Winter is the time for making plans for the main growing season. While the sometimes frenetic activity of a farm is invigorating, I really enjoyed the time to study and think for the past few months. January was filled with bouts of mouth-watering pleasure when considering which peppers and melons to eat in August.

One of my main projects was developing detailed plans for what to put in the ground when, and the natural implications for preparing of beds, distributing finished and building new compost, space-time relationships in our little greenhouse, harvest duration, and number and varieties of seeds in stock and to be ordered. I like working with numbers and wanted a way to efficiently go through iterations and refinements of our crop plan. There are so many variables that optimizing one can cause problems elsewhere. As we explore these relationships we find compromises and end up with a plan we have confidence in—knowing that the real world will “interfere.” Plans are useful for organizing time and resources, and signaling to us when we are ahead or behind, but we also know that a change of course may be needed if new information demands it.

Attached below is a spreadsheet file with many linked pages. Each page is drawing attention to a particular issue of farm life. It starts with the decisions of what crops to grow (e.g., tomatoes), and how much of each we want (e.g., pounds per week). The amount of food can be translated into approximate areas (e.g., 200 square feet). Each plant that gets put in the ground starts as a seed, so we can estimate backwards from harvest time to seed time and therefore greenhouse space if required (e.g., tomatoes harvested in early July begin in the greenhouse in early March). When clearing an area for a vegetable crop, the cover crop sown in the fall is removed. This becomes material for compost piles that are applied a year later. Does our crop plan allow cover crops to fix enough nitrogen and produce enough carbon to make sufficient compost for our site (ca. 2600-5200 lbs per year)?

The spreadsheet is made specifically for Brookside Farm, but could readily be modified to suit farms of different sizes and locations. It is modeling the annual pattern of intensive vegetable cultivation with cover crops. If you find this useful for your situation please let us know.

ENERGY GARDEN CROPS

The following is a list of the crops currently growing in the Sebastopol Energy Garden as well as those selected for the 2008 growing season. The crops have been categorized by the major anthropocentric functions they fulfill and the morphological plant parts of use. By assessing the crops in this manor we can correlate them with their appropriate zone within the garden. In addition to providing the common names and functions of the selected crops, optimal planting conditions are provided for annuals, and background information is provided for profile crops.

PROFILE CROPS

Profile Crops support the goals of the Sebastopol Energy Garden by offering local means of energy security, food production, soil improvement, and water conservation. These crops are most often cultivated in Zone 2 of the property.

Energy Security: Crops that function as potential sources of energy are those high in calories (carbohydrates and lipids) grown for human consumption, biofuel production, and anaerobic digestion.

Food Production: Crops grown as local sources of food are chosen as profile crops if they display stacked functions, are area-and-weight-efficient crops, or are beneficial non-conventional crops.

Soil Improvement: Crops which improve the soil are those capable of accumulating large quantities of minerals and producing large amounts of carbon. These crops provide the required materials for onsite preparation of compost and mulch, as well as function biologically in the improvement of the health of the soil.

Water Conservation: Crops grown for the purpose of water conservation are those which require low amounts of water or those which improve the quality of water by functioning as hyperaccumulators of water contaminants.

The following is the background information of selected profile crops. They are organized by function in the same order as above.

 

 

Switchgrass: (Panicum virgatum) is a perennial grass native to North America. Because it is native, switchgrass is resistant to many pests and plant diseases as well as being very tolerant of poor soils, flooding and drought. It is easily germinated from seed, and capable of producing high yields with very low applications of fertilizer. Switchgrass makes for a great energy crop because it grows fast, capturing lots of solar energy and turning it into chemical energy which it stores as cellulose. Switchgrass reaches its full yield potential after the third year planted, producing approximately 6 to 8 tons per acre; that is 500 gallons of ethanol per acre. At maturity, widely spaced switchgrass plants can measure 20 inches in diameter at ground level. Switchgrass has a huge, permanent root system that penetrates over 10 feet into the soil, and weighs as much as the above-ground growth from one year. It also has many fine, temporary roots. All these roots improve the soil by adding organic matter, and by increasing soil water infiltration and nutrient-holding capacity.

 

Miscanthus: (Miscanthus x giganteus) is a tall perennial grass that has been evaluated in Europe during the past 5-10 years as a new bioenergy crop. Like other energy crops, the harvested stems of miscanthus may be used as fuel for production of heat and electric power, or for conversion to other useful products such as ethanol. Because the crop is a sterile hybrid it is established by planting pieces of the root, called rhizomes, which develop into the mature plant. Miscanthus is ready for harvest within 2 years and yields continue to improve until they level off around the 5th or 6th year. Speculating from European data, under typical agricultural practices over large areas, an average of about 3 tons per acre dry weight may be expected at harvest time.

Miscanthus exhibits:

Relatively high yields 8-15 t/ha (3-6 t/acre) dry weight.

