ORNUSub/85-27412/5&P1 

EVALUATION OF POTENTIAL HERBACEOUS BIOMASS 

CROPS ON MARGINAL CROP LANDS: 1) AGRONOMIC POTENTIAL 

Final Report 1985-1989 

J.H.Chemey 

KD.Johnson 

J.J. Volenec 

E.J. Kladivko 

D.KGreene 

Department of Agronomy 

Purdue University 

West Lafayette, IN 47907 

Date Published- July. 1990 

Research supported by 

Biofuels Systems Division 

Office of Transportation Technologies 

Activity No. EB 24 01 00 0 

Report prepared by 

Department of Agronomy 

Purdue University 

West Lafayette, Indiana 47907 

under Subcontract 19X-27412C 

for 

Herbaceous Energy Crops Program 

Environmental Sciences Division 

OAK RIDGE NATIONAL LABORATORY 

Oak Ridge, Tennessee 37831-6285 

operated by 

MARTIN MARIETTA ENERGY SYSTEMS, INC. 

for the 

U.S. DEPARTMENT OF ENERGY 

under contract DE-AC05-840R21400 

TABLE OF CONTENTS 

TABLE OF CON1ENTS ................................................................................................................ . 

LIST OF FIGURES ........................................................................................................................ .. 

LIST OFT ABLES ........................................................................................................................... .. 

ABSTRACT ...................................................................................................................................... .. 

INl'RODUCTION ........................................................................................................................... . 

OBJECTIVES ................................................... : ............................................................................... . 

PROCEDURES ............................................................................................................................... .. 

Species Selection ........................................................................................................................ .. 

Site Selection .............................................................................................................................. .. 

Crop Management ...................................................................................................................... . 

Perennial Crops .................................................................................................................... .. 

Doublecropping Sorghum and Winter Rye ...................................................................... . 

Interseeding of Sorghum into Perennial Grasses ............................................................ .. 

Photoperiod Sensitive and Insensitive Sorghums ............................................................ . 

Yield and Persistence of Southern U.S. Species .............................................................. . 

Big Bluestem compared to Switchgrass ............................................................................. . 

Compositional Analyses ........................................................................................................... .. 

Nonstructural Components ................................................................................................. . 

Structural Components ....................................................................................................... .. 

Soil Analysis .......................................................................................................................... .. 

RESULTS AND DISCUSSION .................................................................................................... . 

Soils .............................................................................................................................................. .. 

Objective 1 - Perennial Grass and Legume Production ........................................................ . 

Production Potential of Grasses ......................................................................................... . 

Production Potential of Legumes ....................................................................................... . 

Plant Composition ................................................................................................................ . 

Hemicellulosic Sugars and Phenolic Monomers .............................................................. . 

Objective 2 - Production of Sorghum Doublecropped with Winter Rye .......................... .. 

Winter Annual Rye ............................................................................................................... . 

Sweet Sorghum and Sorghum-sudangrass ......................................................................... . 

Objective 3 - Production of Sorghum Interseeded into Perennial Grasses ...................... .. 

Objective 4 - Production Potential of Photoperiod-Sensitive and Insensitive Sorghums 

Plant Composition ................................................................................................................ . 

Objective 5 -Yield and Persistence of Southern U.S. Species ............................................ .. 

Objective 6 - Relative Productivity of Switch grass and Big Bluestem ................................ . 

SUMMARY AND CONCLUSIONS ............................................................................................ . 

REFERENCES ................................................................................................................................ .. 

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UST OF FIGURES 

1 Switchgrass yield response to nitrogen fertilization (0, 50, 100, 150, and 200 

kg N ha-1 ). Means of four replicates and one location in 1986, three locations 

in 1987, and four locations in 1988 and 1989..................................................................... 12 

2 Tall fescue yield response to nitrogen fertilization (0, 50, 100, 150, and 200 

kg N ha-1 ). Means offour replicates and two locations in 1986 and four 

locations in 1987-89............................................................................................................... 13 

3 Reed canarygrass yield response to nitrogen fertilization (0, 50, 100, 150, and 

200 kg N ha-1). Means offour replicates and one location in 1986, three 

locations in 1987, and four locations in 1988 and 1989.................................................... 13 

4 Switchgrass composition, 1988 ............................................................................................ 17 

5 Reed canarygrass composition, Harvest Date 2, 1988...................................................... 17 

6 Birdsfoot trefoil composition, Harvest Date 2, 1988........................................................ 18 

7 Alfalfa composition, Harvest Date 3, 1988 ........................................................................ 18 

8 Winter annual rye yield response to nitrogen fertilizer carryover from 

applications to sorghum in previous years ........................................................................ . 

9 Sweet sorghum yield response to nitrogen fertilization (0, 50, 100, and 150 

kg N ha-1) averaged over four replicates, four locations, and two tillage 

19 

treatments............................................................................................................................... 22 

10 Sweet sorghum ('M81E') stover composition, 1988......................................................... 26 

11 Sorghum ('V2319') stover composition, 1988................................................................... 26 

v 

LIST OF TABLES 

1 Aggregate stability (mean weight diameter, MWD) of soil as influenced by 

location and species............................................................................................................... 10 

2 Aggregate stability (mean weight diameter, MWD) of soil in doublecrop sorghum 

plots as influenced by location, nitrogen fertilization, and tillage for 1989.................. 11 

3 Dry matter yield of alfalfa and birdsfoot trefoil as influenced by year and 

location.................................................................................................................................... 15 

4 Dry matter yield of sweet sorghum and sorghum-sudangrass as influenced by 

species and tillage................................................................................................................... 21 

5 Dry matter yield of sweet sorghum and sorghum-sudangrass interseeded into 

tall fescue as influenced by herbicide application and sorghum species in 1987.......... 23 

6 Dry matter yield of sorghum as influenced by species and cutting management......... 25 

7 Dry matter yield of warm-season perennial grasses, alfalfa, and sericea 

lespedeza in 1989.................................................................................................................... 28 

8 Dry matter yield of big bluestem and switchgrass at the Purdue Agronomy Farm...... 29 

vii 

ABSTRACf 

Management of herbaceous biomass crops must be investigated concurrently with the 

development of cost-effective conversion processes. Our objective was to evaluate the agronomic 

feasibility of several combinations of species and management systems for producing herbaceous 

biomass on sites ranging from good to marginal cropland. Soil organic matter and aggregate 

stability were not adversely affected by any of the management options. 

Of the perennial grasses and legumes investigated, switchgrass showed the most potential as a 

biomass candidate. It has minimum fertilizer inputs, is very persistent, and is effective in reducing 

soil erosion. Sorghum double-cropped with winter annual rye was very productive, but required 

more inputs than switchgrass. Interseeding sorghum into perennial grasses was not a viable option, 

due to its great dependence on environmental variables. Photoperiod-sensitive and hybrid 

sorghums able to utilize an entire growing season were very productive, with yields up to 39 Mg hal. Two harvest per season resulted in low yields, such that lodging resistance must be incorporated 

into desirable genotypes through breeding, instead of using multiple harvests to prevent lodging. 

Plant composition was greatly affected by species, with a wide range in composition across sorghum 

genotypes. 

Of all species evaluated, switch grass and sorghum have the greatest biomass potential, and 

both of these species can be improved to produce higher yields of a more desirable chemical 

composition through plant breeding. 

CHERNEY, J.H., K.D. JOHNSON, J.J. VOLENEC, E.J. KLADIVKO, and D.K. GREENE. 

Evaluation of Potential Herbaceous Energy Crops on Marginal Croplands: 1) Agronomic Potential. 

