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1 ton/acre (T/A) = 2.24 Mg/ha = 2400 kg/ha

1 Mg/ha = 1000 kg/ha = 0.45 tons/acre

1 g/m² = 10 kg/ha

1 g/kg = 0.1%

1 mg/kg = 1 ppm (part per million)

Biofuel production in the Chariton Valley in southern Iowa would have desirable environmental effects by converting land usually planted to annual row crops into perennial grass cover. Switchgrass, designated by DOE research as the most viable herbaceous biofuel crop, is native to Iowa and has been grown to a limited extent as a forage crop. Its productivity as a biofuel needs to be assessed; the characteristics of a desirable biofuel crop differ from those of a forage, and agronomic practices will likely need to be altered. Additionally, biofuel crops are targeted to the more erodible land in the region, land that varies considerably in soil characteristics, and hence, productive capacity. Reed canarygrass could complement switchgrass, particularly in wet areas, and its ability to form a dense sod may improve erosion control in some instances.

Economic and agronomic analyses of biofuel crops–primarily switchgrass, secondarily reed canarygrass–are needed to determine the feasibility of growing these crops in southern Iowa. In this report, we discuss preliminary research bearing on these issues.

The economic analysis of switchgrass production shows that yield and price are the determining factors for profitability. With moderate yields (3 tons/acre) and price ($50 per ton), switchgrass could produce a significant positive impact for the regional economy. Changing from a corn/soybean rotation to switchgrass will not make a substantial change in energy usage to produce the crop.

In field level trials, we have found switchgrass (cultivar ‘Cave-in-Rock’) yields to be relatively low when starting from long-term, poorly managed stands. However, yields improved to nearly 4.3 Mg ha^-1 (about 2 tons/acre) after two years of fertilization with 112 kg N ha^-1 and weed control. These yield levels are still low, but given that the stands in which the initial work was conducted were thin and poorly managed, we expect that yields can improve in well-managed stands. The one caveat is that the inherent productivity of some highly erodible land is quite low, and high production in these areas, primarily sideslopes, may not be realistic. Additionally, we found evidence of substantial erosion in some established switchgrass stands, a result that was unexpected.

Yields of various germplasm in small plot trials planted in 1997 ranged from 6.4 Mg ha^-1 in 1998 to 11.8 Mg ha^-1 in 1999 as the stands matured and filled in gaps. The highest yielding variety in 1999 was ‘Alamo’, at 17 Mg ha^-1. Alamo and several other lowland ecotypes produced the most biomass, higher than Cave-in-Rock, the normally recommended cultivar for southern Iowa. These trials suggest that higher yields are possible under optimum management and with superior cultivars. A cautionary note is that the lowland cultivars have not experienced a severe winter, and their winter hardiness may not be sufficient under those conditions. In all cases, switchgrass quality appears adequate for a biofuel; variation among cultivars exists, suggesting that further improvements in quality are possible.

Preliminary evaluation of reed canarygrass suggests that two harvests, one in late spring and the other after frost, yield the most biomass. Evaluation of a large collection of germplasm in Iowa and Wisconsin shows that higher yields are possible than those present in currently available cultivars. Quality of reed canarygrass may be problematic: ash, chlorine, and silica are higher than optimum. Further analysis of quality is needed, especially because all data evaluated to date have been collected in central Iowa on soils quite different from those in southern Iowa.

All the field experiments discussed are continuing for at least another year. More substantial discussion of the soil properties of fields and their relationship with biomass yield and quality will be completed over the next year. In addition, new experiments to evaluate the best performing switchgrass cultivars in large strip trials, to test reed canarygrass side-by-side with switchgrass in large plots, and to determine field level yields and quality of reed canarygrass are underway.

Project Personnel

Principal Investigators

E. Charles Brummer Project Coordinator; Biomass Crop Breeding

brummer@iastate.edu 515-294-1415

C. Lee Burras Soil Quality and Management

lburras@iastate.edu 515-294-0559

Michael D. Duffy Agricultural Economics

mduffy@iastate.edu 515-294-6160

Kenneth J. Moore Biomass Crop Production and Utilization

kjmoore@iastate.edu 515-294-5482

Technical Assistance

Michael Barker Biomass Crop Management, Evaluation, and Breeding, and Soil Characterization

Virginie Nanhou Economic Analysis of Biofuel Production

Patricia Patrick Biomass Quality Laboratory Analysis

Mark Smith Biomass Crop Small Plot Harvesting

John Sellers Large Field Plot Assistance

Introduction

Marginal soils, widespread throughout southern Iowa, are unsuited to annual row crop—corn and soybean—production. Much of the landscape in southern Iowa is characterized by heavy, wet soils and significant slopes that allow substantial levels of erosion. On-farm integration of biofuel crops with grain and forage crops and livestock may foster the long-term environmental and economic sustainability required for agricultural systems.

