**GENETIC VARIATION AMONG SWITCHGRASSES FOR AGRONOMIC TRAITS, FORAGE
QUALITY, AND BIOMASS FUEL PRODUCTION**

**K.P. Vogel**

**Research Geneticist**

**USDA-ARS, Lincoln, NE**

**Cooperating Scientists**

+-----------------------------------+-----------------------------------+
| ***Univ. of Nebraska***           | ***USDA-ARS-Mandan, ND***         |
|                                   |                                   |
| **Lowell Moser, Forage Agronomist | **Jon Hanson, Rangeland           |
| and Physiologist**                | Scientist**                       |
|                                   |                                   |
| **Richard Perrin, Agricultural    | **John Berdahl, Plant Breeder -   |
| Economist**                       | Forages**                         |
|                                   |                                   |
| ***USDA-ARS-Lincoln***            | **Albert Frank, Plant             |
|                                   | Physiologist**                    |
| **Gary Varvel, Soil Scientist**   |                                   |
|                                   | **Joseph Krupinsky, Plant         |
| **Vacant, Forage                  | Pathologist**                     |
| Agronomist/Rangeland Scientist**  |                                   |
|                                   | **Mark Liebig, Soil Scientist**   |
|                                   |                                   |
|                                   | **Holly Johnson, Rangeland        |
|                                   | Scientist**                       |
+-----------------------------------+-----------------------------------+
| ***South Dakota State             | ***USDA-NRCS***                   |
| University***                     |                                   |
|                                   | **John Kimble, Soil Scientist**   |
| **Kevin Kephart, Dean of          |                                   |
| Experiment Station, Forage        | **Susan Samson-Liebig, Soil       |
| Agronomist**                      | Scientist**                       |
|                                   |                                   |
| **Arvid Boe, Plant Breeder -      |                                   |
| Forages**                         |                                   |
|                                   |                                   |
| **James Doolittle, Soil           |                                   |
| Scientist**                       |                                   |
|                                   |                                   |
| **Thomas Schumacker, Soil         |                                   |
| Scientist**                       |                                   |
|                                   |                                   |
| **Douglas Malo, Soil Scientist**  |                                   |
|                                   |                                   |
| **Jin-Ho Lee, Soil Scientist**    |                                   |
|                                   |                                   |
| **Kenneth Higgins, Wildlife       |                                   |
| Biologist**                       |                                   |
|                                   |                                   |
| **Vance Owens, Forage             |                                   |
| Agronomist**                      |                                   |
+-----------------------------------+-----------------------------------+
| ***University of Wisconsin***     | ***USDA-ARS- Fort Collins, CO.*** |
|                                   |                                   |
| **Michael Casler, Plant Breeder-  | **Ronald Follett, Soil            |
| Forages**                         | Scientist**                       |
+-----------------------------------+-----------------------------------+

**[1997-2001 Objectives:]{.underline}**

**(1) Continue studies to determine the feasibility of producing F1
switchgrass hybrid cultivars and quantify the extent of heterosis for
biomass yield;**

**(2) Continue the development of switchgrass cultivars for USDA Plant
Hardiness Zones 2,3, 4, and 5 using conventional grass breeding methods
and evaluate improved strains in regional trials;**

**(3) Continue molecular genetic studies on classifying switchgrass
germplasm and developing molecular genetic markers;**

**(4) Evaluate, develop, and test switchgrass cultivars for Northern
Midwest and Great Lakes States (Hardiness zones 2,3, & upper 4) in
cooperation with Dr. Michael Casler at the University of Wisconsin.**

**[In 1999, project expanded at the request of the Oak Ridge National
Laboratory:]{.underline}**

**(5) Development of a white paper on the assessment of the potential
for genetic modification of herbaceous plants for fuel feedstock;**

**(6) Establish switchgrass field trials in North Dakota in cooperation
with the USDA-ARS Northern Plains Research Laboratory, Mandan, ND
(ARS-Mandan) to assess the biomass yield of switchgrass cultivars in
North Dakota;**

