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Large scale permaculture
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"David Hare-Scott" wrote: "len gardener" wrote in message ... g'day david, there is this place here in south aus' http://foodforest.com.au/ don't know that it fits your scale or not they are growing edible stuff using p/c principals, but it is still marginal land that is being used for less the habitat which it would serve the community better as. permaculture is more a mind set of ideas to look after the planet better, once commercialism comes into it then profit will over ride. I agree about the mindset. But we are embedded in a largely free enterprise society in which you have to be commercially viable to keep going. Mollison's philosophy is such that he would remake much of society, its values and motives not merely how we get our food. Although he does give a nod to "legality, people, culture, trade and commerce" as a component in creating a design. So perhaps he does accept that commerce and making a dollar is not altogether evil. The question is how do you do it in a society whose agriculture is based on permaculture? Energy is costing more. Local food tastes better than trucked in food. Diversified farmers cut out the middle man and get top dollar (for what it is worth these days) for their crops. It looks like the market could work to the consumers benefit. Unfortunately not all crop land is near its' consumers, so something needs to be done about the expensive bottlenecks i.e. Cargill, Archer Daniel Midlands, et al. and some kind of social support and remediation for growers of mono-cultures. I know of small scale operations where on a few acres a family is growing enough to mainly feed themselves and sell some to make a dollar to buy what they cannot grow. This makes that family very happy, they have the ability to live in the way that they see it is proper to live. However Mollison puts forward the idea that permaculture could/should replace broadacre farming altogether. This leads me to a problem. I cannot see how every family can have a few acres nor the will/ability to farm it. I cannot see how we can get away from at least some specialists who use their skill to get food from the land efficiently on a scale that permits the feeding of the non-farmers who produce other things. In the long run the choice is to do it sustainably or to starve when we have mined out the soil. So what replaces broadacre? The Cuban Model The Revolution Will Not Be Microwaved by Sandor Katz p. 28 - 30 Local and seasonal eating usually requires that we adjust our expectations. Some foods we are used to eating on a daily basis may simply not be possible in this scheme. For instance, unless you live in Florida, you might have to let go of that morning glass of orange juice. But other foods, no less delicious or nutritious (in fact generally far more so), will replace them. We can learn to love what grows abundantly and easily around us and reorient our tastes and our habits. Another completely different take on the idea of a local food challenge a "land fast," a period of eating only what can be harvested in the immediate vicinity, in the gardens and the woods. In certain seasons, one could be very satisfied. Relatively few people have voluntarily chosen to make the switch to exclusively local foods. But in some cases circumstances have resulted in the abrupt disappearance of global trade, and it has been demonstrated that people can survive and restore food sovereignty. Take, for example, Cuba. Until 1989 Cuba's major trading partners were the Soviet nations of Eastern Europe. Cuba exported sugar and imported most other foods, as well as fuel, machinery, and chemicals. In 1989 about three times as much Cuban land was planted in sugar cane than was planted in all other food crops combined. Fifty-seven percent of the calories in the Cuban diet were imported. But the abrupt disintegration of the Soviet-allied governments and the Soviet Union itself resulted in the sudden loss of these trading partners. The loss of its trade partners meant a loss of two-thirds of Cuba's food supply, as well as the fuel, machinery, and chemicals upon which its agricultural system depended. Compounding the shortages was a tightening of the U.S. economic blockade of Cuba in the early 1990s. The food shortage was so acute that diseases of malnutrition became widespread. Lacking the "inputs" (such as chemicals, fuel, and hybrid seeds) required for industrial-style monoculture, Cuba was forced to transform its farming system. Food production was decentralized, and farmers in each region were encouraged to diversify rather than specialize. Urban, family, and community gardening, which had always been features of Cuban life, were officially encouraged, and a program ot public education and model farms was undertaken to spread knowledge about biological farming methods. The Ministry of Agriculture even replaced its front