The following document is adapted from an old grant proposal- and thus may have a few references to funding that we haven't managed to expunge, and states a few "future goals" which are now accomplished realities. It nontheless may be the most straightforward statement of the practices and benefits of using woody plants for agriculture.
Introduction to "Woody Agriculture" - 1991
"Woody agriculture" refers to the intensive production of agricultural staple commodities from highly domesticated woody perennial plants. It differs from "agroforestry" in that no annual crops are grown, and thus little or no tillage is performed. Permanent stands of the woody crop are established, seeds harvested annually, and once every 5-10 years the wood is harvested for biomass; whereupon the plants regenerate from the roots and resume production of the food crop one year after coppicing.
The concept has been developed at Badgersett Research Farm during the past 20 years. Data on yields of specific crops indicate commercialization is now possible. No commercial scale woody agriculture planting yet exists. This is the next step necessary to make the tremendous environmental advantages of this cropping system available to farmers.
Advantages include:
1) No tillage following establishment, hence vastly decreased erosion and energy requirements.
2) Woody plants are intrinsically more effective at capturing light than annual plants, and can capture 3 times more solar energy per year, which can be used by the plant to make seed or wood.
3) This photosynthetic efficiency means agricultural woody plants, if used on a very large scale, could reverse present global increases in CO2, and possibly global warming.
4) Diversification of agriculture.
5) Drought resistance.
6) Flood tolerance.
7) Greatly increased biodiversity of fields.
8) From the outset, plants chosen for development have been designed to produce crops for existing markets, using technology that can and will be adopted by mainstream agriculture; this will make the benefits of the system available to the largest number of farmers, greatly increasing potential beneficial impact.
The Concept of Woody Agriculture
Use of the phrase "woody agriculture" is very recent, and unfamiliar to most. The capsule description given above is succinct, but may leave the reader with some questions. Is it really possible to grow staple food commodities on woody plants? Could woody plants be as productive as annuals? If so, why isn't it done now?
Woody plants are seldom considered for intensive development as producers of staple foodstuffs. Historically, the only trees that have contributed in a major fashion to world food supplies have been the date, oil, and coconut palms, and possibly the olive. Most trees are commonly perceived as rather unproductive, slow growing, or unreliable, and seem unattractive for serious food production. On serious examination of the dynamics of these plants however, it appears likely that trees and other woody plants have been greatly underestimated in regard to their potential for true domestication. There appear to be several unstated and unexamined assumptions agricultural researchers commonly make about woody plants, which may in fact not hold true.
Assumption 1: Woody plants produce seed crops too erratically to be relied on for basic food production. This assumption has the invulnerability of the half-truth: wild trees commonly produce seed crops erratically. However, the evidence is very clear that this is not because consistent production is impossible, but because it is ecologically the better course for a wild tree. Experience with many fruit trees shows that consistent bearing has a large genetic component. Chestnut, in particular, belies this assumption, in that even wild stands produce good seed crops with relatively minor fluctuations.
Assumption 2: It is not possible to produce wood and food (seed) simultaneously. This assumption is again based primarily on wild or semi-domesticated trees. Research on Short Rotation Intensive Cropping (SRIC), however, has demonstrated that strains of woody plants specifically selected for maximum fiber production achieve an annual carbon fixation rate approximately 3 times that of one-crop maize. This means there is 3 times as much energy flowing through the plant. There is no barrier to allocating this energy differently through breeding or cultural technique, so that, for example, 1/3 goes to harvestable seed, 1/3 to wood, and 1/3 to energy storage for the next season. Again, chestnuts provide a crop pre-adapted to these requirements: wild chestnuts produce nut crops annually, and also produce wood 30-50% faster than oaks growing in the same area.
Assumption 3: Woody plants take too long to breed. Badgersett Research Farm has bred 2 different lines of hybrid chestnuts which produce flowers within 2 months of seedling germination. This is possible with other species as well.
Ten years of research with hazelnuts and chestnuts at Badgersett Research Farm lead us to strongly believe that the potential for developing many kinds of woody plants for food production is much greater than commonly believed.
