Transcript of "Agroforestry Optons for Small Upland Farms"
2 1 3 Sustainable Agriculture for the Golden Triangle Agroforestry Options for Small Upland Farms Richard R. Burnette Upland Holistic Development Project April 2006 Production Assistance: Ellen Burnette Jamlong Pawkham Sureerat Daengkhieo Technical Reviewers: Jeff Rutherford - CMU Social Research Institute Kevin Woods - Images Asia Environment Desk Chutima Chandarat - ISDSI Mark Ritchie - ISDSI Barry Flaming - Raks Thai Foundation Chomchuan Boonrahong - ISAC David Crist - CSF Klaus Prinz - McKean Rehabilitation Center Bob Morikawa - Floresta Illustrations: James Tong The production of this publication was made possible through major sup- port from Floresta (www.ﬂoresta.org)
4 1 5 Contents Contents Introduction 8 Summary and Conclusions 38 1. Agroforestry for Sustainable Hill Fields and Orchards 10 Appendix 40 1.1 Agroforestry and Soil Conservation in Hill Fields 11 Useful Plants Commonly Integrated into Agroforest 1.2 Agroforestry and Soil Improvement in Hill Fields 13 Sites in Northern Thailand 1.3 Agroforestry and Crop Diversiﬁcation in Hill Fields and Orchards 17 References 48 2. Other Applications of Upland Agroforestry 20 2.1 Hill Fallow Agroforests 20 Glossary of important terms 53 2.2 Home Agroforest Gardens 22 2.3 Degraded Woodland Agroforests 25 3. Management of Family Agroforest Plots 3.1 Seeking Tenure 27 27 Figures 3.2 Selection of Agroforest Species 28 3.3 Planning the Density and Arrangement of 1. Key agroforest crops for soil conservation in contoured Agroforest Plantings 29 hedgerows 13 3.4 Establishment of Family Agroforest Plots 30 3.5 Long-Term Management (weed control, 2. Key crops for diversiﬁed hill ﬁelds and agroforest orchards light/shade management, ﬁre control) 30 hedgerows 19 3. Key crops found in hill fallow agroforests 22 4. Family Nurseries for the Production of Agroforest Species 33 4. Key crops found in home agroforest gardens 24 5. Key crops found in degraded woodland agroforests 26 5. Community Participation 35 6. Comparison of management and production components related to four agroforestry systems 37 6. Marketing of Agroforest Products 36
6 1 7 Illustrations Illustrations 1. Bamboo, an important forest product, is essential for a wide 12. Stand of young, introduced fan palm, black sugar palm variety of purposes such as basket weaving. 8 and rattan in a degraded woodland agroforest. 25 2. Sustainable hill ﬁelds may contain soil conservation strips, 13. Family agroforest plots should be clearly designated. 27 soil-improving legumes and diversiﬁed crops. 10 14. A diverse, new agroforest planting. 29 3. Contour hedgerows 11 15. Selective thinning within family agroforest plot. 31 4. Mixed planting of pineapple and papaya among crop residues within a contour strip. 12 16. Family agroforest nursery 33 5. Certain viny legume species may be integrated early within 17. Community-wide cooperation is essential for agroforestry a corn crop to control weeds through the rainy season. 14 efforts with widespread beneﬁts. 35 6. Mature rice bean offers additional income as well as 18. A bed of recently emerged ﬁsh tail palm in a family nursery 36 serving as a green manure cover crop. 15 19. Indigenous Burmese grape adds to the biodiversity of a 7. Decreasing soil-damaging, intensive tillage is possible family agroforest plot. 39 through the use of viny legume cover crops. 17 20. Uncle Tisae displaying mature rattan canes in his productive 8. Diversiﬁed hill ﬁeld with corn, orchard crops (tea, banana, agroforest. 43 pineapple) and forest crops (rattan and Indian trumpet). 18 9. Hill fallow agroforest plot with tea, rattan, prickly ash and fan palm as well as natural pioneer and successive species. 20 10. Home agroforest garden with annual vegetables, herbs, snowﬂake tree and clerodendrum. 22 11. Palaung woman in front of stand of bitter rattan in her home agroforest garden. 23
8 1 9 both, and in which there are both ecological and economic interactions Introduction between the tree and non-tree components of the system” (Young 1989). The hilltribes of the Golden Triangle* have always depended upon Agroforestry in the Golden Triangle utilizes both woody and herbaceous the forest. The once vast woodlands of the region have been the grocery, plants incorporated as mixtures of indigenous forest species and compatible pharmacy and hardware store for upland people, supplying practically all non-native crops. Along these lines, a number of notable agroforestry of their needs (Illustration 1). Additionally, ecosystems associated with practices are enabling many upland farmers to sustain the productivity of the biodiverse deciduous and evergreen forests also restore depleted hill their hill ﬁelds, home gardens, orchards and mixed forest plantings. ﬁeld soils during each 5-15 year forest fallow that is essential for traditional swidden agriculture. The various agroforestry approaches described in this publication enable sustained productivity due to the following reasons: Unfortunately, forest resources in the region are under