lawn with vegetable gardens. By 1999, Cuba had become a nation of food producers. Urban gardens alone produced more than eight hundred thousand tons of food, mostly vegetables. There is no way to compare this sector to pre-1989 levels, because until then this sector was considered insignificant[ and not counted. However, this remarkable statistic shows that cities can produce food, though not in the style of acres upon acres of grain fields; instead, intensive cultivation of yards and parks and rooftops can ensure a steady supply of fresh produce to urbanites (for more on urban gardening, see chapter 3). The prospect of a crisis is obviously not the only compelling reason to revive local food production. There are many benefits of local food, starting with flavor, continuing through nutrition, and definitely including community economic stability. But it's good for us who live in a culture of constant convenience consumerism to be reminded that the time-honored methods of producing food can still feed people perfectly adequately. For most people in most places throughout time, the food available has been organic and local. Organic was all there was until the mid-twentieth century, and anything beyond local, to the extent that it was available at all, was an expensive luxury, out of daily reach for average people. Abundant globalized food may not always be available to us either. It is easy for me to imagine the United States, or the whole world, in suddenly different economic circumstances, with an abrupt halt to all international trade, as Cuba faced in 1989, that forces a transition to greater dependence on community-based food production. The skills and practice of food production are important to revive and to prevent from disappearing. The following is a little messy because I haven't finished cleaning it up but perennial crops that can replace annual crop are being developed. Scientific American, August, 2007 For many of us in affluent regions, our hath-room scales indicate that get more than enough to eat, which may lead some to believe that it is easy, perhaps too easy, for farmers to grow our food. On the contrary, modern agriculture requires vast areas of land, along with regular infusions of water, energy and chemicals. Noting these resource demands, the 2005 United Nations-sponsored Millennium Ecosystem Assessment suggested that agriculture may be the ³largest threat to biodiversity and ecosystem function of any single human activity." Today most of humanity's food comes directly or indirectly (as animal feed) from cereal grains, legumes and oilseed crops. These staples are appealing to producers and consumers because they are easy to transport and store, relatively imperishable, and fairly high in protein and calories. As a result such crops occupy about 80 percent of global agricultural land. But they are all annual plants, must be grown anew from seeds every year, typically using resource-intensive cultivation methods. More troubling, the environmental degradation caused by agriculture will likely worsen as the hungry human population grows to eight billion or 10 billion in the coming decades. That is why a number of plant breeders, agronomists and ecologists are working to develop grain-cropping systems that will function much more like the natural ecosystems displaced by agriculture. The key to our collective success is transforming the major grain crops into perennials, which can live for many years. The idea, actually decades old, may take decades more to realize, but significant advances in plant-breeding science are bringing this goal within sight at last. Roots of the Problem Most of the farmers, inventors and scientists who have walked farm fields imagining how to overcome difficulties in cultivation probably saw agriculture through the lens or' its contemporary successes and failures. But in the 1970s Kansas plant geneticist Wes Jackson took a 10,00 year step into the past to agriculture with the natural systems that preceded it. Before humans boosted the abundance of annuals through domestication and Farming, mixtures of perennial plains dominated nearly all the planet's landscapes-as they still do in uncultivated areas today. More than 85 percent of North America's native plant species, for example, are perennials. Jackson observed that the perennial grasses and flowers of Kansas'S tall-grass prairirs were highly productive year after year, even as they built and maintained rich soils.They needed no fertilizers, pesticides or herbicides to thrive while fending off pests and disease. Water running off or through the prairie soils was clear, and wildlife was abundant. In contrast, Jackson saw that nearby fields of annual crops, such as maize, sorgum, wheat, sunflowers and soybeans, requent and expensive care to remain productive. Because annuals have relatively shallow roots-most of which occur in the top 0.3 meter of soil-and live only until harvest, many farmed areas had problems with