1990. ORNL/Sub/85-2741/5&P1. Oak Ridge National Laboratory, Oak Ridge, Tennessee. 43 pp. 

ix 

INTRODUCTION 

As technology for economically converting biomass from herbaceous crops to energy is 

developed, methods for cost-effective production of herbaceous biomass crops need to be 

investigated. Our overall goal was to evaluate the agronomic and economic feasibility of several 

combinations of species and management systems for producing herbaceous biomass on a range of 

cropland sites, from good to marginal cropland. This report concerns the agronomic potential of 

producing herbaceous biomass. 

Although grain crop residues are a potential biomass source, estimates indicate that in the U.S. 

only 80 million tons of crop residues can be harvested annually without creating a serious soil 

erosion problem (OTA, 1980). Erosion currently is a serious problem on marginal lands that are 

being row cropped. Marginal lands can be grouped into two types. The first is land that is tillable 

on an annual basis, but soil and/or climate limitations restrict its usefulness for grain crops. It is 

desirable to provide ground cover throughout the year on this type of land in order to avoid sheet 

and rill erosion. The second type of marginal land includes lands which are not tillable on an annual 

basis due to erosive, rough, or hilly terrain. Herbaceous crop species under consideration for 

potential biomass utilization should produce economically acceptable yields while at the same time 

minimizing soil erosion. Forage crops are ideal for this purpose. 

There is a broad range in diversity among forage crops. Forages may be annual or perennial in 

habit, cool season or warm season, and grass or legume. Some annual species have a short growing 

season such that they can be preceded by a winter annual species, thus producing two crops in one 

season. It also is possible to interseed an annual species into a dormant perennial species to 

increase annual production. Forage crops fit well into a biomass production scheme. They are 

adapted and presently grown on marginal as well as productive land, and their production 

technology is familiar to farmers. Labor and machinery needs fit well with other farming 

operations, and equipment for harvest and storage of these forage crops is available on most farms. 

Crop management practices for forage species have stressed a high quality product for 

livestock feed. Previous research in this area is not applicable to biomass production, since quality 

and yield are inversely related (Cherney and Marten, 1982). Due to inherent variation in marginal 

land sites, several locations and environmental conditions are necessary to evaluate the agronomic 

feasibility of various cropping systems. 
2 

Chemical composition of herbaceous crops will become important when one or more 

economically feasible conversion processes become available for herbaceous crops. Forage plants 

consist of a nonstructural and a structural component, and have a composition very different from 

woody biomass species. Soluble materials include protein, sugars, and pectin. Structural material 

(fiber) can be separated into its major components including cellulose, hemicellulose, and lignin. 

Since the ~ideal" composition of a biomass crop is not known, it is necessary to determine chemical 

composition of all potential biomass crops. This information will be very important in selecting 

species to fit various conversion options. 

OBJECTIVES 

Our overall agronomic objective was divided into six specific objectives: 

1. Determine the biomass yield and chemical composition of tall fescue (Festuca arundinacea 

Schreb.), reed canarygrass (Phalaris arundinacea L.), switchgrass (Panicum virgatum L.), 

alfalfa (Medicago sativa L.), and birdsfoot trefoil (Lotus corniculatus L.) when grown under 

several levels of fertilization on marginal sites. 

2. Determine the biomass yield and chemical composition of winter rye and sorghum 

[Sorghum bicolor (L.) Moench.] in a double-cropping system. 

3. Determine the feasibility of interseeding sorghum into tall fescue or reed canarygrass sod 

with and without herbicides, after biomass of the cool-season grasses has been removed in 

the spring. 

4. Determine the production potential of photoperiod-sensitive and insensitive sorghums 

compared to sweet sorghum, sorghum-sudangrass, and corn (Zea mays L.). 

5. Determine the persistence and yield potential of sericea lespedeza ~pedeza cuneata 

(Dumont) G. Don], weeping lovegrass [I:;ragrostis curvula (Schrad.) Nees], and big 

bluestem (Andropogon gerardii Vitman), compared to switchgrass and alfalfa. 

6. Compare the relative productivity of big bluestem and switchgrass in established stands. 
3 

PROCEDURES 

Species Selection 

We selected grass and legume crops representative of a large range of species. Cool-season 

perennial grasses produce a majority of their biomass in the spring, with a significant amount of 

growth in the fall. Tall fescue and reed canarygrass were chosen from this category for the following 

reasons. Tall fescue is already established on millions of acres in the Midwest/Lake States area, and 

represents a commonly grown species. Reed canarygrass is less commonly grown, but is extremely 

well adapted to marginal sites. It has seen limited use as livestock feed, because herbage alkaloids 

make it unpalatable. Use of this grass is increasing, with the recent release of low alkaloid cultivars. 

Reed canarygrass has outproduced other perennial grasses on marginal lands two fold (Cherney et 

al., 1986). It is adapted to wet and dry conditions, and has produced high yields from southern 

Indiana (Cherney et al., 1986) to Northern Minnesota (Marten et al., 1980). 

Warm-season perennial grasses have excellent potential for producing biomass, since they have 

the c4 photosynthetic pathway and are very productive during the warm, dry summer months. 

These grasses complement the harvest of the cool-season grasses because their harvest is at a 

different time during the growing season. This may be an important economic consideration for the 

biomass crop producer and the biomass conversion plant. We selected pvitchgrass for this study, 

since it is capable ofvery high yields with a single harvest per year and is a warm-season grass 

adapted to the entire Midwest/Lake States region. It is a vigorous grass which will produce better 

growth on droughty, infertile, eroded soils than most grasses, and has been used extensively for 

erosion control (}:Ieath et al., 1985). 

Perennial legumes can fix their own nitrogen, and have the advantage of not requiring an 

expensive nitrogen fertilizer source. Legumes also are useful for control of erosion. A disadvantage 

of legumes is that most need to be periodically reseeded. Alfalfa and birdsfoot trefoil were included 

in the study as representatives of the perennial legume group. Alfalfa is generally very productive 

on good agricultural sites. Birdsfoot trefoil is less productive, but is more tolerant of acid or wet 

soil conditions, and has the ability to reseed itself under the proper management. 

Annual grasses, such as sorghum, can be very productive, but require high management inputs 

and can have serious erosion potential. A method of reducing erosion is to doublecrop two species, 

thus maintaining a cover on the soil surface for most of the year. Therefore, we evaluated a 
4 

sorghum·sudangrass hybrid and sweet sorghum as summer annual grasses doublecropped with 

winter annual rye. 

Another method of maximizing biomass production while minimizing erosion potential is 

intercropping, or growing two crops together simultaneously. The two crops must be compatible, 

and the crops must be managed such that one or the other is not eliminated from the stand. Cool· 

season grasses, although productive in the spring and fall, are usually semi .dormant during the hot 

summer months. We no· till planted sorghum into the cool-season grasses in order to increase 

biomass production of a cool-season grass stand during the summer months. 

Photoperiod-sensitive genotypes will generally not set seed under Midwest conditions, but will 

continue to grow vegetatively until experiencing freezing temperatures. Therefore, yield can be 

maximized by utilizing the entire growing season. Lodging potential must also be evaluated, since 

some genotypes reach a height of 6 meters. 

Two species which are very productive in the southern U.S. are sericea lespedeza and weeping 

lovegrass. Their area of adaptation extends to the southern boundary of the Midwest. Our goal was 

to determine if these species would persist in Indiana, and if they would be as productive as in the 

southern U.S. 

Based on past studies, the only warm-season perennial grass which might be as productive as 

switchgrass in the Midwest is big bluestem. We used established stands ofswitchgrass and big 

bluestem to compare their relative productivities. 