threat. Encroachment and unsustainable agriculture, particularly commercial fruit plantations, ► Such systems can be adapted to various sites regardless of size, have contributed to widespread forest devastation. Consequently, including hill ﬁelds and orchards, small spaces around village homes as signiﬁcant numbers of upland communities are facing the loss of forests well as both degraded and healthy forests making more efﬁcient use of and accompanying forest products that hilltribe people took for granted not not only space, but light and soil nutrients by the use of various species in too many years ago. different niches. ► These agroforests are highly biodiverse, incorporating mainly native Despite dwindling forest species as well as other hardy plant varieties that are adapted to local forest resources, various conditions and require few, if any, inputs for sustainable production. agroforestry options are ► Most plant species in indigenous agroforest systems are well known currently enhancing the to upland farmers, therefore such systems are more likely to be readily traditional, forest-dependant implemented and replicated. livelihoods of upland people. ► Depending on the overall diversity of agroforest species in each Agroforestry can be deﬁned site, productivity can be maintained throughout the year. as “a collective name for land-use systems in which ► Products (e.g. food and materials) from these agroforest systems woody perennials (trees, are generally in local demand and, therefore, do not require costly or long- shrubs, etc.) are grown in distance marketing channels. association with herbaceous Illustration 1 Bamboo, an important forest product, is essential plants (crops, pastures) for a wide variety of purposes such as basket weaving and/or livestock in a spatial arrangement, a rotation or * The Golden Triangle is a popular term referring to the general area where the coun- tries of Thailand, Burma (Myanmar) and Laos meet. Despite the climatic and cultural similari- ties that are found across the region, this booklet has greatest application to northern Thailand (17ْ -20ْ 30 north latitude and 97 ْ 20 -101 ْ 20 east longitude). Climatically, northern Thai- land is classiﬁed as Subtropical Moist Zone below 1,000 meters elevation and the Subtropical Lower Montane Belt, including Wet and Rain Forest Zones above that altitude (Holdridge et al. in Anderson).
10 1 11 Agroforestry plays a role in each of these three sustainable upland 1. Agroforestry for Sustain- farming emphases. able Hill Fields and Orchards 1.1 Agroforestry and Soil Conservation in Hill Fields Besides dwindling forest resources, hill ﬁeld cultivation by farmers throughout the region is also at risk. Traditionally, hill ﬁelds were farmed Most upland ﬁelds are located on considerably steep land for which long- rotationally, whereby clearings that had begun to degrade after a few years term sustainability will require an appropriate soil conservation measure. of cultivation would be allowed to return to a forest fallow. Over periods One alternative is an agroforestry approach known as alley cropping. This of 5 to 15 years, such abandoned hill ﬁeld plots would reforest naturally, technology involves the establishment of a series of contour hedgerows and in the process, allow the soil to recover. Based upon ongoing ecological comprised of fast growing nitrogen-ﬁxing trees (NFTs) (Illustration 3) regeneration, in areas with extensive amounts of forest and relatively small such as Leucaena diversifolia and Fleminga macrophylla or multi-stemmed populations, such swidden farming has been sustainable. grasses such as vetiver (Vetiveria zizanioides). Planted horizontally across steep ﬁelds, vegetative strips However, in an increasing comprised of these and fashion, forestry authorities similar plant species can are limiting the amount of form effective barriers against available land allocated for soil erosion. It is within the hill ﬁeld use per family. 4-10 meter wide bands or Such restricted available alleys, located between each land makes fallows of vegetative strip, that crops even a few years difﬁcult are grown. The width of to implement. Farmers are the alleys depends largely often left with degraded hill upon the steepness of the ﬁelds that are only a fraction ﬁeld; the steeper the ﬁeld of a hectare in size. Without the narrower the alley. Illustration 3 Contour hedgerows.Illustration 2 Sustainable hill ﬁelds may contain soil conservation any sustainable upland ﬁeldstrips, soil-improving legumes and diversiﬁed crops. cropping alternatives, the A major limitation to alley cropping is that it is often difﬁcult to locate usual long-term options are and/or produce adequate amounts of NFT seeds or other propagation stock to convert production to certain over-planted, monocropped fruit tree needed to establish and maintain hedgerows. Another drawback is the time varieties, or eventually abandon the degraded land. and labor required to maintain hedgerow plants (e.g, occasional weeding, regular trimming, replanting). With no opportunity for a forest fallow for long-term sustainable crop production, it is recommended that these upland ﬁelds be farmed with an Additionally, farmers who cultivate limited amounts of land also complain emphasis on three basic practices (Illustration 2): that hedgerows comprised of only NFTs or vetivier, despite serving a ► soil conservation valuable purpose with regards to soil conservation, consume too much ► soil improvement precious farmland without offering other beneﬁts. A limited exception, ► crop diversiﬁcation
