4 abc 44.3 abc 50.9 abc 47.3 abc 73.3 ab 48.4 abc 52.7 abc 41.9 bc 44.6 abc 49.0 abc 64.1 abc 41.5 c 54.0 abc 52.6 abc 56.0 abc

2.35 ab 2.22 ab 2.25 ab 2.42 ab 2.72 a 2.56 ab 2.21 ab 2.20 ab 2.58 ab 2.43 ab 2.39 ab 2.03 ab 2.19 ab 2.30 ab 2.33 ab 2.07 ab 2.78 a 2.09 ab 2.50 ab 1.80 b

79.3 ab 65.7 bcd 63.0 bcd 63.4 bcd 66.7 bcd 73.2 bcd 73.6 abc 58.2 cd 59.8 bcd 87.7a 61.6 bcd 60.6 bcd 53.8 d 57.6 cd 70.2 abcd 55.6 cd 62.3 bcd 69.8 abcd 65.2 bcd 73.0 abcd


Table 8. Mean (n = 3) Concentration of Selected Minerals in Combine-Harvested Residues of 20 Winter Wheat Cultivars Collected from Moro, OR (Sherman County)a element wheat cultivars

Al (mg kg )

Ca (mg kg )

Mg (mg kg )

K (mg kg )

P (mg kg-1)

H (g kg-1)

C (g kg-1)

N (g kg-1)

S (g kg-1)


503 abc 396 bcd 367 bcd 482 abc 541 ab 611 a 373 bcd 332 cd 405 abcd 392 bcd 339 bcd 271 d 397 bcd 487 abc 425 abcd 411 abcd 353 bcd 350 bcd 336 bcd 442 abcd

1529 abcd 1481 abcde 1626 abc 1378 abcdef 1676 ab 1341 abcdef 1310 cdef 1182 def 1319 bcdef 1332 abcdef 1143 ef 1049 f 1289 cdef 1287 cdef 1349 abcdef 1689 a 1295 cdef 1425 abce 1134 ef 1543 abc

1932 ab 1267 def 1493 bcdef 1707 abcd 1842 abc 1486 cdef 1460 cdef 1762 abc 2037 a 1142 f 1236 ef 1603 abcde 1441 cdef 1561 bcdef 1506 bcdef 1776 abc 1523 bcdef 1673 abcde 1558 bcdef 1766 abc

13067 ab 10840 ab 10635 b 9761 b 16073 a 11087 ab 10538 b 12747 ab 14093 ab 11348 ab 12147 ab 12143 ab 13983 ab 10797 ab 12526 ab 10437 b 14227 ab 13600 ab 13002 ab 12473 ab

426 ab 290 bcd 363 abc 494 a 213 d 347 bcd 376 abc 291 bcd 283 cd 363 abc 303 bcd 409 abc 355 abcd 336 bcd 331 bcd 309 bcd 295 bcd 300 bcd 347 bcd 320 bcd

46.2 ab 46.1 ab 45.6 ab 45.6 ab 45.3 ab 45.3 ab 47.0 a 45.8 ab 44.3 b 45.6 ab 46.1 ab 44.8 ab 47.2 a 44.7 ab 45.6 ab 46.7 ab 46.2 ab 46.4 ab 45.4 ab 47.2 a

416 a 391 a 400 a 398 a 394 a 389 ab 358 ab 410 a 401 a 390 ab 398 a 399 a 403 a 407 a 421 a 399 a 392 a 406 a 399 a 400 a

6.18 b 6.65 ab 6.63 ab 6.43 b 6.19 b 6.32 b 7.28 a 6.29 b 6.45 b 6.35 b 6.64 ab 6.45 b 6.37 b 6.23 b 6.06 b 6.33 b 6.42 b 6.27 b 6.24 b 6.56 b

