Halophyte Biotechnology Center College of Marine and Earth Studies University of Delaware 700 Pilottown Road Lewes, DE 19958 Growing Biodiesel Fuel and Animal Feed with Saline Irrigation Seashore Mallow (Kosteletzkya virginica) has the evolutionary history and genetic potential for the task. Seashore Mallow features • Grows with saltwater irrigation • Perennial • Morphology similar to soybean • ~18% oil for biodiesel • Residual seed meal ~30% protein • Cellulosic stems for alcohol • Large fleshy roots sequester CO 2 • Grown with traditional farm equipment 1
Transcript
Halophyte Biotechnology Center
College of Marine and Earth Studies University of Delaware
700 Pilottown Road Lewes, DE 19958
Growing Biodiesel Fuel and Animal Feed with
Saline Irrigation
Seashore Mallow (Kosteletzkya virginica) has the evolutionary history and genetic potential for the task.
Seashore Mallow features • Grows with saltwater irrigation • Perennial • Morphology similar to soybean • ~18% oil for biodiesel • Residual seed meal ~30% protein • Cellulosic stems for alcohol • Large fleshy roots sequester CO2 • Grown with traditional farm
equipment
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A. Background - The need for alternative fuel sources to supplement petroleum is crucial, as is the global need for more animal feed. Our ability to meet these needs of a burgeoning world population is uncertain even in a stable global environment. However, the task is made more challenging by the dynamic nature of climate and human influences. High use of fossil fuels contributes to elevated atmospheric carbon dioxide levels. Global warming and changes in weather patterns ensue. Rising temperatures thaw polar ice causing sea level rise that progressively inundates coastal farmland, thereby exacerbating the shortage of land arable for traditional agricultural production. Changing weather patterns disrupt irrigated and non-irrigated farming practices dependent on freshwater. In times of climate change when the human population was small and not a major player in global ecology the simple solution was to migrate to a favorable environment. Now our population size precludes that solution and it is urgent for us to develop and implement human life styles that minimize our negative impact on climate change. Hopefully, each life style change we decide to pursue will be a partial solution to several societal problems at once and not have serious side effects. Our proposed partial solution focuses on farming feed, fuel, and other biological products from a salt-tolerant plant growing on saline land irrigated with coastal sea water. B. One Partial Solution – Our suggestion is a novel salt-tolerant crop, derived from a salt marsh plant. It has the potential to contribute to a reduction in the rate and magnitude of the climate changes, increase our flexibility to deal with change, and expand biofuel and feed supplies. This crop uses saline land and water transforming liabilities in traditional agriculture into assets. Thus, non-arable land becomes arable.
Many land areas are presently not arable because freshwater is
lacking, the soils are naturally saline, or the soils are salty as the result of previous agricultural practices. Many of these areas have abundant saline water available either as surface or ground water. Sea-level rise is producing more salt-afflicted land that can be farmed for an interim period (likely many decades) before that habitat becomes part of a marine environment. These areas in transition obviously have saline water resources suitable for this new crop. In addition, growing salt-tolerant plants for biofuels and livestock feed changes the carbon dioxide balance most favorably if the crop is perennial (energy is not required to work the
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ground and plant them each year). The impact is even greater if they are grown in areas where the current plants are not highly productive or become less so as the climate changes.
Thus, growing the perennial, salt-tolerant biofuel/feed crop provides a
degree of relief for three of the world’s major problems: dependence on petroleum reserves, global warming as a consequence of the elevation of atmospheric greenhouse gases, and our enslavement to freshwater for agriculture. Although we have worked extensively with salt-tolerant pastures, our focus here is on biofuels and a high protein meal byproduct that remains after oil is extracted from the seeds. The cellulosic stems are another resource of biomass and the fleshy root of the perennial plant sequesters increasing amounts of carbon as it enlarges with age. C. Pending Patent – A patent was filed with the United States Office (US-2006-0265945-A1) and the Patent Cooperation Treaty (PCT/US2006/013399) for the “Use of Kosteletzkya for seaside biodiesel fuel.” The abstract appears below.