We are now ready to proceed with the development of these two crops on a commercial scale. As envisioned, plantings will not resemble traditional orchards, but will consist of closely spaced bushes, from 3' to 8' tall, with little or no visible space between their branches. Thus nearly all sunlight falling on the field can be captured, and converted to crop.
Hazelnuts are a commodity in international trade, approximately 70% of the world crop being produced by Turkey. The nuts are about 70% oil, most of which is monounsaturated, and 20% protein. Most of the crop is used in chocolate confections, and a smaller portion is consumed in roasted nut mixes. Potential uses of the crop extend far beyond present traditions. Some hazelnut oil is marketed for human consumption, and brings extremely high prices for its lightness and flavor. The oil market presents a prime possibility for expansion. In fact, hazelnuts appear to be an excellent basic raw material, comparable to soybeans.
Chestnuts likewise have a strong existing market, some 14 million pounds being consumed in the USA annually, nearly all of it imported from Italy. Consumption in Europe and the Orient is very much greater (see supporting materials). Chestnuts more closely resemble wheat or maize than soybeans, in that they have a low oil content, and are high in complex starches. Chestnut flour has been used to make baked goods in Europe and the Orient for millenia, but production from the wild and near-wild plantings has never equalled the demand.
Economically Driven Change
A key point to remember is that our goal is to provide farmers with crops and agricultural practices which they will want to adopt for economic reasons. If a particular crop or practice is "good for the environment", but brings no economic benefits to the farmers, relatively few farmers will change their habits and equipment.
While farmers are constantly assumed to be conservative about changing their crops, history clearly records that they respond to market forces: witness the fact that in 1930, for all practical purposes, there was no one growing soybeans in the New World. Because soybeans proved profitable, however, many farmers have learned to plant and grow them, and millions of acres of soybeans are planted each year, throughout North and South America.
The woody crops we are developing have the potential to be more profitable than soybeans, particularly during the early years. This is because strong markets for the raw nuts already exist- we do not have to create demand for an unknown crop. This presents the real likelihood that large plantings will be made, extending the environmental benefits of the woody agriculture practices to large areas. With foresight, as the plantings expand and traditional markets are saturated, new products and markets can be developed, exactly as was done for soybeans; allowing plantings to expand much further.
In the event that this scenario of a large scale, economically driven shift to an ecologically sounder form of agriculture can be accomplished, some of the benefits will be those outlined below.
Issues And Problems Addressed, And Potential Impacts
The possible benefits outlined here are unusually large, and affect many different issues. In the case of woody agriculture, however, the benefits really could be this extensive.
Sustainable Agriculture
The increasing fragility of the world's ecosystems and agricultural production systems is widely acknowledged. Unacceptably high soil erosion and accompanying degradation of aquifers and aquatic ecosystems, agricultural fertilizer and chemical runoff, excessive energy (fossil fuel) requirements for crop production, are all critical global problems that are in part the direct result of the universal reliance upon annual plants for the world's food supply.
Because traditional crops need to be planted every year, the soil must be tilled several times annually. Soil is thus bare and exposed to wind and water erosion throughout the time of the early growth of these crops. Even when mature, fields are susceptible to erosion because of the naked soil between plants. After harvest and through the dormant season the soil is again exposed and vulnerable. The need for tillage, cultivation, fertilizer, and pesticides means many passes through a field with heavy, energy intensive equipment.
In woody agriculture, crops would be planted only once in a lifetime. The use of woody perennials for agricultural staple commodities production would result in little or no use of tillage, and the presence of a permanent cover, during both the growing and the dormant seasons. Not only would this lead to a vastly lower rate of soil loss, and less runoff into water supplies and aquatic environments, but to a reduced need for the fossil fuels consumed in plowing and tilling. In addition, use of pesticides needed for the establishment of annual plants could be sharply reduced. A further important benefit would be the reduction of soil compaction, since far fewer trips through the fields with heavy equipment would be required.