Low moisture content (as little as 15-20%).

Annual harvests, providing a regular yearly income for the grower.

Relatively good energy balance and output/input ratio

Low mineral content, which improves fuel quality.

Jerusalem Artichoke: (Helianthus tuberosus L.) is an annual flowering plant native to North America. It grows 1-3 meters tall with flowers similar to the sunflower but much smaller (4-8cm in diameter). Jerusalem artichokes are grown throughout the temperate world for their tubers, which are used as a root vegetable. The tubers are gnarly and uneven, vaguely resembling ginger root, with a crisp texture when raw. Unlike most tubers, but characteristic of members of Asteraceae (Sunflower family to which it belongs), the tubers store the carbohydrate inulin instead of starch. The inulin is isolated on the basis of its high solubility in hot water; by boiling the tuber and allowing it to cool polysaccharides can be extracted. Yields tend to vary with soil conditions, cultivar and season, but fresh weights in excess of 100 tons per hectare have been recorded, which is around 8 tons per hectare of sugar. For this reason, Jerusalem artichoke tubers are an important source of energy.

 

Sugar Beet: (Beta vulgaris L.), a member of the Chenopodiaceae family, is a biennial plant whose root contains a high concentration of sucrose, accounting for 30% of the world's sugar production. During its first growing season, it produces a large (1–2 kg) storage root whose dry mass is 15–20% sucrose by weight. Sugar beets have the potential to produce 30-40 tons of roots per hectare under non-irrigated conditions and 50-70 tons per hectare with irrigation. The research done by the Agronomic University of Bucharest in the South zone of Romania has recorded ethanol production at 5,508 liter ethanol per hectare. The sugar beet may become, in the future an important energy crop.

 

Soybean: (Glycine max) is an annual legume (Fabaceae). It may grow prostrate, not growing higher than 20 cm (7.8 inches), or stiffly erect up to 2 meters (6.5 feet) in height. Soybeans provide the principal oil being utilized for biodiesel in North America. To produce soybean oil, the soybeans are cracked, adjusted for moisture content, rolled into flakes and solvent-extracted with commercial hexane. According to the U.S. Department of Agriculture's (USDA) Farm Service Agency, one bushel of soybeans yields approximately 1.4 gallons of biodiesel. Soybeans contain about 20% oil, so it takes almost 7.3 pounds of soybean oil to produce a gallon of biodiesel. In addition soybeans enhance the nitrogen content of the soil and provide the soil with many nutrients.

 

Dale Sorghum: (Sorghum bicolor L.) is an annual tropical grass that is easily propagated from seed. A prolific producer, averaging about twelve feet in height at maturity; sorghum is a short rotation crop, meaning that it can be harvested multiple times throughout the year. Sweet sorghums have been selected for their high sugar content and are normally grown for molasses production. Dale Sorghum is a drought resistant variety of sweet sorghum that requires less intensive irrigation. It is an early maturing (115 day) variety with superior disease resistance to many older common varieties and is well adapted for syrup production, which can be converted to methane or ethanol. It produces on average 40 tons per hectare of cane, 25 tons per hectare of juice, and provides a grain yield of 2-6 tons per hectare. It is estimated that for each ton of cane yield 40 liters of ethanol can be produced, that is 1600 liters of ethanol per hectare of Sorghum.

Peredovik Sunflower: (Helianthus annuus) is an energy and protein rich annual that at maturity (12 weeks after germination), reaches a height of 4 feet. Second only to soybeans, sunflower oilseed varieties are the most important source of high-quality vegetable oil in the world. This Russian cultivar produces small, black seeds that yield more oil than most other sunflowers (approximately 952 liters of oil per hectare). While typical sunflower seeds contain 25–35% oil, the peredovik sunflower can contain up to 50% oil. According to the Duke handbook of Energy Crops, a hundred kilograms of dry seed will yield about 40 kilograms of oil, 15–20 kilograms of hulls, and 40 kilograms of proteinaceous meal.

Rapeseed: (Brassica napus) contains erucic acid, which is mildly toxic to humans in large doses. The word "canola" is derived from "Canadian oil, low acid;" it is a particular cultivar of Rapeseed developed to produce low amounts of erucic acid. Rapeseed is the third leading source of vegetable oil after soybean and oil palm, and the world's second leading source of protein meal. The oil content runs 42.0–44.5%, and oil yields of more than 1 MT/ha are reported. Due to this high oil production per unit of land area rapeseed oil is the preferred oil stock for biodiesel production in most of Europe. The crop is particularly of interest because it not only produces higher yields during the autumn growing period but the oil percentage of the harvest is higher as well.