Site Selection 

Five sites were selected in Indiana to represent a range from good to marginal cropland. 

Organic matter content of the soil from the four sites ranged from 1.5 to 3.7% of soil dry weight. 

Site 1 is located in west central Indiana at the Throckmorton Purdue Agricultural Center (TFLA 1). It is located on a soil which has a minimum of restrictions to agricultural production, and 

has a slope near zero. The soil type is a Sidell ('l)pic Argiudoll, fine-silty, mixed mesic) silt loam 

with a 0 to 2% slope. The previous crop on this site was conventionally-tilled corn. It is considered 

very good to excellent agricultural land, and is representative of the large acreage of land in the 

Midwest dedicated to row-crop farming. 
5 

Site 2 is also located in west central Indiana at the Throckmorton Purdue Agricultural Center 

(T-SLOPE) and is on a similar soil type as Site 1 with less organic matter, and a previous crop of 

conventionally-tilled com Its major restriction to production is that it is on a 6 to 8% slope with 

erosion problems. 

Site 3 is located at the southeastern Indiana Purdue Agricultural Center (SEPAC) on a soil 

very similar to areas in southern Ohio and southern Illinois. The soil type is a Cincinnati (Typic 

Fragiudalf, fine-silty, mixed, mesic) silt loam. The soil has a fragipan which makes it difficult to 

drain and restricts rooting depth. The 8 to 10% slope creates severe erosion problems due to the 

poorly structured silt loam surface. The previous crop was conventionally-tilled corn. 

Site 4 is located in a very hilly region of southcentral Indiana at the Southern Purdue 

Agricultural Center (SIP A C). The soil type is a Zanesville (Typic Fragudalf, fine-silty, mixed mesic) 

silt loam. 'This area is similar in topography to southwest Wisconsin and other hilly areas in the 

Upper Great Lakes Region. The silt loam soil has a dense, brittle fragipan and an 8 to 12% slope 

with prior erosion. The slope and soil characteristics make this poor cropland. Tall fescue was the 

previous crop on this site. 

Site 5 is located in west central Indiana at the Purdue Agronomy Farm on good agricultural 

soil with 0 to 2% slope. The soil type is Chalmers (Typic Haplaquoll) silty clay loam. This site was 

chosen for comparison of switchgrass and big bluestem in 1988 (Objective 6), since both had been 

previously established at this site. 

Perennial Crops. Tall fescue ('Forager'), reed canarygrass ('Venture'), switchgrass ('Cave-inRock'), alfalfa ('Hi-Phy'), and birdsfoot trefoil ('Fergus') were planted at all four sites in the spring 

of 1985. A randomized complete block design with four replicates was used, with a split plot 

arrangement for fertilizer treatments. Individual plot size was 2.43 X 6.10 m. Establishment of 

grasses at some locations failed in 1985, and they were replanted in 1986. 

In 1986-89 established grasses received 0, 50, 100, 150, or 200 kg N ha·1 in the spring. Tall 

fescue and reed canarygrass were harvested in late May and in early September. Switchgrass was 

harvested once in mid-July. In 1989, switchgrass regrowth was sufficient enough for a second 

harvest after first frost. Legume stands were fertilized with 0, 100, or 200 kg potassium ha •

1 in late 
6 

March, since potassium is usually the most limiting element for legume biomass production. Alfalfa 

was harvested three times per year, in early June, mid-July and late August. Birdsfoot trefoil was 

harvested twice, in early June and late August, allowing reseeding to occur. Harvesting was 

accomplished with a flail-type harvester. 

Doublecropping Sorghum and Winter Rye. Sorghum-sudangrass ('FFR-201') and sweet 

sorghum ('M81E') were conventionally sown in mid-May, 1985 using a randomized complete block 

design with four replicates. In succeeding years (1986-88) one half of the plots were conventionally 

sown and one half were no-till sown. Four rates of nitrogen fertilizer, 0, 50, 100, or 150 kg N ha·1 

were applied at seeding. There was a split-split plot arrangement of the treatments, with tillage as 

the whole plot, species as the sub-plot and fertilizer as the sub-sub-plot. Herbicide (2,4-DB) was 

applied for the control of broadleaf weeds as necessary. Sorghum-sudangrass was harvested once in 

early September at a mature grain stage, and sweet sorghum was harvested once in early October at 

a flowering to early grain stage. Yields included both grain and stover components of plants cut 5 

em above the soil surface. 

Winter annual rye was no-till seeded into the sorghum stubble in early October 1985-88, and 

50 kg N ha·1 was applied to the rye crop in the spring. Rye was harvested with a flail harvester at 

anthesis in mid-May and sorghum was either conventionally sown after tillage or no-till sown into 

the rye stubble. 

lnterseeding of Sorghum into Perennial Grasses. In the spring of 1986 and 1987 after the 

harvest of tall fescue and reed canarygrass, sorghum-sudangrass and sweet sorghum were no-till 

sown into the established perennial grass sods with the addition of 0, 100, or 200 kg N ha ·

1. One 

half of the plots were treated with paraquat to delay any growth of the perennial grass until the 

sorghum had become established. As with the other experiments, the individual plot size for each 

treatment combination was 2.43 X 6.10 m and the design was a randomized complete block with 4 

replicates. Treatments were arranged in a sp1it-split-split plot, with sorghum species as the sub-plot, 

herbicide treatment of the perennial grass sod as the sub-sub-plot, and nitrogen fertilizer as the subsub-sub-plot. Sorghum was hand-harvested in early September and this was followed by harvest of 

the perennial grass with a fail harvester. 

Photoperiod Sensitive and Insensitive Sorghums. Areas at T-FLAT and SIPACwere selected 

for establishing this study, and P, I<, and lime were applied as needed. Both sites were 

conventionally tilled in early May, 1988 and 1989. Sweet sorghum, sorghum-sudangrass, several 
7 

tropical sorghums and one hybrid forage sorghum were sown in three replicates of four row, 6.1 m 

plots at both locations in 1988. Two rates of N fertilization (100 or 200 kg N ha* 1) were applied. 

Hybrid corn ('Pioneer 3475') was sown to measure corn grain potential at the sites. Sorghumsudangrass was sown with a 20.3 em row spacing and harvested twice during the season in an 

attempt to increase its production. Since sorghum-sudangrass has not been competitive with sweet 

sorghum when cut once and doublecropped with rye, it was managed to utilize more of the growing 

season. All other species were harvested once in early October, prior to a killing frost. For analysis, 

species were the whole plot, with nitrogen rates as a subplot. 

In 1989, sorghum-sudangrass was not sown, but more hybrid forage sorghums were added to 

the study. Also in 1989, all sorghum species were harvested either one to two times. Two-cut 

sorghums were harvested in July and in early October, one-cut sorghums were harvested in early 

October. For analysis, harvest management was the whole plot, with species as a subplot, and 

nitrogen rate as a sub-subplot. 

Yield and Persistence of Southern U.S. Species. Areas at T-FLAT and SIP AC were selected, 

and P, K, and lime were applied as required by soil test. Sites were conventionally tilled and alfalfa 

('Hi*phy') and sericea lespedeza ('Serala') were sown in mid-April, 1988. The first week of May 

switchgrass ('Cave-in-Rock'), big bluestem ('Kaw'), and weeping lovegrass ('Ermelo') were sown. 

Alfalfa, switchgrass, and big bluestem were sown for comparison with the two southern U.S. species. 

Plot areas were irrigated at both sites to aid establishment. All species were successfully established 

at T-FLAT, but weeping lovegrass and big bluestem needed to be resown in the spring of 1989. 