Stability of the World Food Supply
Presently the vast majority of world food is produced from a remarkably low number of crops, and often from a very few varieties of those crops. This leaves mankind always at some risk, since it is always possible (indeed likely) that new diseases will develop, or unfavorable weather will occur, resulting in massive food shortages. Painful historical examples include the potato famine, the droughts in the Sahel of Africa, and nearer home the wet spring of 1989, when farmers in much of the US corn belt were unable to plant their crops on time because of water saturated fields, resulting in greatly reduced yields.
Woody agriculture can contribute greatly to the stability of the world food supply in several ways. Simply introducing new staples into common use would be a great benefit; the more species are involved in food production, the more easily the food system can withstand momentary failures of any particular crop. A key goal of our work, in fact, is to demonstrate the feasibility of using woody plants for intensive food production, and directly stimulate similar domestication efforts in localities around the world, using as many different native species as possible; we already have a cooperative research program with the Peoples Republic of China.
In a completely different effect, woody agriculture can stabilize agricultural production because the deep permanent root systems of the crop plants are very insensitive to mild droughts or short term flooding- both of which can cause drastic or total crop losses in annual species. This same deep root system will also much more effectively capture any necessary fertilizers; resulting both in reduced cost to the farmer, and greatly reduced (or no) fertilizer runoff.
Global Warming
The "greenhouse effect" is still under some debate, but it is becoming very clear that even small amounts of global warming may have severe negative effects on global climate. Woody agriculture has an unparalleled potential to reduce the buildup of CO2, the most important of the "greenhouse gases". Calculations indicate that theoretically, if 1/4 of world crop lands could be converted to woody crops, this action alone could not only halt but actually reverse the increase in atmospheric CO2. No other action contemplated by any of the agencies dealing with global warming has such potential (see supporting materials).
The potential use of trees (and other woody plants) to sequester carbon and thus ameliorate the projected greenhouse effect is severely limited by the need to use the world's most productive lands for food production. This results in several negatives: land area available for afforestation is limited, and only land unsuitable for agriculture is considered; ie. steep, shallow soiled, unstable, inaccessible, or infertile, or perhaps all of these.
Once the feasibility of woody agriculture is demonstrated, farmers can (and will, based on clear historical precedent), adopt these woody crops systems on their best land, thus making the 1.5 x 109 hectares of the world's crop lands available to the carbon sequestration power of woody plants.
Global Deforestation
A major factor contributing to global deforestation is the critical shortage in the developing countries of fuel wood for cooking. Woody agriculture, because of the much greater photosynthetic potential, would allow farmers to grow their own fuel wood on the same ground they now use for food crops, without loss of food production. Large scale plantings will produce far more fuel wood than the farmer can consume, and the fuel wood will be another profitable crop. This potential for greatly increased fuel wood production could have considerable impact on deforestation, to the extent that pressure on existing forests is relieved.
Yet another possible effect here is that fields derived from cleared tropical rainforest are notorious in their rapid degradation when planted to annual crops, due to erosion and nutrient loss. Such degraded fields may reasonably be expected to support woody crops better than they can annuals, due to the deeper root systems and decreased tillage requirements. This could be another factor operating to remove pressure to cut remaining forests, if farmers can indeed sustain cropping potentials on lands already cleared.
Biomass Energy Production
In the developed world, large scale mechanized woody agriculture would result in the annual production of great quantities of biomass, suitable for use as fuel for power generation. Hazelnuts, for example, have very dense nut shells which make excellent fuel; in addition, the wood from periodic coppicing will also be available for biomass fuels. This ready availability could help stimulate a renewable biomass power industry, which would decrease reliance on fossil fuels (and incidentally add another positive effect in regard to global warming, not included in the calculations above).
Wildlife Habitat
The exchange of biologically sterile, bare soil fields for fields consisting of permanent stands of woody plants or trees would greatly increase living space and cover for a great variety of wildlife, from songbirds to deer. Please note that woody agriculture will still require weed and pest control from time to time, and it should not be imagined that intensively cropped woody fields will support wildlife in the same fashion that an undisturbed natural habitat will. Many animals can adapt to a small amount of periodic disturbance, however, but can never adapt to a plowed field.