soil erosion, depletion of soil fertility or water contamination. Moreover, the eerily quiet farm fields were mostly barren of wildlife. In short, sustaining annual monocultures in so many places was the problem, and the solution lay beneath Jackson's boots: hardy and diverse perennial root systems. ---------- Key Facts o Modern intensive land use quashes natural biodiversity and ecosystems. Meanwhile the population will balloon to between eight billion and 10 billion in the coming decades, requiring that more acres be cultivated. o Replacing single-season crops with perennials would create large root systems capable of preserving the soil and would aillow cultivation in areas currently considered marginal. o The challenge is monumental, but if plant scientists succeed, the achievement would rival humanity's original domestication of food crops over the past 10 millennia-and be just as revolutionary. -The Editors --------- If annual crops are problematic and natural ecosystems offer advantages, why do none ofour important grain crops have perennial roots? The answer lies in the origins of farming. When our Neolithic ancestors started harvesting seed-bearing plants near their settlements, several factors probably determined why they favored annuals. The earliest annuals to be domesticated, emmer wheat and wild barley, did have appealingly large seeds. And to ensure a reliable harvest every year, the first farmers would have replanted some of the seeds they collected. The characteristics of wild plants can vary greatly, however, so the seeds of plants with the most desirable traits, such as high yield, easy threshing and resistance to shattering, would have been favored. Thus, active cultivation and the unwitting application of evolutionary selection pressure quickly rcsuhed in domesticated annual plants with more appealing qualities than their wild annual relatives. Although some perennial plants might also have had good-size seeds, they did not need to be replanted and so would not have been subjected to-or benefited from-the same selection process. Roots as Solution Today the traits of perennials are also becoming better appreciated. With their roots commonly exceeding depths of two meters, perennial plant communities are critical regulators of ecosystem functions, such as water management and carbon and nitrogen cycling. Although they do have to invest energy in maintaining enough underground tissue to survive the winter, perennial roots spring info action deep within the soil whenever temperatures are warm enough and nutrients and water are available. Their constant state of preparedness allows them to be highly productive yet resiliant in the face of environmental stresss. environ i nental stresses. In a century-long study of factors affecting soil erosion, timothy grass, a perennial hay crop, proved roughly 54 times more effective in maintaining topsoil than annual crops did. Scientists have also documented a five fold reduction in water loss and a 35-fold reduction in nitrate loss from soil planted with alfalfa and mixed perennial grasses as compared with soil under corn and soybeans. Greater root depths and longer growing seasons also let perennials boost their sequestration of carbon, the main ingredient of soil organic matter, by 50 percent or more as compared with annually cropped fields. Because they do no! need to be replanted every year, perennials require fewer passes of farm machinery and fewer inputs of pesticides and fertilizers as well, which reduces fossil-fuel use. The plants thus lower the amount ol' carbon dioxide in the air while improving the soil's fertility. Herbicide costs for annual crop production may be four to 8.5 times the herbicide costs for perennial crop prodiiclion, so fewer inputs in perennial systems mean lower cash expenditures for the farmer. Wildlife also benefits: bird populations, for instance, have been shown to be seven times more dense in perennial crop fields than in annual crop fields. Perhaps most important for a hungry world, perennials are far more capable of sustainable cultivation on marginal lands, which already have poor soil quality or which would be quickly depleted by a few years of intensive annual cropping. For all these reasons, plant breeders in the U.S. and elsewhere have initiated research and breeding programs over the past five years to develop wheat, sorghum, sunflower, intermediate wheatgrass and other species as perennial grain crops. When compared with research devoted to annual crops, perennial grain development is still in the toddler stage . Taking advantage ofthe significant advances in plant breeding over the past two or three decades, however, will make the large-scale development of high-yield perennial grain crops feasible within the next 25 to 50 years. Perennial crop developers are employing essentially the same two methods as those used by many other agricultural scientists: direct domestication of wild plants and hybridization of