Three nitrogen rates were applied to grasses (0, 100, and 200 kg N ha-l). In 1989, alfalfa and 

weeping Iovegrass were harvested three times, switchgrass and sericea lespedeza were harvested 

twice, and big bluestem was harvested once. 

Big Bluestem Compared to Switchgrass. Five-year-old stands of'Kaw' big bluestem and 'Cavein-Rock' switch grass at the Purdue Agronomy Farm were used for this portion of the study, starting 

in 1988. Plot areas were fertilized with 0, 100, or 200 kg N ha-l. Switchgrass was harvested once in 

late July or early August, 1988 and 1989, and big bluestem was harvested once per season two weeks 

later than switch grass. Species were considered whole plots for statistical analysis, with nitrogen 

rates as subplots. 
8 

Compositional Analyses 

Samples of herbage were collected and dried at 6fP C to determine dry matter content for 

calculation of yields. Subsamples were ground and analyzed for structural and nonstructural 

components. Compositional analyses are reported on a 105° C dry weight basis. 

Nonstructural Components. Nitrogen content of samples was determined using a microKjeldahl technique. Nonstructural carbohydrates were extracted with deionized water from fructanstoring species (cool-season grasses, including rye), or were hydrolyzed using amyloglucosidase for 

starch-storing species (legumes, switchgrass, and sorghums). In 1988, pectin content was 

determined. For pectin analysis, samples (0.1 g) were incubated overnight at 4()0C with pectolyase 

(5 mg) in 20 mL of pH 4.6 acetate buffer. Standard reagents (for a uronic acid analysis) were added 

and readings were taken at 520 nm. Pectin content was determined based on galacturonic acid as a 

standard. All components were reported on a dry weight basis. 

Structural Components. The detergent fiber method was used to quantify (gravimetrically) 

concentrations of fiber and structural cell wall components. The neutral detergent fiber (NDF) 

procedure was used to separate fiber and soluble cell components (including pectin), and an acid 

detergent fiber procedure was used to remove hemicellulose from the fibrous neutral detergent 

residue. Lignin was oxidized and removed with permanganate, and samples were ashed to 

determine cellulose by difference. 

In 1988, plant silica values were determined using a modified sequential fiber procedure. 

Neutral detergent can not be used, since it solubilizes plant silica. Samples were treated with acid 

detergent, and residues were extracted with permanganate and then ashed. The ash was treated with 

40% HBr to remove anything remaining in the sample that was not silica (primarily other minerals). 

The sample was ashed a second time and silica content was determined as the remaining sample 

weight. 

Soil Analysis. Standard soil tests were taken each year to determine whether lime, phosphorus, 

or potassium addition was necessary. In 1985, 1987, and 1989 soil samples were taken for organic 

matter and aggregate stability analyses. Aggregate stability was determined using a wet sieving 

technique. Mean weight diameter was determined and is a measure of the average size of a waterstable aggregate. Statistical analyses presented were derived from separate analyses of variance by 

year. 
9 

RESULTS AND DISCUSSION 

Soils were fertilized as required by soil test recommendations throughout the study. One 

exception to this was the controlled application of potassium on legume plots. Organic matter 

values were reasonably stable throughout the study, averaging 37.3, 19.3, 15.7, and 22.7 g kg-1 dry 

soil forT-FLAT, T-SLOPE, SEPAC, and SIPAC, respectively. 

Soils were monitored for aggregate stability in 1985, 1987, and 1989 (Table 1). Aggregate 

stability is a measure of soil stability that is inversely proportional to erodibility. Aggregate 

stability, measured as mean weight diameter, improved at all three sites where corn had been the 

crop grown previous to our study. Aggregate stability did not improve at SIPAC, where the land 

had been in continuous tall fescue for many years prior to our study. Of the perennial crops grown, 

tall fescue and reed canarygrass resulted in significantly higher aggregate stability, with no difference 

between switchgrass, alfalfa, and birdsfoot trefoil. 

Doublecropping of sorghum and rye resulted in similar aggregate stability values as switchgrass 

(Table 2). High nitrogen fertilization resulted in lower aggregate stability, and no-till planting of 

sorghum resulted in higher aggregate stability than conventional tillage, as expected. 

Maintenance of soil stability is essential for reducing erosion problems and for maximizing 

crop productivity. These results indicate that perennial, sod-forming crops will tend to increase soil 

stability more than annual row crops. Sorghum doublecropped with rye, however, resulted in 

improved aggregate stability over conventional corn production. 

Objective 1 - Perennial Grass and Legume Production 

Production Potential of Grasses. In general, switchgrass (Fig. 1) produced more dry matter 

with one harvest per year than tall fescue (Fig. 2) or reed canarygrass (Fig. 3) with two harvests. 

Switchgrass and reed canarygrass were more difficult to establish, !nd were not well enough, 

..:etablished to measure yields at SIPAC until1988. In 1989, switchgrass regrowth in late fall was 

sufficient enough for a second harvest after a killing frost. This resulted in significantly larger yields 

for switchgrass in 1989, averaging over 16 Mg dry matter ha-l at SIPAC. The drought of 1988 

reduced yields to 20 to 30% of a normal year. 
Table 1. 

1985 

1987 

1989 

1989 

10 

Aggregate stability (mean weight diameter, MWD) of soil as 

influenced by location and species. 

Location 

T-FLAT T-SLOPE SEPAC SIPAC 

------------------------- mm ------------------------

0.65 0.73 0.71 1.95 

1.07 0.89 1.46 2.61 

2.42 1.79 1.70 2.21 

Species 

Alfalfa BFT Tall Reed Switch BLSDa 

fescue canarygrass grass 

------------------------------------ mm ------------------------------------

1.54 1.89 2.31 2.38 1.72 0.36 

a Bayes least significant difference (P approximately 0.05). 
• 

• 

.. 

Table2. 

11 

Aggregate stability (mean weight diameter. MWD) of soil in doublecrop sorghum plots as influenced by location. nitrogen fertilization • 

and tillage for 1989. 

Location 

T-FLAT T-SLOPE SEPAC SIPAC 

--------------------------------- mm ----------------------------------

1.89 1.95 1.16 1.44 0.46 

Nitrogen applied to Sorghum. kg N ha-l 

0 150 Significanceb 

----------- mm -----------

1.75 1.47 ** 

Tillage 

Conventional No-till Significanceb 

----------- mm ------------

1.17 2.04 ** 

a Bayes least significant difference (P approximately 0.05). 

b **Significant at P < 0.01. 
20 

18 

16 

•14 .c 

Ci.12 

:& 

.g-10 

! 8 

> 

6 

4 

2 

0 

12 

... 0 ........ 50.... . 100 .... 150 

>1 ..... ~ .... -.-

1986 1987 1988 1989 

Figure 1. Switchgrass yield response to nitrogen rertilization (0, SO, 100, 150, and 200 kg N 

ha •

1). Means or rour replicates and one location in 1986, three locations in 1987, and 

rour locations in 1988 and 1989. 

.. 

.. 
13 

20 ...... 0 50 ...... .. 100 . . . ......... 150 . . . 200. 

18 li l HH ...,..~H ... ... ... 

. . ·- ---

1986 1987 1988 1989 

Figure 2. Tall fescue yield response to nitrogen fertilization (0, 50, 100, 150, and 200 kg N ha •

1

). 

Means of four replicates and two locations in 1986 and four locations in 1988-89 . 

.. .. . .. .......... 100.... . 150 ............. 2.0.0 ... . 