12 1 13 however, is fodder production for livestock from certain NFT and grass Multi-Stemmed Grassy Species Broadleaf Food- Producing species within hedgerows, e.g., napier grass (Pennisetum purpureum), Lemon grass Species during the rainy season. Napier Papaya Vetiver Pineapple One multi-purpose agroforestry alternative, though, is to establish mixed Broom grass Key agroforest Rattan plantings of minimal-shading, food-producing plants such as papaya, crops for soil Indian trumpet pineapple, rattan, Indian trumpet (Oroxylum indicum), lemon grass conservation NFT Species Tea (Cymbopogon citratus) and tea within the contour strips (Illustration 4). in contoured Leucaena hedgerows Most of these plants are valued by local farmers and are fairly easy to locate Flemingia and plant. Contour strips comprised of such plants not only contribute to Figure 1 Pigeon pea soil conservation, but also White hoarypea provide edible and marketable Indigofera products. For maximum soil conservation, gaps between the plants can be ﬁlled in 1.2 Agroforestry and Soil Improvement in Hill Fields with crop residues and native grasses. Broom grass In addition to soil conservation, alley cropping has been promoted as a (Thysanolaena latifolia), a means of improving soil condition and fertility through the production of native grass that produces biomass from NFT hedgerows. Nitrogen-ﬁxing plants (including NFTs) an inﬂorescence commonly absorb nitrogen, a major plant nutrient, into their tissues after air-borne harvested for local broom nitrogen is secured by special bacteria (Rhizobia) living in their roots. Such production, is one such plants do not require external sources of nitrogen for natural growth and candidate for incorporation development. Consequently, nitrogen-ﬁxers often thrive on less fertile soils Illustration 4 Mixed planting of pineapple and papaya among into contoured strips for soil and are the major source of nitrogen in many natural ecosystems. Related crop residues within a contour strip. conservation. to agriculture, nitrogen-ﬁxing plants provide signiﬁcant amounts of both nitrogen and soil-building organic matter, especially when plant tissues Overall, multi-stemmed grasses and NFTs hold topsoils best, especially are incorporated into the soil. So naturally, leaf and stem trimmings from on steeper slopes. However, the broader appeal of mixed hedgerows NFTs are important components in alley cropping. comprised of food-producing plants is derived from increased crop diversity and production. There are places in Southeast Asia where NFT hedgerow species are able to produce biomass year-round due to sufﬁcient soil moisture and other favorable climatic conditions. In such locations it is recommended that hedgerows be spaced sufﬁciently close (ﬁve meters or less) so as to produce enough NFT biomass to maintain soil fertility in hill ﬁelds (Palmer). However, since most areas in the Golden Triangle receive only 5-6 months of little or no rain, signiﬁcant NFT biomass production is restricted to the rainy season. Therefore, the application of NFT biomass alone from hedgerows
14 1 15 would have limited effect on hill ﬁeld fertility in this region. Additionally, after the corn has been planted, while the ﬁeld is still clean, in order to as close hedgerow spacings (no more than ﬁve meters) consume almost 20 minimize early competition between the legumes and the corn crop. percent or more of the area within hill ﬁelds, upland farmers with limited farmland are not generally inclined towards relying only upon green manures Jack bean tolerates shading and remains bushy rather than climbing the produced in NFT hedgerows. corn stalks, thereby offering excellent cover against rainy season weeds. However, mature jack beans, which contain a toxin, are not readily eaten and One indigenous alternative for the production of green manures in hill have no local market. Conversely, rice and lablab beans, which are edible ﬁelds is the practice of cover cropping with viny legume species. Upland and marketable, tend to climb farmers in the region have long planted legume cover crops such as rice corn stalks. However, up to bean (Vigna umbellata), black bean (Vigna Unguiculata) and lablab bean three months after planting, (Lablab purpureus). The establishment of these viny legume species allows the vines of these two beans the ﬁxation of nitrogen at impressive rates (approximately 80-130 kg/ha should be gently beaten down (Bunch),) greatly increases levels of soil organic matter, and smothers at least