Flax: (Linum usitatissimum L.) is an erect annual with slender stems that is grown for its seed and fiber. It is not generally a crop that is spoken of in relation to alternative fuel sources; however, there are groups looking into the possibility of using the long tough stem fibers of oilseed flax as feedstock for large scale burners. Flax seeds contain 20–30% protein, and are the source of linseed oil. Flax straw has a per ton heating value similar to soft coal that is much greater than other crop residues. Not only is the straw cheaper than conventional fuels; it is also carbon neutral fuel; meaning that the plant takes carbon from the air during the growing season to produce the straw, reducing the amount of greenhouse gasses in the atmosphere. With seed yields of 1000–4000 kilograms per hectare, and reported oil content of 34–37%, flax has the potential to yield 1500 kilograms of oil per hectare.

Safflower: (Carthamus tinctorius) is a member of Asteraceae; it is a thistle-like plant growing 30-150 cm tall with globular flower heads (capitula) of commonly, yellow, orange or red flowers. . Safflower is grown exclusively for its oil which is high in essential unsaturated fatty acids. Oil yields approach 50%, leaving a meal with 21% protein, 35% fiber, and 1-3% fat, a great source of nutrients for feedstock. According to Khoshoo (1982), the BTU value per gallon of safflower oil is 130,730. The crops viscocity of 32.7 has been described in concern; however, tractors were run on 100% safflower oil for over 90 hours to cut hay and cultivate in Australia, and diesel engines fueled with safflower oil were run more than 700 hours in Idaho with no obvious difference ascribed. It has been reported that for every 212-262 gallons of extractable oil harvested per hectare 25 gallons of fuel is required. (Khoshoo, 1982). High oleic safflower oil is virtually free of sulfur.

Castor Bean: (Ricinus communis), a member of Euphorbiaceae, has been cultivated for centuries because of the energy rich oil it produces in its seeds. The seeds contain between 40% and 60% oil that is rich in triglycerides. The crop grows 3 to 10 ft, producing several branches with terminal spikes that are 6 to 12 in. long. Each spike bears 15 to 80 capsules, which contain within each of them three seeds. Yields of about 2,200 lb/acre have been reported in Nebraska tests. Average production is estimated at 750 kilos per hectare. The seeds and roots of the plant contain high concentrations of ricin, a poison, which is also present in lower concentrations throughout the plant making it a great gopher poison. The crop is also harmful to humans and livestock and for this reason caution must be taken in disposal of the crop after cultivation.

Sesame: (Sesamum indicum L.) belongs to the Pedaliaceae family. It is an annual herb that can grow to a height of 60 inches. The seeds that it produces, which have been estimated to achieve yields of as much as 2,300 lb/acre under irrigation in California, consist of approximately 50% oil and 25% protein. Sesame seeds contain 825 calories per cup of which 644 are from fat. Among edible oils, sesame oil has the highest antioxidant content, namely due to the presence of the compound sesamin; this allows for greater shelf life plus improved flavor. In addition the seeds with hulls are rich in calcium (1.3%) and provide a valuable source of minerals for both human and livestock consumption.

Quinoa: (Chenopodium quinoa) is grown primarily for its highly nutritious edible seeds, which are small yellow flattened spheres, approximately 1.5 to 2 millimeters in diameter; however, the leaves of the plant can also be eaten. The seed coat contains bitter saponin compounds that must be removed before human consumption, but it is this bitter pericarp that keeps the crop nearly untouched by birds. In addition to containing a balanced set of essential amino acids for humans, quinoa’s protein content (12%–18%) is very high, making it an unusually complete foodstuff; this means it takes less quinoa protein to meet one's needs than it does wheat protein. Quinoa is a good source of dietary fiber and phosphorous and is high in magnesium and iron; it is gluten free and considered easy to digest. There are about 1480 calories in one pound of quinoa flour or seeds (55.3% carbohydrates, 13.1% protein, 5.8% fat, 13.6% fiber, 9.3% water, and 2.9% minerals).

Oats: (Avena sativa) are an annual grass that reach 1.3 meters in height. Producing an average of 125 bushels per acre, which is 8,000-12,000 pounds per acre of biomass, oats are primarily grown for livestock feed; in fact less than 5% of the total production in this country is for human consumption (mainly as oat flour). Oat is the only cereal containing a globulin or legume-like protein, avenalins, as its major (80%) storage protein. The protein content of the hull-less oat kernel, or groat, ranges from 12–24%, the highest among cereals. Oats help conserve soil, they require relatively less chemical fertilizers, pesticides and herbicides; they reduce water contamination by agricultural chemicals, and provide nutritional benefits to both humans and animals.