“The present invention relates to the use of Kosteletzkya in producing oil for use as biodiesel fuel. More specifically, the present invention relates to the use of salinized land or irrigation of non-saline land with saltwater for production of biodiesel fuel, without using valuable freshwater resources.”
The residue from oil extraction is a rich, balanced protein meal with animal feed potential. The cellulosic stems can be a feedstock for alcohol production needed for the esterification process for biodiesel production. The seeds are also a source of gum.
D. Frequently Asked Questions –
1. Why make biodiesel fuel and meal for feed from a salt-tolerant plant such as Seashore Mallow (Kosteletzkya virginica) seed, when we have plenty of soybeans that have a higher yield per acre?
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With the projected growth in world population in the upcoming decades, the demand for food and feed will require that plants now used for biodiesel and the high quality land and freshwater they require will be needed to produce food. The Food and Agriculture Organization (FAO) of the United Nations reported on 9 October 2006 that currently 41 countries are facing food emergencies (Africa -27, Asia/Near East – 10, Latin America – 3, Europe – 1). Among them are Kenya, Pakistan, Mongolia, Lebanon, Colombia, and Chechnya. In the face of these challenges it is not likely that we will be able to sustain the diversion of large areas of rich soil and fresh water assets from food production to produce fuel even in the USA where the population topped 300,000,000 on 18 October 2006 and continues to expand. To meet our fuel production needs, we will need to turn to the rich coastal soils and deltas that have and will become salinized and waterlogged as rising sea levels flood low lying coasts. Biofuel production in America and abroad could be sustainable at a high level if saline soils and water (liabilities in traditional agriculture) available in vast areas around the world were made assets by using a salt-tolerant plant to produce the fuel. Perennial Seashore Mallow has numerous features that contribute to its potential to be a biofuel crop that can substitute for current annual oil seed crops as the human population continues to increase and its obligatory freshwater needs multiply. These features are explained under the next question.
Seashore Mallow flowering and setting seed – first year shoots.
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2. There are other salt-tolerant plants that produce seeds and sturdy stems, why use Seashore Mallow?
The right salt-tolerant plant to develop for biodiesel fuel and animal feed production via saline agronomy is one that combines a number of critical features. Seashore Mallow is a plant whose evolutionary history provides us with a genome that has much of what is desired in a crop that can produce fuel and feed on saline soils with irrigation water too saline for traditional crops. These characteristics have evolved in the stressful habitat of the salt marsh where Seashore Mallow seeds germinate and the plants develop in saline hypoxic conditions. Below are some of those features.
• The seed stores a high percentage of oil. Seashore Mallow seeds contain about 18 -20% oil. This is similar to the average content for freshwater-requiring annual crops such as soybean, corn, and cottonseed. Seashore Mallow has a productive life of about a decade, thus the embedded energy in each harvest compared to that of an annual plant is much less. Fewer gallons of the biodiesel produced are consumed in the seed production.
• The seeds contain oil that has a composition similar to oils that are currently successfully made into biodiesel, therefore, current extracting and processing technology is pertinent. Seashore Mallow oil is very similar in fatty acid composition to oil from cottonseed. Below is a table comparing cottonseed oil and soybean with that extracted from Seashore Mallow.
Seashore Mallow seed oil.
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Characteristics and Composition (%) of Three Seed Crop Oils
Specific gravity 0.92 0.93 - Iodine value 102 105 130 Saponification no. 191 194 191
Cottonseed oil is convertible by transesterification or by saponification and pyrolysis of the sodium soap of the oil to diesel engine fuel. A low Iodine value below 120 is desirable because the European standard (ENH14214) requires it to be less than 120. American standards are not as stringent and may be met in Europe by blending. Because of the similarity of the Seashore Mallow oil to cottonseed oil, the transesterification of the oil yielding glycerin as a byproduct is not a stretch to new technology. Demirbus (2002) describes a method of producing biodiesel from vegetable oils via transesterification in supercritical methanol. (Demirbus, 2002. Biodiesel from vegetable oils via transesterification in supercritical methanol. Energ. Conser. and Manage. 43:2349-576).
Cottonseed oil viscosity is reduced from 33.7 to 3.1 when converted to the methyl ester. It is in the middle range of six
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vegetable oils that were tested and is only slightly higher than no. 2 Diesel which is 2.7.