~...,.,.,...., ...... ••••••• • •••••••••••• ««««««««< ... « "" 

1986 1987 1988 1989 

Figure 3. Reed canarygrass yield response to nitrogen fertilization (0, 50, 100, 150, and 200 kg N 

ha •

1). Means of four replicates and one location in 1986, three locations in 1987, and 

four locations In 1988 and 1989. 
14 

The yield response to nitrogen fertilization was predictable in tall fescue (Fig. 2) and reed 

canarygrass (Fig. 3). Switchgrass, however, required much less nitrogen for high yields, and even 

produced acceptable yields with no nitrogen fertilizer applied (Fig. 1 ). Some nitrogen fertilizer is 

necessary for high yields when switchgrass is harvested twice per year. Since N fertilization is a high 

cost input, the relatively large yields of switchgrass in one harvest with minimum fertilizer input give 

this grass a high potential as a biomass species. 

Production Potential of Legumes. Alfalfa yields were high on good cropland, but were much 

lower on marginal cropland sites (fable 3). Since alfalfa is drought resistant, yields were not as 

negatively affected in 1988 as in the perennial grasses. Alfalfa produced as much as 17 Mg dry 

matter ha -

1, but required three harvests and periodic insect control to achieve these yields. 

Birds foot trefoil produced considerably lower yields than alfalfa except at SIP AC (fable 3 ). Trefoil 

is more tolerant of less than optimum environmental conditions, and was not damaged by plant 

heaving during the spring as was alfalfa. Alfalfa also was damaged by deer grazing at SIP AC, 

resulting in lower harvested yields. 

Neither alfalfa nor birdsfoot trefoil responded to potassium fertilization at any of the four 

sites. Since legumes typically remove a large quantity of potassium from the soil, this lack of 

response was probably due to the high concentration of potassium initially present in the soil at all 

four sites. Although depletion of potassium leading to a yield response with potassium fertilization 

was expected, it did not occur. 

Plant Composition. Herbaceous biomass has a composition very different from woody biomass 

species. The composition also changes greatly as the plant matures, and composition of immature 

herbaceous plants is considerably different from the more mature plants harvested in this study. 

Boiling in neutral detergent with ethylenedinitrilo-tetraacetic acid (EDT A) removes soluble 

materials, including pectin, from the herbage. The remaining fiber (neutral detergent fiber, NDF) 

can be separated into its major components. Cellulose, hemicellulose, and lignin can be estimated 

gravimetrically. 

Crude protein concentration was estimated by multiplying the nitrogen concentration by 6.25 

(based on the average nitrogen content of a protein). Nonstructural carbohydrates (CHO) were 

determined, as well as pectin and silica on 1988 samples. The remaining unaccounted soluble dry 

matter was termed 'other solubles'. This component contains tannins and other soluble phenolics, 
15 

Table 3. Dry matter yield of alfalfa and birdsfoot trefoil as influenced by year 

and location. 

1986 

1987 

1988 

1989 

1986 

1987 

1988 

1989 

Alfalfa 

T-FLAT T-SLOPE SEPAC SIPAC 

----------------------------- Mg ha •

1 ----------------------------

14.56 13.19 9.29 7.89 1.97 

14.68 13.56 11.30 6.92 2.24 

17.36 13.28 9.98 1.62 2.78 

12.87 13.28 9.94 8.71 1.04 

Birdsfoot Trefoil 

T-FLAT T-SLOPE SEPAC SIPAC 

-------------------------------- Mg ha •

1 ---------------------------

3.96 5.28 7.31 6.21 1.21 

6.26 6.32 6.24 7.59 0.90 

8.03 

3.72 

6.31 

4.51 

5.88 

5.72 

5.25 

7.74 

1.41 

0.46 

a Bayes least significant difference (P approximately 0.05). 
16 

plant pigments, lipids, soluble minerals, and other components. 

Switchgrass is very high in fiber, over 700 g kg-1 dry weight. It has very little silica and pectin, 

with approximately equal amounts of lignin, crude protein, and soluble CHO (Fig. 4). Herbaceous 

grasses tend to have similar amounts of cellulose and hemicellulose, with relatively small amounts of 

lignin, compared to woody species. Tall fescue and reed canarygrass contained lower amounts of 

fiber, and were higher in crude protein, CHO, and silica, as compared to switchgrass (Fig. 5). Tall 

fescue was similar to reed canarygrass and the data is not shown. 

Alfalfa and BFrwere similar in composition (Fig. 6-7), and differed significantly from the 

grasses. Legumes typically contain twice as much cellulose as hemicellulose, and are higher in lignin 

and crude protein than grasses. They also are lower in total fiber than grass,es, with a large undefined 

neutral-detergent soluble component. Composition was not influenced by location or management 

treatment. 

Hemicellulosic Suzars and Phenolic Monomers. In 1988, samples were analyzed for neutral 

hemicellulosic sugars and alkali-labile phenolic monomers using high performance liquid 

chromatography. Glucose and xylose were the primary neutral sugars detected in all species, with 

some arabinose present (data not shown). The amount ofxylan present is critical to some conversion 

processes, and it does vary across species. The major alkali-labile phenolic monomers present 

included p-coumaric acid and ferulic acid. In general, grasses contained approximately 10 times more 

alkali-labile phenolics than legumes. Switchgrass contained over 10 g kg-1 dry weight of the two 

major phenolics. The importance of these phenolics to conversion will depend on the particular 

conversion process. 

Objective 2- Production of Sorghum Doublecropped with Winter Rye 

Winter Annual Rye. Rye was no-till planted in the fall of each year and harvested at a flowering 

stage in the spring prior to sorghum planting. Rye dry matter yields were low and relatively consistent 

across years, except for the drought year of 1988 (Fig. 8). Rye yields were influenced by previous 

nitrogen fertilizer applications to sorghum, with a slight but consistent yield increase with N fertilizer 

applied each year. Rye yields also were affected by location. 

Sweet Sorghum and Sorghum-sudangrass. Sweet sorghum and sorghum-sudangrass were 

planted in conventionally-tilled and no-tilled areas, and herbicides were applied as needed to control 
17 

Cellulose (29.2%) 

Silica 

Figure 4. Switcbgrass composition, 1988. 

Cellulose (23.7%) 

Silica 

Pectin (0.7%) 

Lignin (6.6%) 

Crude Protein (6.3%) 

Nonatructural CHO (5.3%) 

Pectin (0.7%) 

Lignin (5.2%) 

Crude Protein (11.3%) 

Nonstructural CHO (10.9%) 

Other Solubles (14.8%) 

Figure S. Reed canarygrass composition, Harvest Date 2, 1988. 
18 

Pectin (8.7%) 

Hemicellulose Crude Protein (20.9%) 

Nonstructural CHO (2.8%) 

Cellulose (20.3%) 

Other Solubles (29.2%) 

Figure 6. Birdsfoot trefoil composition, Harvest Date 2, 1988. 

Pectin 

Hemicellulose 

Crude Protein (17.3%) 

Cellulose (25.5%) · Nonstructural CHO (4.5%) 

Other Solubles (25.2%) 

Figure 7. Alfalfa composition, Harvest Date 3, 1988. 
5.5 

-I c 5.0 

.r::. 

~4.5 

.. "C 4.0 

Q) 

·->- 3.5 

3.0 

19 

... o 1989 

· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·. ·. ·. ·o-.......... ::. · · · · t986 · · 

•· _,'Y 1987 • • • • • • • • • • • • • • • • • • ' • • I : : 0.. : • • • • • • • • • ·, • • • • '.1/1' • ,"':: • • • • • • • • • • • • • • • • • 

····· 'Y - - -'Y 

- . .......... . ""!' ...........•..•.•......•••..............••••••••••.... - ................................................ :::::=--. !988 .. ••••••• 

•·•·•······· 

0 

............. 