Corn: (Zea mays L.), the single largest U.S. crop, is increasingly being used as a biomass fuel. It is currently harvested from 30 million hectares within the United States, which is almost ¼ of all the harvested cropland in the country. The average yield of moist corn grain is 8600 kilograms per hectare; that is approximately 150 bushels per acre. According to the National Corn Growers Association, 1.3 billion bushels of corn were allocated towards ethanol production in 2004. David Pimentel, a professor from Cornell estimates that one acre of U.S. corn can be processed into about 328 gallons of ethanol, but planting, growing and harvesting that much corn requires close to 140 gallons of fossil fuels and costs $347 per acre; that is $1.05 per gallon of ethanol before the corn even moves off the farm, meaning that 70% more energy is required to produce ethanol from corn than the energy that ethanol contains. No research has been done; however, as to whether corn may serve as a sustainable energy crop when grown organically and at a much smaller scale. Corn residues, including the stalk and cob may also prove useful in future energy production.

Energy Inputs to Corn Production

Nitrogen fertilizers (all fossil energy)

Phosphate, potash, and lime (mostly fossil energy)

Herbicides and insecticides (all fossil energy)

Fossil fuels: diesel, gasoline, petroleum gas, and natural gas

Electricity (almost all fossil energy)

Transportation (all fossil energy)

Corn seeds and irrigation (mostly fossil energy)

Infrastructure (mostly fossil energy)

Labor (mostly fossil energy)

Potato: (Solanum tuberosum) a member of Solanaceae, ranks with wheat and rice as one of the most important staple crops in the human diet around the world.Within 10 g of the tubers are 80 calories (320 kJ). A medium potato (150g/5.3 oz) with the skin provides 27 mg vitamin C (45% of the Daily Value), 620 mg of potassium (18% of Daily Value), 0.2 mg vitamin B6 (10% of Daily Value) and trace amounts of thiamin, riboflavin, folate, niacin, magnesium, phosphorus, iron, and zinc. Moreover, the fiber content of a potato with skin (2 grams) equals that of many whole grain breads, pastas, and cereals.

Buckwheat: (Fagopyrum esculentum) is a short season crop that does well on poor, sandy, somewhat acidic soils. Plants will begin blooming in about 40 days from seeding, with the first seeds mature after an additional 40 days. This rapid production allows for many harvests throughout the year makes the crop ideal for growing as a local source of calories. The seed is an achene, similar to a sunflower seed, with a hard outer shell and soft inner meat. Most of the buckwheat grain utilized as food for humans is marketed in the form of flour but whole grain may be used in poultry scratch feed mixtures as they are high in protein. As well as being a food crop, buckwheat is used for its biomass.

Amaranth: (Amaranthus sp.) with 60 recognized species, makes up its own family, Amaranthaceae. The herbaceous annual grows 5 to 7 feet, with broad leaves and a showy flower head of small, red or magenta, flowers. The seed heads resemble corn tassels, but are somewhat bushier, composed of tiny (1/32"), lens shaped seeds that are a golden, creamy, tan color. Amaranth resists heat and drought; it has no major disease problems, and is among the easiest of plants to grow. Each plant is capable of producing 40,000 to 60,000 seeds that like buckwheat and quinoa, contain protein that is unusually complete for plant sources. The leaves also are a very good source of vitamins including vitamin A, vitamin B6, vitamin C, riboflavin, and folate, and dietary minerals including calcium, iron, magnesium, phosphorus, potassium, zinc, copper, and manganese. Several studies have shown that like oats, amaranth seed or oil may benefit those with hypertension and cardiovascular disease.

Black Salsify: (Scorzonera hispanica) is a member of Asteraceae cultivated for its calorie rich black taproot which grows up to one meter long and up to 2 cm in diameter. In ½ cup of Black Salsify are 50 calories; potassium, calcium, phosphorus, iron, sodium, and vitamins A, B1, E and C are also present. In addition to the root, the foliage is edible and functions as a great nutrient source for livestock as well as a source of salad greens for humans. Because the crop is relatively untroubled by pests and cold tolerant it makes an easy to manage crop for the organic farmer.

Parsnip: (Pastinaca sativa) a member of Apiaceae, offers a great source of calories during the winter while the rest of the garden is dormant. Parsnips are very frost resistant; in fact, frost is necessary to develop the flavor and nutrients for the hardy root crop. In 100 g of parsnip root are 55 calories; that is 230 kJ of energy. Parsnips are richer in vitamins and minerals than its close relative the carrot, and in addition to providing calories to the diet, they are a good source of fiber, folate, magnesium, potassium (600 mg per 100 g), Vitamins C and E, calcium, iron, thiamin, riboflavin, niacin, and B6.

Barley: (Hordeum vulgare) a member of Poaceae, can be grown in both spring and autumn. It retains yields under harsh conditions and poor soils where other grains don’t produce well. Barley contains twice as many fatty acids as wheat which accounts for its 10% higher calorie count. In addition barley contains 68% more thiamin, 250% more riboflavin and 38% more lysine than wheat, giving barley a more balanced protein. One hundred grams of barley contains 135 calories and provides 54.5% of the recommended daily fiber (both soluble and insoluble fiber). It has been documented in both the Journal of the American College of Nutrition and the American Journal of Clinical Nutrition that increase barley consumption correlates with cholesterol reduction.

