DEVELOPMENT ALREADY UNDERWAY
Woody agriculture is not merely theory. I have personally been collecting, screening and breeding hazels and chestnuts for 9 years with these goals in mind, and the work of many other researchers could also be applied to this concept. At this point in my own investigations I am convinced woody agriculture will work, based on genetic variants found and created, and on yields already achieved.
This past year one of my hazel selections, G-228-S, produced a crop which, rather conservatively extrapolated for a field planted to this one cultivar, would have yielded about 2,250 kg of kernel/hectare (nutshells excluded) (5). For comparison, soybeans, the crop most comparable, yield an average of about 2,100 kg/hectare in the US. This plant was 8 years old, grown in a situation most amenable to hand harvesting. The crop was borne in spite of extreme drought and no fertilizer in 1988, and severe drought in 1989.
Another selection, G-105-N, was cut to the ground in early spring of 1988 (ie. the wood was harvested), re-grew without fertilizer and in extreme drought, and in 1989 bore the equivalent of 764 kg of kernel/hectare. The lush re-growth of the plant demonstrates further potential for shunting photosynthate into seed production, and away from wood. This selection represents only the very crudest and earliest attempt to identify plants capable of bearing seed quickly after having the wood harvested.
The amount of kernel produced by a plant may be limited by the number of female flowers it can set. Most hazels set an average of 3-5 nuts per cluster, but I have been able to identify some individuals which typically set much more; up to 14. The potential is here to develop a hazel which bears seed almost in "cobs", rather like maize, greatly facilitating harvest.
Progress has also been made with chestnuts:
Ultra-precocious multi-species hybrids have been made which are able to flower and produce useful pollen only 3-4 months after the germination of the seed. This can tremendously accelerate breeding projects aimed at transferring genetic traits from one line to another.
Perhaps most significantly, during a recent trip to the People's Republic of China, the Hubei Academy of Agricultural Sciences requested a seminar on the subject of woody agriculture which generated great interest. At their request, I now have an agreement with scientists in the Academy to cooperate in the continuing development of chestnut for woody agriculture, and I will be sending them, next year, some of my more advanced chestnut strains for them to begin making woody agriculture type plantings in the PRC. They will also be cross-breeding my strains with their own, to further develop the crop potential, and we will continue to exchange visits, work, ideas, and genetic material.
The Chinese are now interested in developing other woody crops along these lines. While there I was introduced to a plant new to me, the "camellia oil" bush. This is a relative of tea, traditionally grown for the oil pressed from the large seed, but never developed much beyond very basic selection of slightly more productive wild bushes. In a few years of work, however, the Chinese scientists have already, through simple use of pruning, grafting, and fertilizing, increased the traditional yield of the crop by 150%. The great potential for further yield gains by cross breeding their best selections is the next avenue they are going to explore. "Camellia oil" is a perfect example of potential woody agriculture crop plants, already used traditionally, but virtually unimproved. Such plants exist in every region of the world, awaiting our attention.
SUGGESTED CRITERIA FOR NEW CROP SPECIES
In order to be most effective, the development of woody agriculture should proceed simultaneously in many parts of the world, with many different species of crop plants. It may be helpful to point out some factors which will increase the success of new woody crops.
The crop product must be a fruit or seed which can be easily preserved and stored in bulk, in common storage facilities, like those for cereals and pulses. Perishable and fragile fruits are not desirable.
The plant should be one which re-grows rapidly and easily after it is cut down.
Species which naturally grow in dense stands, or thickets, will probably prove more disease resistant when planted in uniform fields than those which naturally grow widely separated from other trees or bushes of the same species. Thicket forming species may also be better adapted to growing well in crowded, competitive conditions.
In order to develop a new crop species, it will be necessary to find or breed strains of the plant which produce seed at a very young age. I have found and bred hybrid chestnuts which produce pollen only 4 months after germination of the seed; similar precocity can be achieved in most species, but finding the most naturally precocious material to start with will greatly speed the process.
It would be best to select potential crop plants from among large plant families. In this way access to much larger genetic variability, through inter-species hybrids, can be made available to breeders. Choosing a plant with no close relatives will limit the potential of the crop.