Peterson et al. (2002) point out the reduced exhaust emissions from biodiesel, its low toxicity, and biodegradability, as well as the need for a continuous flow process methodology which they describe using ethanol as the esterifying alcohol (Peterson et al. 2002. Continuous flow biodiesel production. Appl. Eng. Agricul. 18:5-11).
Seashore Mallow seed pods.
• Seashore Mallow’s seed has a high protein content. Its evolution has produced large protein-rich seeds that contain large amino acid reserves that enable them to become established in very competitive, diverse, nitrogen-limited communities.
Seashore Mallow seeds.
• Seashore Mallow produces sturdy cellulosic stems that hold the flowers above the under-story of grasses. The five petal flowers produce nectar to encourage cross-pollination by insects, but self-fertilize if not pollinated by mid-day and five seeds are produced in the resulting pod. A fleshy perennating root resembles ginseng in morphology.
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Sturdy Seashore Mallow stems.
One year-old Seashore Mallow root system.
• There are few insect or disease pests. The seeds are slow to shatter in the fall. Perhaps the late shattering is a characteristic selected for during the plant’s evolution by the fact that the large oil seed is distributed by floating on the surface of the tidal water and its movement would be inhibited before leaf drop. Likewise, it may be speculated that the plant’s use of oil as the seed energy source could be related to a method for maintaining buoyancy while it floats to new sites to colonize.
• Yields of the selections are low compared to soybeans (about 22 bu./ac. – similar to soybean yields in the 1950s) due to limited breeding and selection to date. Yields do increase with the age of the plants as the crowns produce more stems per crown. One plant we dubbed “Fat Boy” produced 40+ stems after 5 years of growth while being irrigated with 2 to 3 % saltwater (20-30 grams of salt per liter) from the mouth of Delaware Bay. Although “Fat Boy” was more prolific than most, it is not unusual to have 20 stems on plants that old.
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Measurement being taken on Seashore Mallow growing in the winter in a HBC greenhouse in Lewes, Delaware.
• Seashore Mallow seeds have extremely long viability. Seeds stored in a refrigerator for more than a quarter of a century have over 90 % germination. In the wild, a long-lived seed bank is important since in the mature marsh the opportunity for new plants depends on the development of a void in the understory cover.
• The protein content of hulled seeds is about 32%, while whole seeds are approximately 25%. The meal remaining after oil extraction has excellent potential as a nutritious feed supplement similar to that produced from cottonseed meal. Although a feed quality factor to be dealt with in cottonseeds, gossypol was not detected in Seashore Mallow seeds. The amino acid composition of the seeds is displayed in the following table.
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Amino acid mg/g N Amino acid mg/g N Asp 598+ Val 199* Thr 224 Ile 175 Ser 321 Leu 357 Glu 1045+ Tyr 187 Pro 230 Phe 283 Gly 336 Tot.arom-AAs 470
Ala 261 His 172 Cys 166 Lys 278
Met 93 Arg 657+ Tot.S- AAs 259 Try 258
*limiting amino acid, + also the most abundant AAs in cottonseed
The amino acid distribution is good, with valine being the limiting AA which sets amino acid scores at 64 for whole seeds and 72 for hulled.
• Sodium accumulation in the seeds is restricted.
The Na, K, and Ca composition of whole Seashore Mallow seeds is close to that of Great Northern dried beans and similar to soybeans. Pearled barley is much lower in mineral content as seen in the table below. Much of the sodium in the soil is excluded by the Seashore Mallow roots and that absorbed is largely partitioned away from the seeds.
Seed Na K Ca Seashore Mallow 15 1248 205 Great Northern 19 1196 144 Soybean 5 1677 226
Barley, pearled 3 160 16
(Islam, et al. 1982) (data are reported in mg per 100gr)
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• The crop can be easily handled by conventional machinery.
One of the reasons Seashore Mallow was selected for development was that its seeds and plant morphology are similar to that of current crops, hence it doesn’t require that specialized machinery be designed. The way the plant matures and when and how various marketable parts can be harvested are important to the economy of producing the best product.