existing annual crop plants with their wild relatives. These techniques are potentially complementary, but each presents a distinct set of challenges and nclvnnrngcs as well. Assisted Evolution Direct domestication of wild perennials is the more straighcforward approach to creating perennial crops. Relying on time-tested methods of observation and selection of superior individual plants, breeders seek to increase the frequency of genes for desirable traits, such as easy separation of seed from husk, a nonshattering seed, large seed size, synchronous maturity, palatability, strong stems and high seed yield. Many existing crops, such as corn and sunflowers, lent themselves readily to domestication in this manner. Native Americans, for example, turned wild sunflowers with small heads and seeds into the familiar large-headed and largeseeded sun flower [see box on page 88]. Active perennial grain domestication programs are currently focused on intermediate wheatgrass (Thinopyrum intermedium), Maximilian sunflower (Helianthus maximiliani), Illinois bundleflower (Desmanthus illinoensis) and flax (a perennial species of the Linum genus). Of these, the domestication of intermediate wheatgrass, a perennial relative of wheat, is perhaps in the most advanced stages. To use an existing annual crop plant in creating a perennial, wide hybridization-a forced mating of two different plant species-can bring together the best qualities of the domesticated annual and its wild perennial relative. Domesticated crops already possess desirable Attributes, such as high yield, whereas their wild relatives can contribute genetic variations for traits such as the perennial habit itself as well as resistance to pests and disease. Of the 13 most widely grown grain and oil-seed crops, 10 are capable of hybridization with perennial relatives, according to plant breeder T. Stan Cox of the Land Institute, a Kansas non-profit that Jackson co- founded to pursue sustainable agriculture. A handful of breeding programs across the U.S. are currently pursuing such interspecific (between species) and intergeneric (between genera) hybrids to develop perennial wheat, sorghum, corn, flax and oilseed sunflower. For more than a decade, UniversityofManitoba researchers have studied resource use in perennial systems, and now a number of Canadian institutions have started on the long road to developing perennial grain programs as well. The University of Western Australia has already established a perennial wheat program as part of that country's Cooperative Research Center for Future Farm Industries. In addition, scientists at the Food Crops Research Institute in Kunming, China, are continuing, work initiated by the International Rice Research Institute in the 199Os to develop perennial upland ncr rice hybrides. At the Land Institute, breeders are working both on domesticating perennial wheatgrass and on crossing assorted perennial wheatgrass species (in particular, Th. intermedium, Th. ponticum and Th. elongatum) with .annual wheats. At present, 1,500 such hybrids and thousands of their progeny are being screened for perennial traits. The process of creating these hybrids is ilself labor-intensive and time- consummg. Once breeders identify candidates for hyhridization, they must manage gene exchanges between disparate species by manipulating pollen to make a large number of crosses between plants, selecting the progeny with desirable traits, and repeating this cycle of crossing and selection again and again. Hybridization nonetheless is a potentially faster means to create a perennial crop plant than domestication, although more technologyis often required to overcome genetic incompatiibilitiess between the parent plants. A seed produced by crossing two distantly related species, for example, will often abort before it is fully developed. Such a specimen can be "rescued" as an embryo by growing it on artificial medium until it produces a few roots and leaves, then transferirng the seedling to soil, where it can grow like any other plant. When it reaches the reproductive stage, however, the hybrid's genetic anomalies frequently manifest as an inability to reproduce seed. ------------- 10 CROPS Annual cereal grains, food legumes and oilseed plants claimed 80 percent of global harvested cropland in 2004. The top three grains covered more than half that area. CROP LAND % 1. Wheat 17.8 2. Rice 12.5 3. Maize 12.2 4. Soybeans 7.6 5. Barley 4.7 6. Sorghum 3.5 7. Cottonseed 2.9 8. Dry beans 2.9 9. Millet 2.8 10. Rapeseed/mustaic! 