**(7) Establish switchgrass field trials in South Dakota in Cooperation
with South Dakota State University (SDSU) via a Specific cooperative
Agreement to assess the biomass yield of switchgrass cultivars in South
Dakota.**

**In 2000 at the request of DOE, additional objectives were added:**

**(8) Determine the biomass yields of switchgrass grown on commercial
scale production fields in potential production regions of Nebraska,
South Dakota, and North Dakota. Determine the economic costs associated
with switchgrass biomass production using commercial scale farm
equipment by participating farmers. Research managed and coordinated by
ARS-NE and the Univ. of Nebraska.**

**(9) Determine and quantify the environmental benefits associated with
switchgrass biomass production in the upper plains including changes in
soil carbon levels and other changes in soil quality.**

> **(A) Compare carbon sequestration and yields of switchgrass grown for
> biomass compared with no-till corn at varying productivity levels
> induced by N fertility treatments. ARS-NE, ARS-CO, NRCS.**
>
> **(B) Evaluate carbon sequestration in switchgrass fields in on-farm
> trials and adjacent crop land. ARS-NE, ARS-Mandan, NRCS.**
>
> **(C) Evaluate the efficiency and extent of soil carbon storage in
> selected switchgrass stands throughout ND, SD, and MN; in doing so,
> determine the potential effects of switchgrass on soil quality.
> ARS-Mandan.**

**(10.) Evaluate the yield potential and production economics of
managing former CRP grasslands as a biomass cropping system. Determine
the best agronomic practices for converting and managing former CRP for
use in biomass production. Determine effects of management practices
including harvesting schemes on wildlife habitat quality. Determine
effect of management of former CRP as a biomass crop on soil quality
including changes in soil carbon. Research managed and coordinated by
South Dakota State University (SDSU).**

**(11.) Develop new technologies and plant germplasm to address specific
production problems including:**

> **(A) Develop methods for quantifying switchgrass seed quality in
> terms of its capability to produce established plants under field
> conditions. Cooperative research, R. Masters & L. Moser, ARS-NE and
> Univ. of Nebraska.**
>
> **(B) Identify, evaluate, and obtain agronomic information that will
> lead to the registration of herbicides for controlling weeds in
> switchgrass during establishment. R. Masters, ARS-NE.**
>
> **(C) Determine the mineral nutrient requirements of switchgrass in
> the upper Great Plains. ARS-Mandan.**
>
> **(D) Determine if cultivars need to be developed for the more arid
> sections of the Northern Plains region and determine genetic variation
> in elite breeding lines for biomass production in semi-arid
> environments. Arvid Boe, SDSU.**
>
> **(E) Monitor and identify disease problems associated with growing
> switchgrass as a biomass fuel crop and seed production of switchgrass.
> Joe Krupinsky, ARS-Mandan**

**1997- 2001 Accomplishment by Objectives.**

**(1) Continue studies to determine the feasibility of producing F1
switchgrass hybrid cultivars and quantify the extent of heterosis for
biomass yield;**

**a. Basic genetic study completed that demonstrated that switchgrass
has a prefertilization incompatibility system that is similar to the S-Z
system that exists in other grasses. Two post fertilization
incompatibility systems exist, one among ploidy levels that restrictions
the production of viable seed from between ploidy level crosses.
Manuscript completed , will be submitted to Crop Science in Nov.**

**b. Field evaluation of two sets of hybrids was completed. Results
indicate that heterosis for biomass yields exists by progeny of some
populations and plants from those populations. Upland and lowland
ecotypes as represented by Summer and Kanlow represent distinct
heterotic groups. Manuscript in preparation.**

**c. A seed production study was completed to determine if acceptable
yields of switchgrass seed could be obtained from space-transplanted
seed production fields as compared to row and solid stands. Results were
positive. Manuscript in preparation.**