Could woody agriculture be part of a planned response to the possibility of global warming? Certainly, but it is a practice with a very long lead time. The following are my own optimistic guesses about how long it would take for extensive plantings of woody crops to make a significant impact on global CO2 concentrations, provided an organized effort were mounted to make this strategy work.
|1. Time to identify regionally useful crop candidates and create working research plantings.||5 years|
|2. Time to select first generation crop clones, and develop large scale production techniques.||10 years|
|3. Time to make substantial first plantings and bring them into production (1 X 10^6 hectares).||6 years|
|4. Time for significantly large plantings to be made and profitably managed||10 years (subsidized) 30 years (unsubsidized)|
|5. Unforeseen circumstances.||10 years|
|Total................................................||40 to 60 years.|
Inevitably, this seems like an impossibly long time. However, when considering the slowness with which the globe reacts to any changes, this is actually quite a reasonable response to consider.
A significant factor on the side of using woody agriculture as a response to global warming is the fact that the other environmental benefits of the concept are so large that it is worth undertaking for those considerations alone, regardless of whether one believes in the inevitability of global warming. It should not be nearly as difficult to "sell" as cutting back on "development" and economic growth. It might actually be an important factor in making "sustainable development" a reality, rather than a hope.
Since it is the goal of this meeting to produce action, rather than mere discussion, I include the following requirements if woody agriculture is to be part of the world response to the climate change threat.
1. Some organization needs to take responsibility for spreading the concept, and educating regional scientists of the possibilities and benefits. I have already stimulated a research and planting program in China, but similar programs need to be initiated around the globe.
2. Number one requires money. It must be found if progress is to begin.
3. There are excellent agricultural research organizations, both public and private, around the world. If they can be genuinely interested in pursuing woody agriculture, an enormous amount of work can quickly be accomplished.
4. While waiting for numbers 1-3 to be accomplished, interested workers can begin now the task of identifying and planting working collections of woody plants potentially adaptable for intensive cultivation in their own regions.
Woody agriculture, the intensive production of staple foodstuffs from woody plants, has real potential to significantly offset the buildup of atmospheric CO2. Present estimates of the annual increase in atmospheric carbon are around 3 gigatons; if woody plants could be substituted for the traditional annual crops now being grown on 1/4 of world crop lands, they would fix an additional 5 gigatons of carbon per year, with no decrease in food production. In addition, the fact that woody crops would not require plowing, planting, or cultivating (after initial establishment), means that when substituted for mechanized crops, they would not require between 4.77 X 10^10 to 3.38 X 10^10 grams carbon/10^6 hectares planted in diesel fuel (fossil carbon) currently expended for those operations.
Yields of food from woody plants, measured on an experimental basis, already equal, and may surpass, yields from soybeans. In addition to the food produced, fuelwood may also be harvested from the same plantings, alleviating pressure on remaining forests. 4thave NW 228
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1. Rutter, P.A. 1989. Reducing Earth's "greenhouse" CO2 through shifting staples production to woody plants. Proceedings of the Second North American Conference on Preparing for Climate Change, Washington DC, December 6-8, 1988. The Climate Institute.
2. Fuller, Earl; Bill Lazarus and Dave Nordquist. 1989. Minnesota farm machinery economic cost estimates for 1989. AG-FO-2308. Minnesota Extension Service, University of Minnesota. St. Paul, Minnesota.
3. Moncrief, J.F, J.A. True, & M.L. Mellema. 1987. Tillage, Energy and Yields for Corn and Soybeans. AG-BU-3290. Minnesota Extension Service, University of Minnesota. St. Paul, Minnesota.
4. Phillippine Council for Agriculture and Resources Research; and (US) National Academy of Sciences. 1977. Leucaena; promising forage and tree crop for the tropics. 115 pgs. National Academy of Sciences, Washington, DC.
5. Rutter, P.A. 1987. Badgersett Research Farm- Plantings, Projects, and Goals. Annual Report of the Northern Nut Growers Assoc. pp.173-186