50 100 

-1 

Nitrogen, kg N ha 

150 

Figure 8. Winter annual rye yield response to nitrogen fertilizer carryover from applications to 

sorghum in previons years. 
20 

grasses and broadleafweeds. Sorghum-sudangrass was mature (ripe grain stage) at all sites by the first 

week of September and was harvested at that time. It had accumulated essentially all of its dry matter 

at that time, and was removed before lodging became a problem. Sweet sorghum was harvested at all 

sites during the last week of September to the first week of October, to allow enough time to get rye 

established at the sites. Sweet sorghum was in a flowering to a seed stage at harvest. 

Sweet sorghum yielded approximately 30% more dry matter than sorghum-sudangrass in all 

years except the drought year of 1988 (Table 4 ). Part of this incr~sed yield was d.:ue to the longer 

growing season for sweet sorghum. Sorghum yield was not greatly affected by tillage treatment, 

indicating that the no-till method may be superior from the standpoint of production costs and soil 

erosion. 

Biomass yields of the doublecrop system exceeded 31 Mg dry matter ha·1 at high N fertiHzer 

rates. There was a consistent sorghum yield response to N fertilizer in 1985 and 1986, but was not as 

evident in 1987 and 1988 (Fig. 9). The drought of 1988 resulted in extremely low dry matter yields at 

two of the sites, producing a very low average yield for 1988. The decline in average yield from 1985 

to 1987 (Fig. 9) may be the result of having sorghum in monoculture. 

Objective 3 - Production of Sorghum Interseeded in Perennial Grasses 

Sweet sorghum and sorghum-sudangrass were interseeded into tall fescue and reed 

canarygrass sod at two sites in 1986 and four sites in 1987. Paraquat treatment was effective in 

reducing competition of tall fescue (Table 5), but was not effective with reed canarygrass. Yields of 

sorghum were unacceptably low. Although it was possible to establish sorghum in a reed canarygrass 

stubble, competition from the reed canarygrass prevented the sorghum from developing into a 

significant yield component. 

Interseeding of sorghum into tall fescue was highly dependent on site and environmental 

conditions. The best combination of treatments was sorghum-sudangrass, paraquat treatment, and 

fertilization at 200 kg N ha -

1. This combination does not compare favorably to a management of tall 

fescue alone with 200 kg N ha -

1 fertilization. The second year of interseeding (1987), high N 

fertilization plus paraquat treatment damaged the tall fescue stand at SIPAC. Due to its dependence 

on environmental conditions and the need for a high level of management inputs, interseeding is not 

a viable option for biomass production. 
Table4. 

1985 

1986 

1987 

1988 

1985 

1986 

1987 

1988 

21 

Dry matter yield of sweet sorghum and sorghum-sudangrass as 

influenced by species and tillage. 

Species 

Sorghum-sudangrass Sweet sorghum 

---------- Mg ha -

1 --------

16.4 22.2 

12.6 19.1 

10.6 15.8 

8.3 8.9 

Tillage 

Conventional No-till 

--------- Mg ha -

1 --------

18.0 

16.8 

12.5 

9.0 

14.8 

13.8 

8.2 

Significancea 

** 

** 

** 

** 

Significancea 

** 

** 

** 

a** Significant at P < 0.01. 
Cll 18 . 

~16 

:E 14 

:i 12 

• ·- 10 

> 8 

6 

4 

2. 

0 

1985 

22 

H • 100 • ••• •••• 150 

··--

1986 1987 1988 

Figure 9. Sweet sorghum yield response to nitrogen fertilization (0, 50, 100, and 150 kg N ha-1

) 

averaged over four replicates, four locations, and two tillage treatments. 
TableS. 

T-FLAT 

T-SLOPE 

SEPAC 

SIPAC 

T-FLAT 

T-SLOPE 

SEPAC 

SIPAC 

23 

Dry matter yield of sweet sorghum and sorghum-sudangrass interseeded 

into tall fescue as influenced by herbicide application and sorghum 

species in 1987. 

Herbicide 

No Paraquat Paraquat 

--------- Mg ha-l -------

0.12 0.68 

0.03 

0.20 

0.27 

Species 

0.32 

2.32 

3.31 

Significance8 

•• 

•• 

•• 

•• 

Sorghum-sudangrass Sweet sorghum Significancea 

--------- Mg ha-l --------

0.66 0.14 

0.25 0.10 

1.28 

2.12 

1.24 

1.46 

• 

** 

NS 

NS 

a • ** , Significant at P < 0.05 and P < 0.01, respectively. 
24 

Objective 4- Production Potential of Photoperiod-Sensitive and Insensitive Sorghums 

Two locations (T-FLAT and SIP A C) were selected for this objective, and a range of sorghum 

genotypes was planted in 1988 and 1989. Five commercial hybrid forage sorghums were included with 

the photoperiod-sensitive genotypes in 1989. Both 100 and 200 kg N ha-1 treatments were applied, 

with some differences in yield due to nitrogen fertilizer. Genotypes also were harvested either once 

or twice during the season in 1989. This was done to see if yield could be maintained with two 

harvests, while at the same time reducing the problem of lodging. 

Dry matter yields were high during the drought ofl988, yielding up to 33 Mg dry matter ha-1 in 

replicated trials (data not shown). Hybrid com planted at the same time did not have a significant 

grain yield, and total dry matter yields were 4 to 5 Mg dry matter ha-l. This study was sown in early 

May, which was early enough in the spring to take advantage of soil moisture available, and stands 

were excellent. This is in contrast to sorghum planted in late May, 1988, under Objective 2, which was 

greatly affected by the drought. 

Sorghum-sudangrass was included in this trial in 1988, in order to determine if two harvests per 

year would extend its growing season such that higher yields would result. Two-harvest yields of 

sorghum-sudangrass in 1988 were not different from one-harvest yields in past years, making 

sorghum-sudangrass a less attractive biomass option than sorghum. 

Additional commercial sorghum hybrids were added to the study in 1989 and a total of 11 

sorghum genotypes were studied. Two-harvest yields were significantly lower than one-harvest yields 

in all cases (Table 6). Higher yields were produced at the T-FLATsite, and replicated yields for one 

variety ('Sucro Sorgo 506') reached 39 Mg dry matter ha-1. Genotypes ranged from 0 to 25% of the 

dry weight as grain. Plant heights ranged from 2.2 to 5.5 m. There was a considerable range in plant 

lodging resistance with 'Grassl' the most susceptible to lodging. Sweet sorghum and 'Vartan' 

genotypes also were susceptible to lodging. 

Plant Composition. A considerable range in composition exists in sorghum (Fig. 10-11). 

Neutral detergent fiber content ranged from 543 g kg-1 dry weight in sweet sorghum to 730 g kg·1 dry 

weight in 'Vartan 2319'. This large range in composition coupled with the range in lodging resistance 

indicates that there is considerable potential for improving sorghum's composition and lodging 

resistance. Composition was not greatly influenced by location or nitrogen fertilizer level. 
25 

Table6. Dry matter yield of sorghum as influenced by species and cutting 

management in 1989.a 

One Harvest Two Harvests 

Dekalb-Pfizer 'FS25E 

M-81E sweet sorghum 

Vartan 2319 

Grassl 

Vartan3192 

PAG 'FS-466' 

Purdue Hybrid 

Funks 'G1990' 

Pioneer '931' 

Vartan 3 

NK 'Sucro Sorgo 506' 

BLSDb (one value applies to both columns) 

-------- Mg ha-l ------

25.56 17.43 

27.48 15.61 

21.39 12.80 

25.72 15.52 

25.97 15.44 

23.11 16.28 

15.94 

31.45 15.25 

30.51 19.04 

27.05 

32.95 18.02 

6.1 

a The 'Purdue hybrid' and 'Vanan 3' were harvested once only, due to a shortage of 

seed. 

b Bayes least significant difference (P approximately 0.05). 
26 

Crude Protein {5.1%) 

Cellulose (24.5%) Nonslructural CHO (20.5%) 

Silica 

(18.1%) 

Figure 10. Sweet sorghum ('M81E') stover composition, 1988. 