2.2 ------------- A partially or fullv sterile hybrid generally results from incompatible parental chromosomes within its cells. To produce eggs or pollen, the hybrid's chromosomes must line up during meiosis (the process by which sex cells halve their chromosomes in preparation for joining with another gamete) and exchange genetic information with one another. If the chromosomes cannot find counterparts because each parent's version is too different, or if they differ in number, the meiosis line dance is disrupted. This problem can be over come in a few ways. Because sterile hybrids are usually unable to produce male gametes but are partially fertile with feni a 1c gametes, pollinating them with one of. the original parents, known as backcrossi ing, can restore fertility. Doubling the num1 ber of chromosomes, either spontaneously or by adding chemicals such as colchicine, is another strategy. Although each method al- lows for chromosome' pairing, subsequent chromosome eliminations in each successive generation often happen in perennial wheat hybrids, particularly to chromosomes in her if cd from the perennial parent. Because of the challenging gene pools created by wide hybridization, when fertile perennial 'hybrids are identified, biotechnology techniques that can reveal which parent contributed parts of the progeny's genome arc useful. One of these, genomic in situ hybridization, for example, distinguishes the perennial parent's chromosomes from those of the annual parent by color fluorescence and also detects chromosome anomalies, such as structural rearrangement between unrelated chromosomes (see bottom illustration on next page). Such analytical tools can help speed up a breeding program once breeders discover desirable and undesirable chromosome combinations, without compromising the potential for using perennial grains in organic agriculture, where genetically engineered crops are not allowed. Another valuable method for speeding and improving traditional plant breeding is known as marker-assisted selection. DNA sequences associated with specific traits serve as markers that allow breeders to screen crosses as seedlings for desired attributes without having to wait until the plants grow to maturity [see "Back to the Future of Cereals," by Stephen A. Goff and John M. Salmeron; SCIENTIFIC AMERICAN, August 2004]. At present, no markers specific to perennial plant breeding have been established, although it is only a matter of time. Scientists at Washington State University, for example, have already determined that chromosome 4E in Thelongatum wheatgrass is necessary for the important perennial trait of regrowth following asexual reproduction cycle. Narrowing down the region on 4E to the gene or gene's that produce the trait would reveal relevant DNA markers. that will save breeders a year of growing time in assessing hybrids. Perennialism is nonetheless an intricate life path that goes well beyond a single trait, let alone a single gene. Because of this complexity, trans- genic modification (insertion of foreign DNA) is unlikely to be useful in developing perennial grains, at least initially. Down the road, trans- genic technology may have a role in refining sim- ple inherited traits. For example, if a domesticat- ed perennial wheatgrass is successfully devel- oped but still lacks the right combination of gluten-protein genes necessary for making good- quality bread, gluten genes from annual wheat could be inserted into the perennial plant. Trade-offs and Payoffs Although perennial crops, such as alfalfa and sugarcane, already exist around the world, none has seed yields comparable to those of annual grain crops. At first glance, the idea that plants can simultaneously direct resources to building and maintaining perennial root systems and also produce ample yields of edible grains may seem counterintuitive. Carbon, which is cap- tured through photosynthesis, is the plant's main building block and must be allocated among its various parts. Critics of the idea that perennials could have high seed yield often focus on such physiologi- cal trade-offs, assuming that the amount of car- bon available to a plant is fixed and therefore that carbon allocated to seeds always comes at the expense of perennating structures, such as roofs and rhizomes. Doubters also often over- look the fact that the life. spans of perennial plants exist along a spectrum. Some perennial prairie plants may persist for 50 to 100 years, whereas others live for only a few years. Fortu- nately for breeders, plants are relatively flexible organisms: responsive to selection pressures, they are able to change the size of their total car- bon "pies" depending on environmental condi- tions and to change the allocation of pie slices. A hypothetical wild perennial species might live 20 years in its highly competitive natural' environment and produce only small amounts of seed in any year. Its carbon pie is small, with much of it going toward fending off pests and disease, competing for a few resources and per- sisting in variable conditions. When breeders take the wild specimen out of its resource- strapped natural setting and place it into a man- aged environment, its total carbon pie suddenly grows, resulting in a bigger plant. Over time, breeders can also change the size of the carbon slices within that larger pie. Mod- ern Green Revolution grain breeding, when combined with