0.93 bcd 0.92 cd 0.96 bcd 1.01 abcd 0.94 bcd 0.90 cd 0.93 bcd 0.94 bcd 0.97 abcd 0.96 abcd 0.91 cd 1.11 ab 0.98 abcd 1.15 a 0.93 bcd 1.07 abc 0.90 cd 1.00 abcd 0.99 abcd 0.84 d

a

-1

-1

-1

-1


elements in wheat straw were similar to those measured in corn stover, although the total amount of each removed with straw harvest is less because less straw is produced per hectare. The average of 6.6-6.7 Mg ha-1 corn stover yield19 is approximately 3 times the average straw yield estimated for the Pacific Northwest.1 With the exception of Zn, the quantities of micronutrients (Ca, Mg, Cu, Fe, Mn, and Zn) were greater in these straws than those measured in corn stover.19 The costs of fertilizers, particularly N, which is dependent upon natural gas markets, has been volatile during recent years, and consequently, the cost of replacing these nutrients must be calculated on the basis of market prices. Elemental concentrations in straws frequently did not correlate with the differences in soil concentrations of the respective elements measured at each location. For example,

Ca concentrations in soil from the Corvallis site were less than half of those measured in Moro and Pendleton soils (Table 1), yet straws produced at Corvallis generally contained greater levels of Ca than those produced at the other sites. In contrast, the concentration of K in soil at Corvallis was greater than that measured at the other two sites, yet straws produced at Corvallis in general contained less K than those produced at Pendleton. The soil Mn concentration at Corvallis was twice that measured at the other sites, yet straw concentrations of Mn produced at all three sites were similar. The soil Si concentration was greatest at Corvallis, but the range of Si in straw was similar at all three sites. Soil P concentrations generally correlated with straw P concentrations. Many straws produced at Corvallis contained greater concentrations of P than those produced at Moro and Pendleton. 2025

Energy Fuels 2010, 24, 2020–2027

: DOI:10.1021/ef901181h

El-Nashaar et al.

Table 9. Mean (n = 3) Concentrations of Selected Minerals in Combine Residues of 20 Winter Wheat Collected from Moro, OR (Sherman County)a element wheat cultivars Brundage 96 Cara Xerpta ORCF-103 Gene Skiles UICFLambert Madsen Masami Goetze ORCF-101 ORCF-102 ORSS-1757 Rod/ Tubbs06 Simon Stephens Tubbs Tubbs06 Weatherford Westbred 528 a

As (mg kg-1)

B (mg kg-1)

Cl Cd Cu Fe Mn Mo Ni (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1)

Si (mg kg-1)

Zn (mg kg-1)