Switchgrass has been chosen as the model herbaceous biofuel crop, and its adaptation to Iowa is well known. Profitable use of biomass crops requires sufficient understanding of agronomic aspects of their culture and economic realities of their production. We intend to assess the productive potential of switchgrass across a range of soil types and landscapes, allowing us to more effectively pinpoint locations where it will perform well.

Reed canarygrass represents another potential biofuel crop, a cool-season grass alternative to switchgrass. With its different growth pattern–it is most productive in spring and fall–and tolerance to both wet and droughty soils, reed canarygrass complements switchgrass in a diversified biofuel program. Its strongly rhizomatous growth habit also make it appealing, particularly on soils on which switchgrass, a bunchgrass, does not form thick stands and erosion is a problem.

The research reported in this report is part of an ongoing project to understand the constraints to biomass production in southern Iowa and to develop production methods that will permit economically viable production of biofuel crops. Although labeled a “final” report, most of the experiments discussed are continuing in the field for one to two more years. Thus, only tentative conclusions are possible at this point. Similarly, the economic analyses are necessarily preliminary and could change as production parameters developed in other phases of this program are implemented on-farm.

In the report, tables for each section follow immediately after the text for that section. Figures are attached at the end of the document, after the appendices.

Research Projects

The research projects that will be discussed in this report are based on three objectives:

I. Economic potential of switchgrass as an agronomic crop for bioenergy

1. Document on-farm costs and resource commitments for switchgrass production

2. Assess regional economic impacts of large-scale switchgrass production

3. Quantification of energy consumption for switchgrass production

II. Switchgrass production in relation to soil variability and environmental quality

1 Landscape and nitrogen effects on switchgrass production potential.

2. Quantification of soil properties and their relation to switchgrass yield and quality, and assessment of the erosion potential in switchgrass fields

III. Evaluate and develop switchgrass and reed canarygrass germplasm for bioenergy production and adaptation to Iowa

1. Switchgrass cultivar evaluation for yield and biofuel quality

2.1. Evaluation of harvest management and varietal performance of reed canarygrass for biofuel

2.2. Evaluate diverse reed canarygrass germplasm and begin breeding new cultivars for bioenergy uses

I. Economics of Switchgrass Production

The preparation of budgets for the costs of producing switchgrass has been completed. This work has been prepared as an Iowa State University Extension Publication. The publication is at the printers.

The publication has the following outline:

What is switchgrass?

Description of the scenarios

General assumptions

Assumptions on input costs

Mchinery

Seed

Herbicides

Fertilizers and lime

Harvesting data

Summary of costs

Summary

The publication is entitled; Costs of Producing Switchgrass for Biomass in Southern Iowa, Iowa State University Extension Publication PM 1866. There were 500 hard copies of the publication order. In addition, the publication will be available electronically on the extension home page.

In addition to the extension publication, this work will be presented at the Fifth Annual Biomass Conference of the Americas.

Since the completion of the budgets reported in the extension publication we have learned more about the production of switchgrass. To continue our work with switchgrass production costs we incorporated some of the changes into new budget estimations. The primary changes that we examined were the impacts of increasing the seeding rates and changing the probability of needing to reseed.

The extension budget estimations were based on using 6 pounds of pure live seed for the seeding rate. In this new series of estimations we increased the seeding rate to 10 pounds pure live seed per acre. The heavier seeding rate was more reflective of current production practices and it is consistent with what has been learned in the field.

The extension budget also assumed a 50% reseeding rate for spring seeded switchgrass and a 25% reseeding rate under a frost seeding system. The heavier seeding rates and experience have shown the probability of reseeding varies. Therefore, we also re-estimated the budgets using a 25, 15, 10 and 0% probability of reseeding.

The new estimations were only for a frost-seeding regime. The previous work showed that in all cases the frost seeding costs of production were lower than the spring seeding. In addition, frost seeding regime was also selected because it has become the establishment technique of choice by producers in southern Iowa. Therefore, we chose to concentrate further analysis on only the frost-seeding system.

Changing the seeding rate from 6 to 10 pounds made very little difference in the final costs per ton. The estimated costs increased by 1% or less, depending on the yield. Summary Tables 1 and 2 show the costs per ton for frost-seeding at 10 pounds per acre with alternative yield levels, alternative probabilities for reseeding, and alternative land charges. Table 1 costs at $75 per acre and a 25% reseeding probability can be compared to Appendix 3 in the extension publication to obtain a comparison of the cost differences for 6 and 10 pound seeding rates.

