# Presentation: 447266

## Switchgrass as a Biofuel in the Chariton Valley, Iowa Agronomic Considerations 

**Lee Burras, Charlie Brummer, Marty Braster,  John Sellers, & Mike Barker**
**Iowa State University & Chariton Valley RC&D**
**ORNL BFDP  Cooperators Meeting, Memphis**
**November 07, 2001**

## Outline

**Objectives**
**Site overview**
**Review of project  = significant conclusions**
**How ready are we to produce switchgrass?**
**Summary**
**As questions come up, please ask**.

## General Research Objectives

_**1997 onward**_
**Identify/develop SWG cultivars suitable for biofuels and adapted to south-central Iowa.**
**Examine SWG yield at the field level.**
**Examine SWG impact on soil quality.**
**	**Part of a scale-up project that includes upgrading the Ottumwa Generating Station and burning of 4000 tons of SWG.  See _[http://www.cvrcd.org](http://www.cvrcd.org/)__. _
_**2000 onward**_
**Do the same for reed canary grass (RCG)**

## Who does and has done the real work for ISU?

***Mike Barker – Research Associate, ISU***
***Julie McLaughlin – Research Associate, ISU***
***Rocky Lemus – PhD student, VA Tech***
***Neil Molstad – SDI Consulting, Oak Brook, IL***

## Overview of site  soils & weather

## Landscape Characteristics of the Chariton Valley

**Landscape Characteristics of the Chariton Valley**

## Relative agronomic productivity across Iowa ( CSR values given)

## Objective 1: Identify SWG cultivars suitable for biofuels and adapted to SC Iowa.

**Ongoing evaluation of 20 SWG cultivars planted in 1997.**
**Plot study – randomized complete blocks  w/ 8 replications.**
**Plot size = 3.0 * 4.6 m**
**Spring N @ 78 kg ha****-1****.**
**Biomass yield (fall harvest).**
**Laboratory: fiber, total N,  Ash, Cl, P, & S, etc. **

## Results - SWG cultivars suitable for biofuels and adapted to SC Iowa (small plots).

**Yields highly variable.**
**Yields improved from 1998 to 1999 (6.4 Mg ha****-1**** and 11.8 Mg ha****-1****, respectively).**
**No 2000 yields b/c wet fall then snow.**
**Highest = lowland varieties**** ****(Alamo = 17 Mg ha****-1****; Kanlow = 16 Mg ha****-1****) – some uplands 15 .**
**Higher yields seem possible and likely.**
_**Caution**_**: cold, snowless winter impact on lowland varieties?**

## Results - SWG cultivars suitable for biofuels and adapted to SC Iowa (small plots).

**Varieties average comparable ADF (47%), ADL (6%) and ash contents (5%), respectively.**
**Varieties differ in height (150-220 cm), NDF (80%), N (0.4-0.6%) and IVDMD (23-30%)**

## Results - SWG cultivars suitable for biofuels and adapted to SC Iowa (small plots).

**Chemical compositions all ok for co-firing.**
**Reduction in Cl, P, and S occur between November & March.**
**Lodging & disease ******** all varieties.**
**Spring harvest?**
**Co-selecting for yield and biofuel quality seems reasonable.**

## Objective 2: SWG yields at the field level.

**Two approaches**
**	****--- four “ISU” managed fields (N fertility & landscape positions), yields from 1998, 1999, 2000.**
**	****--- Farmer fields - farmer harvests., ****	**
**	****data from 45 strips & 12 fields, just 1999 data currently.  All strips 112 kg N and atrazine weed control.**

## ISU field set up

- 0

- 224

- 112

- 56

## Results: SWG yields in four ISU managed fields.

**theses for Rocky Lemus & Neil Molstad, now Mike Barker.  **
**Mean yields of 3, 4, and 6 Mg ha****-1**** for 1998, 1999, & 2000, respectively.**
**Appropriate N is 60 to 100 kg ha****-1**** yr****-1****. **
**Summits highest yielding.**
**Cell wall characteristics do not vary much by year, location, or fertility.**
**Overwintering SWG in the field improves biofuel characteristics but at big yield loss.**

## Farmer yields

- Average was 6.5 Mg ha-1 w/ range being 3 to 16 Mg ha-1.
- Yield is proportional to CSR.  Best soils are loess-derived (summits); poorest soils are paleosols (backslopes).

## Objective 3: SWG & soil quality

**Objective 3: SWG & soil quality**

**OC ranges from 5 to 34 kg m-3:  Pastures>SWG>Row Crop.**
**Upland OC ratios are 0.5-0.8-1.0 for 20cm-50cm-100cm, respectively.**
**Least OC is on BS (where most erosion & lowest yields are).**
**Gullies – common big problem**
**SWG promotes stable aggregates & thickening of A horizon.**

## So, how ready are we to really grow SWG?

## How ready are we to produce switchgrass?

- We can produce switchgrass in an environmentally benign fashion.
- But we need to manage for all types of water erosion.  Backslopes are the problem.  And we need more knowledge on nitrates and off farm impacts.
- We can produce switchgrass having meaningful agronomic yields (6 Mg ha-1). In fact, my guess is we could double or triple yields on better ground.
- But this may negate beneficial impacts desired for fragile lands in the area.  It may also shift production to the higher CSR ground away from Ottumwa.
- We can produce switchgrass in a manner beneficial to the rural economy of Iowa.

## How much time do we need?

- It depends.  How much SWG do we want?  We are producing a few thousand tons per year now.
- If we want a lot more we need two to three years lead time

## Questions & Comments?