12.3 a 12.8 a 13.4 a 11.9 a 13.3 a 12.8 a 12.3 a

59.9 abcde 60.5 abcd 58.1 abcdef 50.7 degf 51.6 cdefg 67.7 a 52.2 bcdefg

2510 abcd 1488 bcd 1675 abcd 1663 abcd 2395 abcd 1983 abcd 2390 abcd

2.00 a 1.02 b 1.10 b 1.10 b 1.04 b 1.15 ab 1.14 ab

13.65 bc 9.16 bc 8.02 bc 9.92 bc 13.01 bc 15.17 ab 9.16 bc

250 a 155 bc 184 abc 241 ab 204 ab 252 a 167 abc

97.1 a 94.6 ab 87.2 abc 83.1 abcde 45.4 h 80.1 bcdef 68.4 efg

1.55 ab 1.44 ab 1.48 ab 1.46 ab 1.55 ab 1.57 ab 1.35 b

66.7 abcde 79.6 abc 66.4 abcde 83.0 abc 85.2 ab 79.0 abcd 59.2 bcde

14525 abcd 17807 abc 14597 abcd 18653 ab 18777 ab 17730 abc 12847 bcd

5.52 ab 4.57 abc 3.61 abc 4.95 abc 5.28 abc 5.76 a 3.82 abc

11.6 a 13.4 a 12.0 a 12.4 a 13.5 a 13.3 a 12.2 a

41.8 g 54.0 bcdefg 64.4 ab 53.6 bcdefg 50.8 defg 64.2 abc 47.2 fg

2837 abcd 3461 ab 889 d 3001 abc 3542 a 2203 abcd 1560 abcd

1.06 b 1.51 ab 0.99 b 0.89 b 1.08 b 1.27 ab 0.92 b

8.43 bc 10.48 bc 12.04 bc 7.31 c 7.62 bc 21.55 a 9.92 bc

160 abc 179 abc 149 bc 168 abc 97 c 149 bc 217 ab

74.7 cdefg 83.0 abcde 75.3 cdefg 74.9 cdefg 85.3 abcd 63.5 g 74.6 cdefg

1.33 b 1.69 a 1.34 b 1.32 b 1.42 ab 1.48 ab 1.46 ab

51.8 de 59.9 bcde 92.8 a 62.6 bcde 61.2 bcde 50.5 e 90.3 a

10780 d 12683 bcd 21053 a 13480 bcd 13011 bcd 10702 d 20157 a

3.17 bc 4.50 abc 4.17 abc 3.10 c 3.10 c 5.31 abc 4.76 abc

12.0 a 12.7 a 12.9 a 13.2 a 14.0 a 13.4 a

57.1 abcdef 62.3 abcd 47.0 fg 50.4 degf 47.4 efg 56.6 abcdef

2130 abcd 2518 abcd 1660 abcd 1377 cd 1467 bcd 1774 abcd

1.08 b 1.00 b 1.04 b 1.21 ab 1.00 b 0.93 b

10.49 bc 8.50 bc 7.13 c 8.54 bc 8.35 bc 8.04 bc

194 ab 190 abc 173 abc 155 bc 148 bc 227 ab

76.5 cdefg 71.2 defg 67.9 fg 71.4 defg 66.6 fg 81.4 bcdef

1.46 ab 1.32 b 1.44 ab 1.34 b 1.46 ab 1.53 ab

67.2 abcde 69.0 abcde 56.4 cde 51.6 de 59.5 bcde 81.3 abc

14523 abcd 15390 abcd 11853 cd 10604 d 12530 bcd 17707 abc

4.68 abc 3.67 abc 3.53 abc 3.92 abc 3.46 abc 3.26 bc


Table 10. Mean (n = 3) Concentration of Selected Minerals in Combine-Harvested Residues of 20 Winter Wheat Cultivars Collected from Pendleton, OR (Umatilla County)a element wheat cultivars

Al (mg kg )

Ca (mg kg )

Mg (mg kg )

K (mg kg )

P (mg kg-1)

H (g kg-1)

C (g kg-1)

N (g kg-1)

S (g kg-1)


319 d 704 a 605 abc 474 abcd 510 abcd 406 cd 671 ab 439 bcd 482 abcd 442 bcd 456 bcd 501 abcd 469 abcd 462 abcd 407 cd 474 abcd 335 d 502 abcd 430 bcd 304 d

2337 abc 2490 ab 2306 abc 2404 abc 2044 bc 2106 abc 2587 ab 2172 abc 2187 abc 2065 abc 1996 bc 2008 bc 1989 bc 2150 abc 2036 bc 2653 a 1995 bc 2325 abc 1824 c 1999 bc

1682 a 1384 abcd 1336 abcd 1679 a 1158 bcd 1269 abcd 1616 ab 1375 abcd 1667 a 1176 bcd 1137 cd 1583 abc 1225 abcd 1450 abcd 1369 abcd 1001 d 1264 abcd 1529 abc 1451 abcd 1442 abcd

19590 ab 18637 ab 15333 ab 19980 ab 19487 ab 18237 ab 13057 b 17140 ab 18063 ab 17700 ab 17720 ab 20890 ab 19637 ab 16370 ab 17647 ab 18467 ab 16230 ab 18497 ab 20267 ab 22043 a

424 a 300 ab 401 ab 339 ab 229 b 328 ab 266 ab 305 ab 405 ab 308 ab 283 ab 331 ab 249 ab 291 ab 317 ab 287 ab 248 ab 309 ab 364 ab 332 ab

43.8 abcd 41.6 cde 42.9 bcde 42.6 bcde 40.3 de 39.4 e 44.5 abc 46.1 ab 42.9 bcde 41.2 cde 42.9 bcde 42.6 bcde 42.2 cde 42.3 cde 42.9 bcde 47.0 a 44.1 abcd 41.4 cde 41.9 cde 41.1 cde