Planting Seashore Mallow in a no-till setting on the Freeman farm in Sussex County, Delaware.
Seed pods (green unripe and brown ripe).
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• The phenology (when various life stages of its annual production cycle occur) of the plant is similar to other commonly grown crops, such as soybeans, and is easily adapted to traditional farming plans.
The phenology will vary depending on the location and the
genetics of the particular strain of Seashore Mallow. Different genetic strains will respond differently depending on the degree to which the various characters (initiation of spring growth, time when the plant stores food in the fleshy root for the next years growth, time of flowering, initiation of spring growth, etc.) are dependent on fixed genetics, inducible genetics, and/or environment.
Using Delaware Seashore Mallow plants in a saline marsh as
an example: growth begins in late April, flowering begins in early July, seed set and maturation continues with the last maturing in early October, and leaves and stems are dead by the end of the month or early November.
Seashore Mallow seeds were planted on 2.5 acres of Sassafras sandy loam using a conventional row grain planter with sorghum plates in the hoppers. Cultivators and sprayers (for weed control) were standard. The leaves drop off the stems when the seeds mature, thereby simplifying harvest and leaving the seeds rich in oil on the rather woody stems rich in cellulose.
3. What non-wetland or non-agriculturally productive areas can be used to grow this new crop?
The native habitat of seashore mallow is brackish marshes from the mid-Atlantic states of the U.S. into the Southeast and along the Gulf coast. It is not a major component of the wetlands, but occurs as scattered plants mixed primarily with grasses such as Spartina patens.
For ecological and logistical reasons natural marshes are not
the place to harvest seeds. We see four situations where Seashore Mallow fits into saltwater-based agriculture:
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Seashore Mallow in a natural marsh in Delaware.
a. Salinized farmland. Numerous farm fields worldwide have become salinized because of salt accumulation over years of irrigation.
b. Dry farmland with brackish water wells. Many dryland areas have brackish aquifers too saline to support traditional crops.
Using drip irrigation with brackish well water in the Western Desert in Egypt to grow Seashore Mallow.
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c. Sandy coastal deserts. Worldwide there are some 22,000 miles of coastal deserts and many miles of dry estuary coasts such as those of the Mand River Estuary along the Persian Gulf.
Graded coastal desert near Bushehr on the Persian Gulf, Iran.
d. Farmland / aquatic ecosystems transitions. Transition from
aquatic ecosystem to terrestrial ecosystem or the reverse provides opportunities for growing Seashore Mallow. As a perennial halophyte crop capable of growing in poorly drained saline soils, it can provide income for farmers as a renewable fuel source and an animal feed during the transition period. Thus, the liability of traditionally useless farmland is converted to an asset while the land is in transition from one valuable ecosystem type to another. Transition to upland occurs where diking and draining of shallow coastal waters produces new agricultural land and where geologic forces result in a rising coast. The photograph below shows an experimental field of Seashore Mallow in coastal China. That agricultural land has been claimed from the shallow waters of the Yellow Sea using dikes. A transition from waterfowl habitat to aquaculture to saline agronomy (Seashore Mallow and halophytic forage grasses) to traditional upland crop agriculture can occur. Seashore Mallow can provide productivity during the interim between wetland and upland. After a number of years of rainfall (~30 in. yr) has leached the salt from the silt-dominated soils, a
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Seashore Mallow plants on recently diked and dried seabed near Yancheng, China.
succession of traditional crops are planted starting with the most salt-tolerant crops such as cotton and ending with corn and soybeans.
However, projections for most coasts forecast inundation because global warming is stimulating sea-level rise. The more typical global situation is that shown in photographs of Kent County, Delaware soils. Farmlands inundated by saline tidal water are rendered useless for traditional crops.
Field in Kent County Delaware where saltwater intrusion from Delaware Bay has destroyed productivity.
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Salt deposits on the surface of a Kent County, Delaware agricultural field. Scratching the surface reveals the dark soil beneath its salty crust.
In addition to the four situations above we see Seashore Mallow as a possible perennial addition to the annual seed crops often used for food, feed, fuel, and oil in crop rotations. This alternative may become especially useful as new diseases threaten some short-term traditional rotations such as corn/soybeans.