**Research will continue in new project.**

**(2) Continue the development of switchgrass cultivars for USDA Plant
Hardiness Zones 2,3, 4, and 5 using conventional grass breeding methods
and evaluate improved strains in regional trials;**

**a. Research continued with several populations. New selection criteria
developed. Seedling tiller number at six weeks. A.S. Smart Ph.D
Dissertation.**

**Table 2.3. Mean tiller number and shoot weight averaged over two
experiments of populations developed by two cycles of divergent
selection for seedling tiller number while selecting for high shoot
weight in switchgrass seedlings 6 to 8 wk after planting.**

  ---------------- ---------------------- ------------------- ---------------
  **Population**   **Cycle**              **Mean tiller       **Shoot weight
                                          number**            g plant^-1^**

  **Base**         **0**                  **1.62**            **0.39**

  **SWMT**         **1**                  **2.05**            **0.39**

  **SWMT**         **2**                  **2.01**            **0.41**

  **SWST**         **1**                  **1.41**            **0.45**

  **SWST**         **2**                  **1.23**            **0.52**
  ---------------- ---------------------- ------------------- ---------------

**Table 4.1. August plant height (H), leaf width (W), leaf length (L),
and number of tillers per plant (T) averaged over two experiments,
measured on big bluestem and switchgrass mature plants developed by
divergent selection for seedling tiller number while selecting for high
shoot weight.**

  ----------------- --------------- --------- ---------- ---------- ----------
  **Species**       **Type ^†^**    **H cm.** **W mm**   **L mm**   **T**

  **Switchgrass**   **SWMT-C2**     **84**    **8.9**    **33**     **119**

                    **SWST-C2**     **92**    **11.4**   **38**     **80**
  ----------------- --------------- --------- ---------- ---------- ----------

**Table 4.3. Number of tillers per plant (T), yield per plant (YPP), and
yield per tiller (YPT) measured with a single end-of-season harvest on
10 October 2000 from second production year of big bluestem and
switchgrass space-planted transplants developed by divergent selection
for seedling tiller number while selecting for high shoot weight in
Lincoln, NE.**

  ----------------- ---------------- ------------ ------------- ------------
  **Species**       **Type^†^**      **T**        **YPP**       **YPT**

  **Switchgrass**   **SWMT-C2**      **301**      **853 g**     **2.8 g**

                    **SWST-C2**      **201**      **1029 g**    **5.1 g**
  ----------------- ---------------- ------------ ------------- ------------

**3. Molecular Genetics Studies.**

**a. Determined that chloroplast DNA in switchgrass is maternally
inherited. Demonstrated that normal chromosome pairing occurs in
upland/lowland tetraploid hybrids indicating that they have the same
genome.**

> **Martinez-Reyna, J.M., K.P. Vogel\*, Carol Caha, and Donald J. Lee.
> 2001. Meiotic stability, chloroplast DNA polymorphisms, and
> morphological traits of upland x lowland switchgrass reciprocal
> hybrids. Crop Sci. 41:1579-1583.**

**b. Parent clones and progenies of Summer x Kanlow hybrids were sent to
Oak Ridge and Univ. of Georgia for use in marker research.**

**In future, emphasis will be on devloping populations that differ for
specific traits to be used in marker studies.**

**4. Breeding switchgrass for the Upper Midwest and Lake States.**

**Research conducted by Dr. Michael Casler, Univ. of Wisconsin.**

**Research reported by Dr. Casler.**

**Objectives Added in 1999.**

**Objective 5. White paper.**

**a. "White paper" entitled "Genetic Improvement of Switchgrass and
Other Herbaceous Plants for use as Biomass Fuel Feedstock" was prepared
by K. P. Vogel and H. G. Jung, USDA-ARS, and delivered to the Oak Ridge
National Laboratory on 15 February, 2000.**