twice so as to gain out weeds. better coverage of the soil surface. Managing the spread In northern Thailand, of rice and lablab bean vines signiﬁcant numbers of is much easier than hoeing upland farmers practice weeds and less expensive relay-cropping, a form of than applying herbicides or accelerated seasonal fallow, the labor needed for weed Illustration 6 Mature rice bean offers additional income as on permanent hill ﬁelds control. well as serving as a green manure cover crop. in which traditional forest fallow is no longer possible. When comparing preferences as well as the pros and cons of relay-cropping Under such a system, legumes and early integration of corn and beans, relay-cropping is largely preferred are planted thickly in corn by farmers who use herbicides to kill heavy stands of late rainy season ﬁelds about a month before weeds in corn ﬁelds prior to planting the bean crop. Farmers observed the maize is harvested. The that both rice and lablab beans that are relay-cropped with corn will grow legumes are valued for their and produce more vigorously than the same varieties that are integrated Illustration 5 Certain viny legume species may be integrated early within a corn crop to control weeds through the rainy soil improvement properties, earlier in corn ﬁelds. But without herbicides, effective weed control that season. such as nitrogen ﬁxation and is needed prior to establishing stands of relay-cropped beans in cornﬁelds organic matter production, will require signiﬁcant labor. So, if farmers prefer herbicide-free corn as well as the income derived from the sale of the dried beans. and bean production then they may be more inclined to select the earlier- established system of integrated beans, even though production may be So as to better control weeds throughout most of the rainy season, less than that of relay-cropped beans. certain viny legumes, particularly rice bean, lablab bean and jack bean (Canavalia ensiformis), may also be integrated earlier within the corn crop. (Illustration 5) As such, the beans should be established 1-2 weeks
16 1 17 In permanent hill ﬁelds where traditional forest fallows are no longer corn and beans helps maintain some degree of upland rice production possible, as long as there is adequate soil fertility, most hilltribe farmers on small upland farms. prefer growing the staple of upland rice. However, when soil fertility is depleted after a few years of upland rice production, many farmers elect Besides the use of green manures, refraining from seasonal burning, to grow relay-cropped corn and viny legumes. One obvious reason is that avoiding intensive tillage (Illustration 7) and decreasing the use of ﬁeld corn and dried beans are marketable. Another reason is that ﬁeld corn herbicides are important soil improvement practices. A no-burn tolerates somewhat poor soil conditions. But a very important reason is that approach enables plant residues to be farmers appreciate the overall converted into soil-building organic soil-improving effect of the matter. Minimal tillage (or no-till) helps Use of Salt as a Weed Killer in Upland beans, even when viny legumes to conserve soil structure and decreases Rice Fields are grown in combination with a the risk of soil erosion. And the lack of corn crop. Farmers report that herbicides (particularly through the use of Whereas viny legumes cannot be integrated after relay cropping over a few cover crops) encourages a healthier soil into upland rice ﬁelds to control weeds as years, that soil fertility often ecosystem that is rich with indigenous effectively as in as in corn ﬁelds, are there improves enough to allow 1-2 soil ﬂora and fauna. The ultimate goal any chemical-free options for controlling years of upland rice production is that each hill ﬁeld will contain topsoil weeds in upland rice? For the past few before relay-cropping of corn that is dark, loamy and friable; rich in decades upland farmers in northern Thailand and beans is needed again. roots, earthworms and other creatures have been spraying a solution of common salt (NaCl) at a rate of approximately 2 kg of that loosen the soil and in which essential Illustration 7 Decreasing soil-damaging, salt per 20 liters of water (with 2 tablespoons Although it is possible to plant nutrients are always accessible to intensive tillage is possible through the use of integrate light mixtures of the ﬁeld crops. viny legume cover crops. of detergent mixed in). Application with a pack back sprayer is done on a sunny legumes such as cowpea and day about 1-2 months after the rice is pigeon pea in upland rice stands planted. The spray is applied directly to the for crop diversiﬁcation purposes, 1.3 Agroforestry and Crop Diversiﬁcation in Hill Fields weeds, avoiding the rice plants. The salt the degree of nitrogen ﬁxation and Orchards water solution effectively controls several and overall soil improvement common broadleaf weeds such as Ageratum. provided by intercropped legumes The third agroforestry-related emphasis in sustainable upland farming However, there are