Lentil: (Lens culinaris) a member of Fabaceae, grows 15 inches tall and produces many pods which contain within each of them two seeds. Estimated yields in excess of 2,000 lb/acre have been achieved at small levels of production. Protein content of the crop ranges from 22 to 35%, but the nutritional value is low because lentil is deficient in the amino acids methionine and cystine. In 100g of lentil are 371 calories. Apart from a high level of proteins, lentils also contain dietary fiber, vitamin B1, and minerals. Red (or pink) lentils contain a lower concentration of fiber than green lentils (11% rather than 31%). Lentil provides more folic acid than any other unfortified food. One cup of cooked lentils contains 90% of the recommended daily allowance. As a result consuming lentil effectively reduces homocystein blood levels, reducing risk for heart problems.

Rye: (Secale cereale) a member of Poaceae, grows in both spring and august and function as a cover crop in addition to providing carbon and calories for the small scale farm. Yields of 70 to 80 bu/acre can be obtained with good management. The food value of rye consists of 1.5% fat, 73.9% complex carbohydrates, and 12.2% protein. The energy content of the grain is intermediate to that of barley and wheat. It contains 335 calories within100g (1402kj). Although rye flour does not develop true gluten, it is the only cereal grain other than wheat to have the necessary qualities to make bread.

 

 

 

 

Millet: (Panicum miliaceum) a member of Poaceae, grows well on poorly fertilized and dry soils and fits well in hot climates with short rainfall periods and cool climates with brief warm summers. For this reason it is considered a staple food crop among 1/3 of the world’s population. Millet is highly nutritious, non-glutinous and like buckwheat and quinoa, is not an acid forming food so it is easy to digest. In fact, it is considered to be one of the least allergenic and most digestible grains available and it is a warming grain so will help to heat the body in cold or rainy seasons and climates. Millets are rich in B vitamins, especially niacin, B6 and folacin, calcium, iron, potassium, magnesium, and zinc. The seeds are also rich in phytochemicals, including Phytic acid, which is believed to lower cholesterol, and Phytate, which is associated with reduced cancer risk. Contained within 100g of millet seed are 228 calories with 66,000 to 81,000 seeds/lb. Each seed contains nearly 15% protein. Yields up to 2500 to 2800 lb/acre are realistic for this climate.

 

Fababean: (Vicia faba ) is the plant for which the bean family, Fabaceae, was named. At about 25% protein, the crop is very nutritious and high in energy, and is frequently cultivated for human and livestock consumption. Average yields of 2261 lbs/acre have been achieved under irrigation. Frost hardy to about 7°F, it is one of the most important winter crops for human consumption in the Middle East. More so than a food crop, fababeans are the most efficient of all legumes at fixing nitrogen within the soil. The crop is capable of fixing up to 200 pounds of nitrogen per acre. In addition their extensive root system breaks up soil to 2 feet deep, and brings up soluble nutrients from 10 feet deep.

Alfalfa: (Medicago sativa) is a cool season perennial legume, growing to a height of 1 meter. Like other legumes, its root nodules contain bacteria, Sinorhizobium meliloti, capable to fix nitrogen (estimated to fix 83–594 kg N/ha/yr), producing a high-protein feed, giving it the highest feeding value of all common hay crops. Forage yields are 5–75 MT/ha per year (with 8–12 cuttings per year). Seed yields are 186–280 kg/ha annually. Alfalfa grows well in the cool months, producing enough vegetation to yield the energy equivalent of 2 to 7 barrels of oil per acre. Basing estimates on average alfalfa hay yields, participants at the Fourth Annual Alfalfa Symposium concluded that we could get nearly a ton of leaf protein per acre from alfalfa. This would mean 55 million tons of protein from 62.5 million acres—about 10 times what Americans need in their diet. Residues remaining after protein extraction would yield the equivalent of 250 million barrels of oil in residues.

Hairy Vetch: (Vicia villosa) a member of Fabaceae, is the only vetch species that can be fall-seeded and reach maturity the following July. Capable of enriching the soil with nitrogen up to 60 to 120 lb/acre, and aerating soil up to depths of 30-85 cm, the legume is used primarily for soil improvement. Hairy vetch is also said to facilitate the availability of potassium to other, shallower-rooted, crops The protein content of vetch hay ranges from 12 to 20%; however, and can function as a beneficial food source for livestock. Vetch produces a hay yield of 1.5 to 3.5 ton/acre dry weight.