**Paper expanded and published as:**

> **Vogel, K.P. and H.G. Jung. 2001. Genetic modification of herbaceous
> plants for feed and fuel. Critical Reviews in Plant Sciences.
> 20:15-49.**

**Objective 6. Evaluate switchgrass field trials in North Dakota to
assess the biomass yield of switchgrass cultivars in North Dakota**

**a. Research conducted and reported by ARS- Mandan.**

**Objective 7. Evaluate switchgrass cultivars in field trials in South
Dakota.**

**a. Research conducted and reported by South Dakota State University
(SDSU).**

**Additional Objectives Added in FY 2000.**

**Objective 8. Determine the biomass yields of switchgrass grown on
commercial scale production fields in potential production regions of
Nebraska, South Dakota, and North Dakota.**

**Determine the economic costs associated with switchgrass biomass
production using commercial scale farm equipment by participating
farmers.**

**USDA-ARS Lincoln provides technical support for the project and Dr.
Richard Perrin, University of Nebraska Agricultural Economist conducts
economic analysis on the project and manage farmer contracts via a
Specific Cooperative Agreement between the University of Nebraska and
USDA-ARS.**

**In 2000, Contracts established with 4 farmers in Nebraska. Fields
planted. Due to a severe drought, establishment problems developed,
however, only one field had to be replanted in 2001.**

**In 2001, Contracts established with 4 farmers in South Dakota and
three farms in North Dakota. Fields were planted. Stand failure occurred
on one farm.**

**Biomass yields were harvested on three of the Nebraska Farms in 2001.
Yield and economic data were collected.**

**[Objective 9]{.underline}. Determine and quantify the environmental
benefits associated with switchgrass biomass production in the upper
plains including changes in soil carbon levels and other changes in soil
quality.**

**[Objective 9A]{.underline}. A multi-purpose study. Objectives are:**

> **Determine soil C fixation with switchgrass biomass production in
> comparison to no-till corn;**
>
> **Compare production economics of ethanol production for corn vs
> switchgrass biomass with field scale plots;**
>
> **Determine the extent of N and soil mineral utilization in
> switchgrass grown as a biomass crop during a ten year period. Biomass
> and corn yields will be harvested for 10 years.**
>
> **Cooperating scientists are K. Vogel USDA-ARS Lincoln - biomass
> production; Gary Varvel, USDA-ARS Lincoln - corn production; Ron
> Follett, USDA-ARS Ft. Collins, John Kimble and Susan Samson-Leibig,
> USDA-NRCS-NSSC, Lincoln, NE.**

**Map, Tables 20 & 21.**

**[Objective 9B.]{.underline} Evaluate carbon sequestration in
switchgrass fields in on-farm trials and adjacent crop land. ARS-NE,
ARS-Mandan and NRCS.**

**The switchgrass biomass production fields in the on-farm trials in
Nebraska, South Dakota, and North Dakota are being used to obtain field
scale estimates of carbon sequestration.**

**Baseline soil samples were collected on all fields either prior to
planting or within six weeks of switchgrass emergence.**

**Soils will be sampled at the end of the five year period.**

**[Objective 9C.]{.underline} Evaluate the efficiency and extent of soil
carbon storage in selected switchgrass stands throughout ND, SD, and MN;
in doing so, determine the potential effects of switchgrass on soil
quality. ARS-Mandan conducting research. Report by ARS Mandan.**

**[Objective 10.]{.underline} Evaluate the yield potential and
production economics of managing former CRP grasslands as a biomass
cropping system. Research managed, coordinated, and reported by South
Dakota State University (SDSU).**

> **Determine the best agronomic practices for converting and managing
> former CRP for use in biomass production.**
>
> **Determine effects of management practices including harvesting
> schemes on wildlife habitat quality.**
>
> **Determine effect of management of former CRP as a biomass crop on
> soil quality including changes in soil carbon.**

**[Objective 11.]{.underline} Develop new technologies and plant
germplasm to address specific production problems including:**