Planting Seashore Mallow in fertile corn and soybean soil on the Freeman farm in Sussex County, Delaware.
E. What is next in the development of Seaside Biodiesel to meet our present and future fuel and feed needs?
The Halophyte Biotechnology Center (HBC) seeks partnerships with others for the tasks described below. In such partnerships the HBC would provide seeds to the partners for Tasks 1, 2, and 5; and partners would
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contribute to the HBC work in Tasks 3 and 4 and the seed production for Tasks 1, 2, and 5. Plant material and information resulting from Tasks 3 and 4 will be provided to the partners to enhance their efforts. Contact Jack Gallagher ([email protected]) or Denise Seliskar ([email protected]) for more information.
TASKS:
1. Oil extraction and esterification - Examine the several methods of extracting oil from samples of seeds on hand and protocols for estrification of that oil; test the efficiency and practicality of these methods. HBC will provide seeds to the partner for testing and technique refinement.
2. Test Seaside Biodiesel fuel – Biodiesel produced from Seashore
Mallow needs to be evaluated in use. HBC will provide the seeds to the partner for biodiesel production.
3. Refine agronomic techniques and production techniques -
Continue the present 2.5 acre production site (2 year-old plants) and establish a second 1.5 acre site under irrigation with Delaware Bay water (~2.5% salt). In addition to the need for seeds for oil extraction, biodiesel production, and subsequent fuel testing, the sites are needed for agronomic testing. Located on the commercial Freeman farm, the 2.5 acre site is the location for testing the use of traditional farm equipment (planters, sprayers, combines, etc.) for the perennial culture of Seashore Mallow. The proposed 1.5 acre site will be irrigated with water from the mouth of Delaware Bay, agronomic protocols especially irrigation efficiency, fertilizer trials, variety comparisons, and salinity effects will be conducted there. Adjacent to the 1.5 acre site, we already have small (8x8 m) saltwater irrigated plots for breeding and for a variety of cultural studies, as was done in the past. The HBC is seeking funding from partners for this developmental work.
Seashore Mallow saltwater experimental plot (8mx8m) at the HBC research facility in Lewes, Delaware.
4. Breeding and selection from populations and tissue culture - The HBC has collected seeds from a range of locations and habitats where Seashore Mallow is indigenous. We plan an evaluation of our collection in order to initiate a breeding program. As can be seen from the photograph of the flower on the first page of this report, the flower parts are large making self-fertilization and cross- fertilization easily conducted in the field.
Collection of pollen from Seashore Mallow.
This fall we found one plant that produced 6 loculate pods
rather than the usual 5. Seeds from that plant were saved for evaluation for the trait and productivity consequences.
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Callus culture of Seashore Mallow with small regenerated embryos.
As the result of somaclonal variation that occurs in the callus stage of tissue culture, seeds from regenerated plants may have mutations of significance for a breeding program to increase yields, seed quality, and agronomic features. Having gathered approximately 500 seeds from these regenerates, we intend to plant and subsequently evaluate them for seed and oil yield, as well as composition and other agronomic qualities. These evaluations of variability are critical in order to gain access to the potential for increasing yield in the short term. The HBC is seeking funding from partners for this work.
Six loculate Seashore Mallow pod and the usual five loculate pod.
Shoots of young regenerating plantlets.
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5. Genetic transformations to improve product quality and agronomic features - We have worked with particle gun and Agrobacterium techniques for gene transfer with Seashore Mallow and the HBC wants to share that experience with partners who wish to carry that phase forward.
Seashore Mallow expressing the GUS gene transferred using a Particle Infusion Gun.
Seashore Mallow expressing the GUS gene transferred via Agrobacterium tumefasciens.
The information presented above focuses on the uses of Seashore
Mallow for biofuels, feed, and sequestration. The Halophyte Biotechnology Center also has other plants ready for salt-tolerant agriculture use in forage (both hay and pasture) for various animals and plants, and for drying biosolids from wastewater treatment plants. If you have interest in these areas please contact either Jack Gallagher ([email protected]) or Denise Seliskar ([email protected]) for more information.