White Clover: (Trifolium repens) a member of Fabaceae, is the world’s most widely grown clover. It is often under sown with cereals to provide a perennial source of nitrogen and increase their yield. White clover yields of 100 lb of N/acre have been documented. White clover can be “frost seeded” (in early spring when the soil is still frosted) into existing grass pastures to improve pasture production and quality. It is highly nutritious and palatable and aside from improving the soil of the pasture is offers a source of winter forage for livestock. The protein content of white clover will exceed 15% and the digestibility 70%. Dry matter yields will range from 2000 to 4000 pounds per acre per season depending mainly on soil moisture. The crop tolerates trampling and mowing, and can therefore be seeded as an alternative to conventional lawns.

Comfrey: (Symphytum officinale L.) is a prolific perennial herb belonging to the Borage family (Boraginaceae) that has long been recognized by organic gardeners for its great usefulness and versatility, both medicinally and as a fertilizer. Because the majority of comfrey under cultivation is hybridized, it is typically propagated from root cuttings. It is a sturdy plant, reaching a height of 2 to 3 1/2 feet with very large, hairy lower leaves, as much as 15 to 20 inches long. Its roots draw nutrients from deep in the soil to produce the energy rich foliage that offers many methods of application as a fertilizer.

Comfrey offers many uses as a fertilizer:

- Comfrey as a compost activator

- Comfrey as liquid fertilizer

- Comfrey as a mulch

- Comfrey as a potting mixture ingredient

Switchgrass: (Panicum virgatum) is a perennial grass native to North America. Because it is native, switchgrass is resistant to many pests and plant diseases as well as being very tolerant of poor soils, flooding and drought. It is easily germinated from seed, and capable of producing high yields with very low applications of fertilizer. Switchgrass makes for a great energy crop because it grows fast, capturing lots of solar energy and turning it into chemical energy which it stores as cellulose. Switchgrass reaches its full yield potential after the third year planted, producing approximately 6 to 8 tons per acre; that is 500 gallons of ethanol per acre. At maturity, widely spaced switchgrass plants can measure 20 inches in diameter at ground level. Switchgrass has a huge, permanent root system that penetrates over 10 feet into the soil, and weighs as much as the above-ground growth from one year. It also has many fine, temporary roots. All these roots improve the soil by adding organic matter, and by increasing soil water infiltration and nutrient-holding capacity.

Miscanthus: (Miscanthus x giganteus) is a tall perennial grass that has been evaluated in Europe during the past 5-10 years as a new bioenergy crop. Like other energy crops, the harvested stems of miscanthus may be used as fuel for production of heat and electric power, or for conversion to other useful products such as ethanol. Because the crop is a sterile hybrid it is established by planting pieces of the root, called rhizomes, which develop into the mature plant. Miscanthus is ready for harvest within 2 years and yields continue to improve until they level off around the 5th or 6th year. Speculating from European data, under typical agricultural practices over large areas, an average of about 3 tons per acre dry weight may be expected at harvest time.

Miscanthus exhibits:

1. Relatively high yields 8-15 t/ha (3-6 t/acre) dry weight.

2. Low moisture content (as little as 15-20%).

3. Annual harvests, providing a regular yearly income for the grower.

4. Relatively good energy balance and output/input ratio

5. Low mineral content, which improves fuel quality.

Jerusalem Artichoke: (Helianthus tuberosus L.) is an annual flowering plant native to North America. It grows 1-3 meters tall with flowers similar to the sunflower but much smaller (4-8cm in diameter). Jerusalem artichokes are grown throughout the temperate world for their tubers, which are used as a root vegetable. The tubers are gnarly and uneven, vaguely resembling ginger root, with a crisp texture when raw. Unlike most tubers, but characteristic of members of Asteraceae (Sunflower family to which it belongs), the tubers store the carbohydrate inulin instead of starch. The inulin is isolated on the basis of its high solubility in hot water; by boiling the tuber and allowing it to cool polysaccharides can be extracted. Yields tend to vary with soil conditions, cultivar and season, but fresh weights in excess of 100 tons per hectare have been recorded, which is around 8 tons per hectare of sugar. For this reason, Jerusalem artichoke tubers are an important source of energy.

Kenaf: (Hibiscus cannabinus) is considered one of the most promising alternatives to virgin, soft, and hard woods for paper production. An herbaceous annual related to cotton and okra, kenaf is a member of Malvaceae (Mallow family).

USDA chose kenaf from among five hundred candidates as the most promising non-wood fiber for pulp and paper production for several reason:

· Rapid growth: Kenaf reaches 12-18 feet in 150 days, while southern pine (A species commonly grown on tree plantations) must grow 14 to 17 years before it can be harvested.

· High yield: Kenaf yields 5-10 tons of dry fiber per acre, or approximately 3 to 5 times as much as southern pine.

· Exceptional papermaking characteristics: Less chemicals, heat and time are required to pulp kenaf fibers because they are not as tough as woodpulp and contain less lignin (an average kenaf plant contains only 9% lignin, while southern pine contains 29% lignin.