384 abcd 405 abc 412 ab 394 abcd 381 bcd 392 abcd 394 abcd 391 abcd 391 abcd 410 ab 383 abcd 395 abc 399 abc 419 a 397 abc 358 d 419 a 372 cd 397 abc 412 ab

6.61 abcd 6.28 cd 6.34 bcd 6.67 abcd 6.53 abcd 6.62 abcd 6.35 bcd 6.65 abcd 6.95 abc 5.94 d 6.37 bcd 6.41 abcd 6.58 abcd 5.96 d 6.48 abcd 7.28 a 5.95 d 7.17 ab 6.73 abcd 6.10 cd

0.95 a 0.97 a 0.88 a 0.99 a 0.87 a 0.83 a 1.06 a 0.92 a 0.86 a 0.96 a 1.02 a 0.93 a 0.97 a 0.95 a 1.04 a 0.93 a 1.01 a 0.80 a 0.95 a 0.88 a

a

-1

-1

-1

-1


Previous work has shown that silicon is not equally distributed within wheat straw components.20 Accordingly, we quantified mineral composition in wheat stubble collected separately from the straw exiting the harvester from a select group of cultivars produced at the Pendleton site. These analyses showed significant differences in elemental composition among the cultivars used in this study, including greater than 2-fold difference in silicon content (Table 5). The magnitude of differences in silicon content between combine residues and stubble varied considerably among the cultivars, but in most cases, stubble silicon content was less than that

measured in the combine residue. The complete panel of elements was analyzed in the stubble samples, but only a subset representing those with significant differences are presented in Tables 4 and 5. Other studies that quantified elemental contents of grasses related to wheat have found similar quantities of these elements measured in this study.21-23 The quantities of Fe measured in these wheat cultivars were similar to those measured in rice and wheat straws in one study21,22 (21) Monti, A.; Di Virgilio, N.; Venturi, G. Biomass Bioenergy 2008, 32, 216–223. (22) Raveendran, K.; Ganesh, A.; Khilar, K. C. Fuel 1995, 74, 1812– 1822. (23) Fahmi, R.; Bridgwater, A. V.; Darvell, L. I.; Jones, J. M.; Yates, N.; Thain, S.; Donnison, I. S. Fuel 2007, 86, 1560–1569.

(20) Hess, J. R.; Thompson, D. N.; Hoskinson, R. L.; Shaw, P. G.; Grant, D. R. Appl. Biochem. Biotechnol. 2003, 105-108, 43–51.

2026

Energy Fuels 2010, 24, 2020–2027

: DOI:10.1021/ef901181h

El-Nashaar et al.

Table 11. Mean (n = 3) Concentration of Selected Minerals in Combine Residues of 20 Winter Wheat Cultivars Collected from Pendleton, OR (Umatilla County)a element wheat cultivars Brundage 96 Cara Xerpta ORCF-103 Gene Skiles UICFLambert Madsen Masami Goetze ORCF-101 ORCF-102 ORSS-1757 Rod/ Tubbs06 Simon Stephens Tubbs Tubbs06 Weatherford Westbred 528 a

B Cl Cd Cu Fe Mn Mo As (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1) (mg kg-1)

Ni (mg kg-1)

Si (mg kg-1)

Zn (mg kg-1)