Cellulose (35.1%) Pectin (1.3%) 

Lignin (7.4%) 

Crude Protein (6.3%) 

Silica (1.5%) Other Solubles (10.7%) 

Nonstructural CHO (7.4%) 

Figure 11. Sorghum ('V2319') stover composition, 1988. 
27 

Objective 5 - Yield and Persistence of Southern U.S. Species 

The high producing southern U.S crops, weeping lovegrass and sericea lespedeza were studied 

for persistence and yield at T-FLAT and SIPAC. Big bluestem, switchgrass, and alfalfa also were 

included for comparison. Stands were established in 1988, with re-establishment of grasses in 1989 

required at SIP A C. 

Switchgrass outyielded the other grasses in 1989 at T-FLAT (Table 7). Lovegrass stands 

survived the winter in excellent condition at T-FLAT, and three harvests were taken in 1989. 

Lovegrass stands at SIP AC did not survive the winter. Indiana is at the northernmost boundary for 

lovegrass survival, and it is questionable whether or not it will persist this far north. Sericea lespedeza 

is adapted to southern Indiana, and outyielded alfalfa at SIPAC (Table 7). When land is suitable for 

alfalfa as at T-FLAT, however, lespedeza will not produce more biomass than alfalfa. 

Objective 6 - Relative Productivity of Switchgrass and Big Bluestem 

Switch grass has consistently produced high dry matter yields, with a minimum of N fertilization. 

Another warm-season perennial grass with high production potential is big bluestem. Five-year-old 

established stands of these two grasses at the Purdue Agronomy Farm were used for this study in 1988 

and 1989. The stands had no treatments imposed on them previously, and were fertilized with 

minimum nitrogen. 

Switch grass was harvested two weeks earlier than big bluestem since it matures earlier. A typical 

pattern of yield with nitrogen fertilizer was observed. Switch grass consistently outyielded big 

bluestem (Table 8), as it did under Objective 5. 
28 

Table7. Dry matter yield of warm-season perennial grasses, alfalfa, and sericea 

lespedeza in 1989. 

Big bluestem 

Switchgrass 

Weeping lovegrass 

Alfalfa 

Sericea lespedeza 

T-FLAT 

9.0a 

15.2 

11.5 

T-FLAT SIPAC 

-------- Mg ha -

1 --------

15.9b 7.9 

8.6 10.2 

a Means of three replicates and three nitrogen rates. 

b Means of three replicates and two locations. Significant species X location 

interaction (P < 0.01). 
TableS. 

1988 

1989 

29 

Dry matter yield of big bluestem and switchgrass at the Purdue 

Agronomy Farm. 

Species 

Big bluestem Switchgrass Significancea 

---------- Mg ha -

1 ---------

6.8 10.0 ** 

9.7 11.7 ** 

a ** Significant at P < 0.01. 
30 

SUMMARY AND CONCLUSIONS 

Soil organic matter was not adversely affected by the selected crop management systems. Soil 

aggregate stability improved at three sites which had previous crops of conventionally-tilled com. 

Perennial sod-forming grasses improved soil stability more than legumes. High nitrogen fertilization 

had a negative effect on aggregate stability, and no-till planting of sorghum improved aggregate 

stability over conventional tillage. 

Of the perennial species investigated._ switchgr~ li.PJ>C!!J]1Q hav~.J.h~ most biom~ ]2Qtenti31 

from an agronomic standpoint. With minimum fenilizer inputs and one harvest per year, it is 

superior in yield to the other perennial species studied._Switchgrass.J!.elded as much as 16 Mg dry 

matter ha-l fi:Q!!l two C!lttings i~_n. Once established, switchgrass is also very persistent, and a 

stand will last indefinitely. ~elds were.Jess affected by drought than other perennial 

grasses. Switchgrass was difficult to establish at some sites, and more research needs to be done to 

ensure quick establishment. Switchgrass breeding to-date has not stressed maximum biomass yield, 

and higher production potential likely exists. 

Sorghum double-cropped with winter annual rye was a very productive management option, with 

yields as high as 31 Mg dry matter ha-l. Sorghum yield was not greatly reduced under a no-till 

management system. Sorghum-sudangrass was a less productive option, whether one or two harvests 

were taken per year. This option requires more inputs than with switchgrass, and erosion potential is 

greater than with switchgrass. Over time, sorghum in monoculture had reduced yields. It would be 

useful to evaluate sorghum in rotation with other crops, such as soybeans, to see if this effect can be 

eliminated. 

Interseeding sorghum into perennial grasses does not appear to be a viable option for biomass 

production, due to its great dependence on environmental conditions and the need for high level 

management inputs. 

PllQtQ.period::S~nsl!jy~JliUtb)'l>~;idJoJ:ag~ ~rgbum~. ~J.e <;;ip!!>le qfpiOducing. .v.ery: lligh yjelds, 

with up to 39 Mg dry matter ha-l produced jn r~licaJ¢...Jr!als,. A two-harvest management resulted 

in no significant lodging of plants, but yields were considerably lower than under one-harvest 

management. A wide range was found in yield, height, grain production, and lodging resistance. 

Since this management option has great biomass potential, an even larger range of germ plasm should 

be evaluated to determine the full potential of this species. 'Grassl' was highest yielding in 1988, but 

• 
31 

only an average producer in 1989. It would be useful to evaluate sorghum over a number of years to 

observe response to varying climatic conditions, and with the experience from monoculture of 

sorghum, in rotation with other species. 

Sericea lespedeza and weeping lovegrass are able to survive the winter in Indiana, but are not as 

well adapted as other species, and will probably not produce yields which are competitive with species 

well adapted to the region. 

Plll_!!t.J;Q~J>~~i!iQ,J!:"'liS greatly affected by species, but n()t by location or manag~ment ······' """•- ·-- --- --- ----- .. 

2reatmen~. Pectin and crude protein content were generally high in legumes, and silica content was 

higher in grasses than legumes. Sorghum exhibited a very large range in composition across 

genotypes, and has good potential to be modified to suit particular conversion processes. Lodging 

resistance in sorghum also is relatively easy to transfer to a particular genotype, making modification 

of sorghum a viable option for the future. 
32 

REFERENCES 

Cherney, J. H., Johnson, K D., Lechtenberg, V. L., and Hertel, J. M. 1986. Biomass Yield, Fiber 

Composition and Persistence of Cool-Season Forage Grasses, Biomass 10:175-86. 

Cherney, J.H., and G. C. Marten. 1982. Small grain crop forage potential: II. Interrelationships 

among biological, chemical, morphological, and anatomical determinants of quality. Crop Sci. 

22:240-245. 

Heath, M. E.., Metcalfe, D. S., and Barnes, R. F. 1985. Forages, the Science of Grassland Agriculture, 

Ames, Iowa: Iowa State Press. 

Marten, G. C., Clapp, C. E., and Larson, W. E. 1980. Effects of Municipal Waste Water Effluent on 

Performance and Feed Quality of Maize vs. Reed canarygrass,J. Environ. Quality 9:137-41. 

Office of Technology Assessment, U.S. Congress. 1980. Energy from Biological Processes, U.S. Govt. 