· Opportunities also exist for the production of renewable feedstock from Kenaf, as it is such a fast growing plant.

Sugar Beet: (Beta vulgaris L.), a member of the Chenopodiaceae family, is a biennial plant whose root contains a high concentration of sucrose, accounting for 30% of the world's sugar production. During its first growing season, it produces a large (1–2 kg) storage root whose dry mass is 15–20% sucrose by weight. Sugar beets have the potential to produce 30-40 tons of roots per hectare under non-irrigated conditions and 50-70 tons per hectare with irrigation. The research done by the Agronomic University of Bucharest in the South zone of Romania has recorded ethanol production at 5,508 liter ethanol per hectare. The sugar beet may become, in the future an important energy crop.

Soybean: (Glycine max) is an annual legume (Fabaceae). It may grow prostrate, not growing higher than 20 cm (7.8 inches), or stiffly erect up to 2 meters (6.5 feet) in height. Soybeans provide the principal oil being utilized for biodiesel in North America. To produce soybean oil, the soybeans are cracked, adjusted for moisture content, rolled into flakes and solvent-extracted with commercial hexane. According to the U.S. Department of Agriculture's (USDA) Farm Service Agency, one bushel of soybeans yields approximately 1.4 gallons of biodiesel. Soybeans contain about 20% oil, so it takes almost 7.3 pounds of soybean oil to produce a gallon of biodiesel. In addition soybeans enhance the nitrogen content of the soil and provide the soil with many nutrients.

Dale Sorghum: (Sorghum bicolor L.) is an annual tropical grass that is easily propagated from seed. A prolific producer, averaging about twelve feet in height at maturity; sorghum is a short rotation crop, meaning that it can be harvested multiple times throughout the year. Sweet sorghums have been selected for their high sugar content and are normally grown for molasses production. Dale Sorghum is a drought resistant variety of sweet sorghum that requires less intensive irrigation. It is an early maturing (115 day) variety with superior disease resistance to many older common varieties and is well adapted for syrup production, which can be converted to methane or ethanol. It produces on average 40 tons per hectare of cane, 25 tons per hectare of juice, and provides a grain yield of 2-6 tons per hectare. It is estimated that for each ton of cane yield 40 liters of ethanol can be produced, that is 1600 liters of ethanol per hectare of Sorghum.

Peredovik Sunflower: (Helianthus annuus) is an energy and protein rich annual that at maturity (12 weeks after germination), reaches a height of 4 feet. Second only to soybeans, sunflower oilseed varieties are the most important source of high-quality vegetable oil in the world. This Russian cultivar produces small, black seeds that yield more oil than most other sunflowers (approximately 952 liters of oil per hectare). While typical sunflower seeds contain 25–35% oil, the peredovik sunflower can contain up to 50% oil. According to the Duke handbook of Energy Crops, a hundred kilograms of dry seed will yield about 40 kilograms of oil, 15–20 kilograms of hulls, and 40 kilograms of proteinaceous meal.

Peredovik sunflowers provide stacked functions including:

1. Food in the form of filtered oil

2. Oil that can be converted to biodiesel

3. The remaining press cake from expelling can be fed to livestock

4. The flowers are bee forage

5. The dried stalk is a carbon component for compost

Flax: (Linum usitatissimum L.) is an erect annual with slender stems that is grown for its seed and fiber. It is not generally a crop that is spoken of in relation to alternative fuel sources; however, there are groups looking into the possibility of using the long tough stem fibers of oilseed flax as feedstock for large scale burners. Flax seeds contain 20–30% protein, and are the source of linseed oil. Flax straw has a per ton heating value similar to soft coal that is much greater than other crop residues. Not only is the straw cheaper than conventional fuels; it is also carbon neutral fuel; meaning that the plant takes carbon from the air during the growing season to produce the straw, reducing the amount of greenhouse gasses in the atmosphere. With seed yields of 1000–4000 kilograms per hectare, and reported oil content of 34–37%, flax has the potential to yield 1500 kilograms of oil per hectare.

Corn: (Zea mays L.), the single largest U.S. crop, is increasingly being used as a biomass fuel. It is currently harvested from 30 million hectares within the United States, which is almost ¼ of all the harvested cropland in the country. The average yield of moist corn grain is 8600 kilograms per hectare; that is approximately 150 bushels per acre. According to the National Corn Growers Association, 1.3 billion bushels of corn were allocated towards ethanol production in 2004. David Pimentel, a professor from Cornell estimates that one acre of U.S. corn can be processed into about 328 gallons of ethanol, but planting, growing and harvesting that much corn requires close to 140 gallons of fossil fuels and costs $347 per acre; that is $1.05 per gallon of ethanol before the corn even moves off the farm, meaning that 70% more energy is required to produce ethanol from corn than the energy that ethanol contains. No research has been done; however, as to whether corn may serve as a sustainable energy crop when grown organically and at a much smaller scale. Corn residues, including the stalk and cob may also prove useful in future energy production.