Summary Table 1 shows that changing the probability of having to reseed causes little change in the costs of production. At the lowest yield, 1.5 tons per acre on cropland, the cost per ton drops from $133.63 with a 25% probability of reseeding, to $130.34 per ton with no reseeding. This is a change of only 2%. The impact lessens the higher the yield.

Appendix I contains all the tables used to create Summary Tables 1and 2. The appendix tables are for the establishment costs, the reseeding costs, and the various yield and reseeding probability scenarios.

The analysis based on heavier seeding rates and alternative assumptions regarding the probability of reseeding do not change the basic conclusions from the initial work. Yield per acre has the greatest impact on the costs per ton. The second greatest impact is attributed to the land charge per acre. With the highest yield, 6 tons per acre, the costs per ton vary from the low $50 range with a $75 per acre land charge to less than $45 per ton with a $25 per acre land charge.

Examining alternative production techniques, reseeding rates, and other production aspects will not appreciably impact switchgrass costs of production. The most important research must be on ways to increase yields. This work has shown that the switchgrass at a 6 ton yield level can be cost competitive for biomass production.

We have completed work on estimating the costs of production for reed canarygrass. These initial budgets will change as we learn more about production techniques and how to manage reed canarygrass.

The most significant reed canary production practices are the following:

· Land preparation is usually done through no till drill following crops and killed sod.

· The seed variety commonly used is Palaton, and seeding rate is 10 to 12 pounds pure live seed per acre.

· Spring or late summer seeding, but late summer (August) seeding preferred.

· No nitrogen application in the establishment year and two nitrogen applications during production years.

· Two harvests per year, in large bales, weighing 1,100 pounds on average.

Summary Table 3 presents the estimated costs for establishing reed canarygrass following cropland and grassland. We assumed a $50 per acre charge for grassland and a $75 per acre land charge for cropland. We assumed that the stand would last for 11 years. Further, we assumed there is no reseeding necessary. Notice that there is no appreciable difference in the establishment cost estimates. This is due to the assumptions used, especially regarding the herbicide choices. These costs would change depending upon the production system chosen by the producer. The costs per ton range from a high of $79.62 per ton for the 3 ton yield on cropland ($75 per acre land charge) to a low of $45.17 per ton for the 6 ton yield on grassland ($50 per acre land charge).

Appendix II contains the tables used to create Summary Table 3. The appendix tables are for the establishment costs and the estimated production costs for 3, 4, and 6 ton yield assumptions.

The costs of producing reed canarygrass follow a similar pattern to switchgrass in that yield is the most important variable in determining the costs per ton. Land charges are the second most important variable. However, as yield increases the effect of the land charge decreases.

Summary Table 1. Summary of frost seeding on cropland, four levels of reseeding probability and two levels of land charge (seeding rate 10lbs/acre).
Scenario	Type of costs	Yield (ton/acre)	25% reseeding probability		15% reseeding probability		10% reseeding probability		0% reseeding probability
Scenario	Type of costs	Yield (ton/acre)	$25	$50	$25	$50	$25	$50	$25	$50

Frost seeding on cropland	Yearly production cost	1.5	143.80	168.80	143.80	168.80	143.80	168.80	143.80	168.80
		3.0	183.90	208.90	183.90	208.90	183.90	208.90	183.90	208.90
		4.0	210.64	235.64	210.64	235.64	210.64	235.64	210.64	235.64
		6.0	264.11	289.11	264.11	289.11	264.11	289.11	264.11	289.11
	Total cost per acre	1.5	171.01	200.44	169.41	198.47	168.61	197.48	167.01	195.51
		3.0	211.11	240.55	209.51	238.57	208.71	237.59	207.11	235.62
		4.0	237.85	267.28	236.25	265.31	235.45	264.32	233.85	262.35
		6.0	291.32	320.76	289.72	318.78	288.92	317.80	287.32	315.83
	Total cost per ton	1.5	114.01	133.63	112.94	132.31	112.41	131.66	111.34	130.34
		3.0	70.37	80.18	69.84	79.52	69.57	79.20	69.04	78.54
		4.0	59.46	66.82	59.06	66.33	58.86	66.08	58.46	65.59
		6.0	48.55	53.46	48.29	53.13	48.15	52.97	47.89	52.64

Summary Table 2. Summary of frost seeding on grassland, four levels of reseeding probability and two levels of land charge (seeding rate 10lbs/acre).
Scenario	Type of costs	Yield (ton/acre)	25% reseeding probability		15% reseeding probability		10% reseeding probability		0% reseeding probability
Scenario	Type of costs	Yield (ton/acre)	$25	$50	$25	$50	$25	$50	$25	$50

Frost seeding on grassland	Yearly production cost	1.5	118.80	143.80	118.80	143.80	118.80	143.80	118.80	143.80