13.3 a 13.6 a 11.9 ab 13.5 a 13.7 a 12.2 ab 13.5 a

52.0 bcd 70.1 a 51.7 bcd 48.5 cd 44.4 d 64.7 ab 54.2 abcd

1130 ab 1155 ab 1323 ab 1334 ab 949 ab 773 ab 949 ab

0.87 a 1.08 a 0.88 a 0.89 a 0.76 a 0.76 a 1.08 a

8.08 c 15.7 bc 16.4 ab 16.5 ab 16.0 b 10.9 bc 24.2 a

148 c 332 a 162 c 135 c 162 c 184 bc 248 b

106.0 a 92.9 abc 94.1 abc 90.5 abcd 41.2 f 74.9 cde 88.1 abcd

1.38 bcd 1.36 bcd 1.41 bcd 1.38 bcd 1.30 cd 1.66 ab 1.35 bcd

102.8 cd 107.5 bcd 101.9 cd 102.1 cd 115.0 bcd 103.0 cd 135.9 a

22293 bcd 24673 bcd 21990 cd 23150 bcd 24350 bcd 21793 cd 30903 a

4.81 bcde 9.04 ab 8.56 abc 7.10 abcde 5.76 bcde 4.58 cde 10.17 a

12.4 ab 11.5 ab 11.7 ab 11.4 ab 14.3 a 12.14 ab 12.9 a

48.5 cd 55.6 abcd 50.3 bcd 57.0 abcd 46.9 cd 61.6 abc 52.5 bcd

704 ab 1745 a 699 b 914 ab 1649 ab 740 ab 1517 ab

0.89 a 0.79 a 0.99 a 0.78 a 0.95 a 0.88 a 0.84 a

11.4 bc 11.9 bc 13.5 bc 11.6 bc 15.9 bc 13.9 bc 11.8 bc

195 bc 155 c 198 bc 146 c 142 c 140 c 146 c

76.8 bcde 98.4 ab 84.7 abcde 63.9 e 97.2 abc 69.9 de 75.9 cde

1.35 bcd 1.26 cd 1.45 abcd 1.31 cd 1.72 a 1.45 abcd 1.41 bcd

114.9 abcd 101.4 cd 122.5 abc 96.3 d 97.0 d 103.3 cd 107.4 bcd

24210 bcd 22303 bcd 27060 abc 21070 cd 22563 bcd 22473 bcd 23363 bcd

4.90 bcde 6.21 abcde 5.13 bcde 5.13 bcde 8.10 abcd 6.36 abcde 5.67 bcde

11.1 ab 12.3 ab 9.2 b 13.7 a 11.4 ab 12.1 ab

45.7 cd 48.2 cd 49.5 bcd 47.2 cd 44.4 d 47.8 cd

967 ab 749 ab 707 ab 946 ab 1246 ab 1593 ab

0.90 a 0.83 a 0.85 a 0.85 a 0.85 a 0.76 a

10.2 bc 14.7 bc 10.3 bc 12.8 bc 12.0 bc 9.1 bc

161 c 154 c 160 c 151 c 155 c 123 c

85.9 abcde 70.2 de 66.2 e 84.8 abcde 75.6 cde 76.1 bcde

1.30 cd 1.54 abc 1.30 cd 1.40 bcd 1.30 cd 1.15 d

113.2 abcd 131.9 ab 97.9 cd 109.6 bcd 93.1 d 90.6 d

24723 bcd 28083 ab 21270 cd 24087 bcd 20173 d 19577 d

4.96 bcde 6.20 abcde 3.36 e 6.24 abcde 5.85 bcde 4.02 de


but much greater than those measured in many of the Lolium species analyzed in another study.23 The differences in Fe content may be due to genotypic differences between the species tested or by the digestion approach used to disrupt the tissues. Our study used HF digestion, whereas the Lolium tissues were digested with nitric acid. It is likely that both genotypic differences and contrasting approaches to tissue digestion impacted the apparent Fe content in these studies. Conclusions

study, and some of the differences were dependent upon the location at which the wheat was produced. On average, straw harvest removed 6.42 g of N, 0.4 g of P, and 14 g K kg-1 of straw. If straw below the flag leaves was harvested, an additional 6.43, 0.23, and 17.8 g of N, P, and K, respectively, were removed from the production system. These apparent genotypic differences suggest that selections for lower concentrations of elements, such as Si, K, and Cl, that are undesirable for thermochemical conversion technologies could enhance the utility of wheat straw for these conversion approaches.

Genotypic differences in the concentrations of elements existed among the winter wheat cultivars analyzed in this

Acknowledgment. We thank Machelle Bamberger for excellent technical help in performing the ICP analyses.

2027

Genetic Variability of Elemental Concentration in Winter Wheat Straw

Recommend Documents