**[Objective 11A.]{.underline} Develop methods for quantifying
switchgrass seed quality in terms of its capability to produce
established plants under field conditions. Cooperative research, ARS-NE
and Univ. of Nebraska.**

> **Several tests were evaluated on seed lots of three cultivars
> differing in seed size and conventional germination percentages
> including:**

**Germination Rate Index,**

**Emergence from a graded series of planting depths in sand and;**

**Accelerated aging 45 or 50^o^ C at high humidity.**

**Two tests appear to have promising on assessing seed quality. They
are:**

> **1. Emergence from 1.5 to 2 in planting depth in sand and emergence
> in sand,**

**2. Acclerated aging at 50^o^ C for 12 to 24 hrs.**

> **Additional laboratory work will be conducted to refine the tests
> followed by field evaluation trials.**

**[Objective 11B]{.underline}. Identify, evaluate, and obtain agronomic
information that will lead to the registration of herbicides for
controlling weeds in switchgrass during establishment.**

**Based on research conducted previously, the herbicide Plateau is
registered for use on planting warm-season grasses and legumes for CRP
type plantings. It is "hot" on Panicums and should be used on
switchgrass only when stand loses can be tolerated.**

**In 2000, a series of experiments were established to evaluate the
herbicide "Paramount" for establishment of switchgrass. Stands were
evaluated in late spring of 2001 and biomass yields were harvested in
late August or early September. Data are in the process of being
summarized.**

**Data will indicate that Paramount is a very effective herbicide to use
for establishing switchgrass particularily when tank mixed with a broad
leaf herbicide such as atrazine.**

**BASF supplied Paramount for use on on-farm trials in NE, SD, and ND.
Farmers who used Paramount had excellent weed control the establishmeny
year and had yields of 2 to 3 tons dry matter per acre. Farmers who did
not use it had weed problems and had reduced yields and did not harvest
stands.**

**Paramount = quinclorac. Cleared for use in KS, NE, SD, ND, MT, WY, CO,
UT, ID, WA, OR for sorghum and wheat and it currently has a supplemental
label for use on non-cropland acres.**

**It is effective in controlling barnyard grass, green, yellow, and
giant foxtail, and crabgrass. Also controls some broadleaf weeds.
Primarily used for control of grassy weeds. Rate is 8 oz./acre.**

**Cotton is highly susceptible to Paramount and it will likely not be
marketed in states with significant acres of cotton. Other sensitive
species are Solanaceae, Umbelliferae, Leguminoseae (alfalfa, green bean)
Chenopodiceae, Compositeae**

**[Objective 11C]{.underline}. Determine the mineral nutrient
requirements of switchgrass in the upper Great Plains. ARS-Mandan**

**[Objective 11D.]{.underline} Determine if cultivars need to be
developed for the more arid sections of the Northern Plains region and
determine genetic variation in elite breeding lines for biomass
production in semi-arid environments (SDSU).**

**[Objective 11E]{.underline}. Monitor and identify disease problems
associated with growing switchgrass as a biomass fuel crop and seed
production of switchgrass. Joe Krupinsky, ARS-Mandan.**

**[Additional New Information on Switchgrass:]{.underline}**

**Switchgrass toxin: Disogenin**

**Research completed by USDA-ARS Poisonous Plants Research Laboratory at
Logan, Utah demonstrates that switchgrass biomass contains the steroidal
saponins that have been implicated in the poisoning of she ep and
horses.**

**After hydrolsis of the saponins, diosgenin was determined to be the
major sapogenin in switchgrass.**

**In Kleingrass (Panicum coloradum), the major sapogenin is yamogenin.**

**Both compounds affect liver function.**

**Switchgrass and Kleingrass forage are not believed to affect beef
cattle.**

**Thirteen large round bales of switchgrass were trucked to the USDA
PPRL for feeding trials.**

**In 2002, we will sample switchgrass throughout the growing season and
send samples to the PPRL to determine concentration levels during the
growing season and by plant part.**