Printing Office. 0-65-498. Washington, D.C. 

Other Publications 

Greene, D.K, KD. Johnson, J.H. Cherney, and J.J. Volenec. 1987. Biomass yield and chemical 

composition of sorghum and rye doublecropped on marginal land. Agron. Abst. p. 112. 

Cherney, J.H., J. Lowenberg-DeBoer, KD. Johnson, and JJ. Volenec. 1989. Evaluation of grasses 

and legumes as energy resources. Proc. Energy from Biomass and Wastes XII. Feb. 15-19, 1988, 

New Orleans, LA Institute of Gas Technology, Chicago, pp. 289-323. 

Lowenberg-DeBoer, J., and M.A Lopez-Pereira. 1988. Risk assessment for herbaceous biomass 

crops: The case of perennial grasses. Southern Biomass Conference. July 26-28, 1988, Auburn 

University. 

Greene, D.K, KD. Johnson, J.H. Cherney, and J.J. Volenec. 1988. Biomass yield and chemical 

composition of perennial grasses grown on marginal lands. Agron. Abst. p. 127. 

Cherney, J.H., KD. Johnson, J.J. Volenec, and KS. Anliker. 1989. Chemical composition of 

herbaceous grass and legume species grown for maximum biomass production. Biomass 17:215-

238. 

Lowenberg-DeBoer, J., and J.H. Cherney. 1989. Biophysical simulation for evaluating new crops: 

The case of switchgrass for biomass energy feedstock. Agric. Systems 29:233-246. 

Greene, D.K, KD. Johnson, J.H. Cherney, and JJ. Volenec. 1989. Feasibility of interseeding 

sorghum into cool-season grass sod.Agron. Abst. p. 132. 

Greene, D.K, KD. Johnson, J.H. Cherney, and J.J Volenec. 1990. Biomass yield and chemical 

composition of doublecropped sorghum and rye. In Proc. Forage and Grassland Con[., 6-9 June, 

1990, Blacksburg, VA, pp. 324-328. 
• 

.. 

.. 

1. 

2-11. 

12-21. 

22. 

23. 

24-33. 

34. 

57. 

58. 

59. 

60. 

61. 

62. 

63. 

64-73. 

74. 

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J. W. Johnston 

J. W. Ranney 

G. A Tuskan 

A F. Turhollow 

R. I. Van Hook 

33 

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INTERNAL DIS1RIBUTION 

35. 

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52-53. 

54. 

55. 

56. 

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Central Research Library 

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Laboratory Records, RC 

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ORNL Y-12 Technical Library 

EX1ERNAL DIS1RIBUTION 

C. S. Accola, 1496 Agronomy Hall, Iowa State University, Ames, lA 50011 

I. C. Anderson, Dept. of Agronomy, Iowa State University, Ames, lA 50011 

P. C. Badger, Southeastern Regional Biomass Energy Program, National Fertilizer 

and Environmental Research Center, Tennessee Valley Authority, CEB IS 742-M, 

Muscle Shoals, AL 35660-1010 

J. Berning, Electric Power Research Institute, 3412 Hillview Ave., P. 0. Box 10412, 

Palo Alto, CA 94303 

D. Bransby, Dept. of Agronomy and Soils, Auburn University, Auburn University, 

AL 36849 

J. L. Butler, Coastal Plain Experiment Station, Agricultural Research Service, P. 0. 

Box 748, Tifton, GA 31793 

D. R. Buxton, Dept. of Agronomy, Iowa State University, Ames, lA 50011 

J. H. Cherney, Department of Agronomy, Purdue University, West Lafayette, IN 

47907 

M. Collins, University of Kentucky, N-122 Agricultural Sciences Bldg.-N, Lexington, 

KY 40546-0091 

J. S. Cundiff, Department of Agricultural Engineering, Virginia Tech, Blacksburg, 

VA 24061 

W. Lee Daniels, Department of Agronomy, Virginia Tech, Blacksburg, VA 24061 

C. L Dobbins, Dept. of Agricultural Economics, Purdue University, W. Lafayette, IN 

47907 

B. C. English, Dept. of Agricultural Economics and Rural Sociology, P. 0. Box 1071, 

University of Tennessee, Knoxville, TN 37901-1071 

D. 0. Erickson, Animal and Range Science Dept., North Dakota State University, 

Fargo, ND 58105 

J. E. Ferrell, Biofuels Systems Division, Department of Energy, MS CE-341, 

Forrestal Building, 1000 Independence Avenue, S.W., Washington, DC 20585 

G. W. Fick, Department of Agronomy, Cornell University, Ithaca, NY 14853 

G. Grinnell, Office of Energy, U.S. Dept. of Agriculture, Administration Building, 

Route 194E, 14th and Independence Ave., Washington, DC 20250..2600 

D. K. Green, Dept. of Agronomy, Purdue University, W. Lafayette, IN 47907 

T. L. Grove, Department of Agronomy, Cornell University, Ithaca, NY 14853 

K. D. Johnson, Dept. of Agronomy, Purdue University, W. Lafayette, IN 47907 

E. J. Kladiuko, Dept. of Agronomy, purdue University, W. Lafayete, IN 47907 

F. J. Kuzel, Council of Great Lakes Governors, 310 S. Michigan Ave., lOth Floor, 

Chicago, IL 60604 

D. J. Lathwell, Department of Agronomy, Cornell University, Ithaca, NY 14853 
98. 

99. 

100. 

101. 

102. 

103. 

104. 

105. 

106. 

107. 

108. 

109. 

110-119. 

120. 

121. 

122. 

123. 

124-133. 

34 

J. Lowenberg-DeBoer, Dept. of Agricultural Economics, Purdue University, W. 

Lafayette, IN 47907 

A Mdafri, Dept. of Agricultural Economics, Purdue University, W. Lafayette, IN 

47907 

D. W. Meyer, Agronomy Department, North Dakota State University, SU Station, 

Fargo, ND 58105 

D. J. Parrish, Department of Agronomy, Virginia Tech, Blacksburg, VA 24061 

P. V. Preckel, Dept. of Agricultural Economics, Purdue University, W. Lafayette, IN 

47907 

M. W. Phillips, Dept. of Agronomy, Purdue University, W. Lafayette, IN 47907 

N. Rader, Public Citizen, 215 Pennsylvania Ave, S.E., Washington, D.C. 20003 

D. Rhinebolt, NWEA, 1730 N. Lynn St., Suite 610, Arlington, VA 22209 

J. C. Roetheli, USDNSPPS, 14th and Independence Ave., S.W., Suite 342, 

Aerospace Bldg., Wshington, DC 20251-2200 

D. Stucky, Dept. of Agricultural Economics, Purdue University, W. Lafayette, IN 

47907 

W. Tyner, Dept. of Agricultural Economics, Purdue University, W. Lafayette, IN 

47907 

D. H. Vaughan, Department of Agricultural Engineering, Virginia Tech, Blacksburg, 

VA 24061 

J. J. Volonec, Dept. of Agronomy, Purdue University, W. Lafayette, IN 47907 

W. Tolles, Applied Science Associates, Lee Highway, Fairfield, VA 24435 

D. D. Wolf, Department of Agronomy, Virginia Tech, Blacksburg, VA 24061 

N. A Wright, Geophyta, Inc., 2685 C. R. 254, Vickery, OH 43464 

Office of Assistant Manager for Energy Research and Development, Oak Ridge 

Operations, P.O. Box 2001, Department of Energy, Oak Ridge, TN 37831-8600 

Office of Scientific and Technical Information, P.O. Box 62, Oak Ridge, TN 37831 

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