increased use of fertilizers, more than doubled the yield of many annual grain crops, and those increases were achieved in plants that did not have perennating structures to sacrifice. Breeders attained a portion of those impressive yield expansions in annual crops by selecting for plants that produced less stem and leaf mass, thereby reallocating that carbon to seed production. Yields can be similarly increased without eliminating the organs and structures required for overwintering in perennial grain crops. In fact, many perennials, which are larger overall than annuals, offer more potential for breeders to reallocate vegetative growth to seed produc- tion. Furthermore, for a perennial grain crop to be successful in meeting human needs, it might need to live for only five or 10 years. In other words, the wild perennial is unnec- essarily "overbuilt" for a managed agricultural setting. Much of the carbon allocated to the plant's survival mechanisms, such as those al- lowing it to survive infrequent droughts, could be reallocated to seed production. Greener Farms Thus, we can begin to imagine a day 50 years from now when farmers around the world are ..walking through their fields of perennial grain crops. These plots would function much like the Kansas prairies walked by Wes Jackson, while also producing food. Belowground, different types of perennial roots-some resembling the long taproots of alfalfa and others more like the thick, fibrous tangle of wheatgrass roots- would coexist, making use of different soil lay- ers. Crops with alternative seasonal growth habits could be cultivated together to extend the overall growing season. Fewer inputs and great- er biodiversity would in turn benefit the envi- ronment and the farmer's bottom line. Global conditions-agricultural, ecological, economic and political-are changing rapidly in ways that could promote efforts to create pe- rennial crops. For instance, as pressure mounts on the U.S. and Europe to cut or eliminate farm subsidies, which primarily support annual crop- ping systems, more funds could be made avail- able for perennials research. And as pnergy pric- es soar and the costs of environmental degrada- tion are increasingly appreciated, budgeting public money for long-term projects that will re- duce resource consumption and land depletion will become more politically popular. Because the long timeline for release of pe- rennial grain crops discourages private-sector investment at this point, large-scale government or philanthropic funding is needed to build up a critical mass of scientists and research pro- grams. Although commercial companies may not profit as much by selling fertilizers and pes- ticides to farmers producing perennial grains, they, too, will most likely adapt to these new crops with new products and services. Annual grain production will undoubtedly still be important 50 years from now-some crops, such as soybeans, will probably be diffi- cult to perennialize, and perennials will not completely eliminate problems such as disease, weeds and soil fertility losses. Deep roots, how- ever, mean resilience. Establishing the roots of agriculture based on perennial crops now will give future farmers more choices in what they can grow and where, while sustainably produc- ing food for the burgeoning world population that is depending on.them. * BREEDING HYBRID plants can require rescuing an embryo from the ovary (/eft). A researcher bags annual sor- ghum heads to collect pollen, with tall perennial sorghum in the background {right}. Perennial Grain Crops: An Agri- cultural Revolution. Edited by Jerry D. Glover and William Wilhelm. Special issue of Renewable Agricul- ture and Food Systems, Vol. 20, No. 1 March 2005. Wes Jackson (35 Who Made a Difference). Craig Canine in special anniversary issue oiSmithson ian, Vol. 36, No. 8, pages 81-82; November 2005. Prospects for Developing Peren nial Grain Crops. Thomas S. Cox, Jerry D. Glover, David L. Van Tassel, Cindy M. Cox and Lee D. DeHaan in BioScience, Vol. 56, No. 8, pages 64? 659;August 2006. Sustainable Development of the Agricultural Bio-Economy. Nich las Jordan et al. in Science, Vol. 316, pages 1570-1571;June 15,2007. The Land Institute: (THE AUTHORS] ibii; :.; ^ r i; r. an agroecolo- gist and director of graduate research at the Land Institute in Salina, Kan., a nonprofit organiza- tion devoted to education and research in sustainable agriculture. Cindy M. Cox is a plant patholo- gist and geneticist in the insti- tute's plant-breeding program. John P. Reganold, who is Regent;, Professor of Soil Science at Wash- ington State University at Pullman, specializes in sustainable agricul- ture and last wrote for Scientific American on that subject in the June 1990 issue. --------- I hope you find something useful in the above. David -- Billy Impeach Pelosi, Bush & Cheney to the Hague http://angryarab.blogspot.com/ http://rachelcorriefoundation.org/ |
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