**Lee, Stephen T.; Bryan L.Stegelmeier, Dale R. Gardner, and Kenneth P.
Vogel. 2001. The isolation and identification of steroidal sapogenins in
switchgrass. J. Natural Toxins 10:273-281.**

**[Proposed New Project 2001-2006.]{.underline}**

**[Objective 1.]{.underline} Develop improved cultivars of switchgrass
for use in biomass energy production fields in the Northern Great Plains
and the Midwest. ARS-Lincoln, Univ. of Wisconsin-Madison, South Dakota
State University, ARS-Mandan.**

> **A. Continue research on developing basic breeding and genetics
> information to development F1 hybrids of switchgrass. ARS-Lincoln.**
>
> **B. Develop switchgrass cultivars with improved biomass yields for
> use in the Central Great Plains and Midwest states at the same
> latitude. ARS-Lincoln**
>
> **C. Develop switchgrass cultivars for use in the Northern latitudes
> of the Great Plains and Midwest states. University of
> Wisconsin-Madison.**
>
> **D. Determine if there are significant genotype x environment
> interaction effects for switchgrass biomass yields between the humid
> and more arid regions of the Northern Great Plains. South Dakota State
> University.**
>
> **E. Determine adaptation and productiviy of experimental strains and
> check cultivars of switchgrass when managed for biomass production in
> the Great Plains and the Midwest. ARS-Lincoln, ARS-Mandan, Univ. of
> Wisconsin-Madison, South Dakota State University.**

**Objective 2. Develop management practices for rapidly converting CRP
grasslands into biomass energy production fields in the Northern Great
Plains and quantify biomass yields and associated environment effects.
South Dakota State University.**

**Objective 3. Determine the field scale yields of switchgrass grown as
a dedicated biomass energy crop in the Northern Great Plains, quantify
the economic costs of production, and monitor associated environmental
effects. ARS-Lincoln, University of Nebraska-Lincoln, and ARS-Mandan.**

**Objective 4. Quantify environmental effects of switchgrass grown as a
biomass energy crop in the Northern Great Plains including carbon
sequestration.**

> **A. Determine carbon sequestration of switchgrass grown for biomass
> in comparative study with no-till corn at varying productivity levels
> induced by N fertility treatments. ARS-NE, ARS-CO, NRCS.**

# B. Determine effect of managing former CRP grasslands for biomass energy crop production on soil quality including changes in soil carbon concentration. SDSU.

> **C. Evaluate carbon sequestration in switchgrass fields in on-farm
> trials and adjacent crop land. ARS-NE, ARS-Mandan, NRCS.**
>
> **D. Evaluate soil carbon storage in old switchgrass stands throughout
> ND, SD, and MN and adjacent cropland to determine the potential
> effects of switchgrass managed as a biomass crop on soil carbon.
> ARS-Mandan.**
>
> **E. Develop a carbon budget for switchgrass in the Northern Great
> Plains to evaluate the relationship between biomass production and
> carbon storage of switchgrass. ARS-Mandan.**
>
> **F. Determine effects of management practices on converting CRP
> grasslands and cropland into perennial biomass crop production fields
> on wildlife habitat quality. SDSU.**

**Objective 5. Develop improved management methods and strategies to
enhance establishment success, determine mineral nutrient requirements
of switchgrass for biomass production, and identify pathogens that can
limit productivity of switchgrass.**

> **A. Develop methods for quantifying switchgrass seed quality in terms
> of its capability to produce established plants under field
> conditions. ARS-NE and Univ. of Nebraska.**
>
> **B. Determine the mineral nutrient requirements of switchgrass in the
> upper Great Plains. ARS-Mandan.**
>
> **C. Monitor and identify disease problems associated with growing
> switchgrass as a biomass fuel crop and seed production of switchgrass.
> ARS-Mandan**