Energy Inputs to Corn Production

1. Nitrogen fertilizers (all fossil energy)

2. Phosphate, potash, and lime (mostly fossil energy)

3. Herbicides and insecticides (all fossil energy)

4. Fossil fuels: diesel, gasoline, liquified petroleum gas, and natural gas

5. Electricity (almost all fossil energy)

6. Transportation (all fossil energy)

7. Corn seeds and irrigation (mostly fossil energy)

8. Infrastructure (mostly fossil energy)

9. Labor (mostly fossil energy)

Buckwheat: (Fagopyrum esculentum) is a short season crop that does well on poor, sandy, somewhat acidic soils. Plants will begin blooming in about 40 days from seeding, with the first seeds mature after an additional 40 days. The seed is an achene, similar to a sunflower seed, with a hard outer shell and soft inner meat. Most of the buckwheat grain utilized as food for humans is marketed in the form of flour but whole grain may be used in poultry scratch feed mixtures as they are high in protein. As well as being a food crop, buckwheat is used for its biomass.

Comfrey: (Symphytum officinale L.) is a prolific perennial herb belonging to the Borage family (Boraginaceae) that has long been recognized by organic gardeners for its great usefulness and versatility, both medicinally and as a fertilizer. Because the majority of comfrey under cultivation is hybridized, it is typically propagated from root cuttings. It is a sturdy plant, reaching a height of 2 to 3 1/2 feet with very large, hairy lower leaves, as much as 15 to 20 inches long. Its roots draw nutrients from deep in the soil to produce the energy rich foliage that offers many methods of application as a fertilizer.

Comfrey offers many uses as a fertilizer:

1. Comfrey as a compost activator

2. Comfrey as liquid fertilizer

3. Comfrey as a mulch

4. Comfrey as a potting mixture ingredient

Quinoa: (Chenopodium quinoa) is grown primarily for its highly nutritious edible seeds, which are small yellow flattened spheres, approximately 1.5 to 2 millimeters in diameter; however, the leaves of the plant can also be eaten. The seed coat contains bitter saponin compounds that must be removed before human consumption, but it is this bitter pericarp that keeps the crop nearly untouched by birds. In addition to containing a balanced set of essential amino acids for humans, quinoa’s protein content (12%–18%) is very high, making it an unusually complete foodstuff; this means it takes less quinoa protein to meet one's needs than it does wheat protein. Quinoa is a good source of dietary fiber and phosphorous and is high in magnesium and iron; it is gluten free and considered easy to digest. There are about 1480 calories in one pound of quinoa flour or seeds (55.3% carbohydrates, 13.1% protein, 5.8% fat, 13.6% fiber, 9.3% water, and 2.9% minerals).

Amaranth: (Amaranthus sp.) with 60 recognized species, makes up its own family, Amaranthaceae. The herbaceous annual grows 5 to 7 feet, with broad leaves and a showy flower head of small, red or magenta, flowers. The seed heads resemble corn tassels, but are somewhat bushier, composed of tiny (1/32"), lens shaped seeds that are a golden, creamy, tan color. Amaranth resists heat and drought; it has no major disease problems, and is among the easiest of plants to grow. Each plant is capable of producing 40,000 to 60,000 seeds that like buckwheat and quinoa, contain protein that is unusually complete for plant sources. The leaves also are a very good source of vitamins including vitamin A, vitamin B6, vitamin C, riboflavin, and folate, and dietary minerals including calcium, iron, magnesium, phosphorus, potassium, zinc, copper, and manganese. Several studies have shown that like oats, amaranth seed or oil may benefit those with hypertension and cardiovascular disease.

Oats: (Avena sativa) are an annual grass that reach 1.3 meters in height. Producing an average of 125 bushels per acre, which is 8,000-12,000 pounds per acre of biomass, oats are primarily grown for livestock feed; in fact less than 5% of the total production in this country is for human consumption (mainly as oat flour). Oat is the only cereal containing a globulin or legume-like protein, avenalins, as its major (80%) storage protein. The protein content of the hull-less oat kernel, or groat, ranges from 12–24%, the highest among cereals. Oats help conserve soil, they require relatively less chemical fertilizers, pesticides and herbicides; they reduce water contamination by agricultural chemicals, and provide nutritional benefits to both humans and animals.

 

I would like to thank Jason Bradford for sharing the following chart with me. As you can see it outlines planting dates for various crops in Willits, California. Tools like these are very useful when trying to coordinate plantings. Check and see if you can find such a graph for your location. Perhaps local farmers have generated the charts for themselves. State or Regional University Extension Programs might also be able to provide such information.