many broadleaf weed is too small to enable continuous is to increase the diversiﬁcation of crops in hill ﬁelds and orchards. species, as well as most grassy weeds, that upland rice production year after Regarding ﬁeld crops, the priority of most hilltribe farmers in this region are not killed. But does the salt application have a negative effect on the soil? Research year. Therefore, as increasing is to produce upland rice and ﬁeld corn as well as marketable and edible by Mae Jo University conﬁrms that the numbers of upland farmers legumes. Traditionally, upland farmers have integrated these main ﬁeld crops sprayed salt is leached out of the soil over now lack adequate land so as with various secondary annual crops such as pumpkins, cowpeas, melons, the rainy season. Obviously, salt solution to allow their hill ﬁelds to go chilies and sesame. It’s also common to see perennials, such as banana, is not a broad spectrum weed killer, but it undergo traditional forest fallow, papaya and other fruit trees scattered throughout hill ﬁelds in arrangements does offer upland rice farmers a means of the option of alternating a year known as dispersed tree systems. lessening the use of chemical herbicides or two of rice production with (Van Keer, et al.). a few years of relay-cropped
18 1 19 Hill ﬁeld diversity can be further increased by the addition of various Indigenous forest species indigenous forest species that offer non-timber forest products (Illustration rattan bamboo 8). Many types of forest plants, such as rattan and forest pepper (Piper prickly ash tea retrofractum), grow quite well in full to partial sun. Being native, they forest pepper fan palm require no extra watering, are adapted to local soils and have few pests. Figure 2 Indian trumpet longan Whether adequately scattered throughout hill ﬁelds to reduce competition mafai bael fruit with the main crops or planted intensively within vegetative strips for soil conservation purposes, such diversiﬁed plantings will help extend Key crops production throughout the year. for diversiﬁed hill ﬁelds and agroforest Perennial orchard and ﬁeld crop species orchards Unfortunately, in recent pigeon pea pomelo hedgerows years, many upland farmers papaya cassava with limited acreage have Annual ﬁeld crop species litchee lemon grass turned to monoculture wax gourd jack bean pineapple banana production of fruit trees pumpkin lablab bean coffee mango such as litchee and longan. upland rice sorghum Such single-specie plantings rice bean cowpea obviously lack diversity and corn chili pepper are economically risky, putting farmers at particular risk during years of poor production or In summary, the objectives of establishing diversiﬁed hill ﬁelds and low market prices. A more agroforest orchards are to:Illustration 8 Diversiﬁed hill ﬁeld with corn, orchard crops sustainable alternative is to(tea, banana, pineapple) and forest crops (rattan and Indian establish agroforest orchardtrumpet). ► increase overall sustainability of upland farming plantings by growing select ► lower the risk of complete crop failure non-timber forest species along with the orchard crops. ► increase overall crop production with a broad selection of products throughout the year ► increase household food sufﬁciency As in the diversiﬁed hill ﬁeld plantings, various forest species (rattan, ► increase family income forest pepper, fan palm, etc.) can be planted among the dominant orchard ► Provide farmers with crop systems that closely reﬂect traditional trees, along with other fairly shade-tolerant crops such as tea and pineapple. forest-dependent farming systems as well as the ecology of local forests However, the canopy of the dominant fruit trees should be pruned so as to allow ﬁltered sunlight to reach the shorter crops as very few species are productive in complete shade.
20 1 21 weeds being cut back occasionally). Within a few years, the old ﬁelds 2. Other Applications of are transformed into secondary forests, each ﬁlled with a mixture of useful plants (Illustration 9). Upland Agroforestry The main beneﬁt of this permanent fallow is that if managed well, these Agroforestry is not limited to hill ﬁelds and orchards. It can also be former hill ﬁelds never cease to be productive in some capacity. For adapted to various other sites, such as home gardens. Another version of example, plantings of quicker maturing pineapple, papaya and banana can agroforestry involves mixed plantings of both native forest species and be harvested within 1-2 years. Tea trees become productive within 3 years. select horticultural crops within wooded or semi-wooded settings. Again, Native forest peppers as well as edible rattan and bamboo shoots can be regardless of the agroforest application, the stress is upon increasing family harvested within 3-4 years. Depending on the species, rattan and bamboo food sufﬁciency and income through ecologically sustainable means. canes are harvestable within 4-8 years. This section introduces a few basic types of agroforestry applications These biodiverse plots may begin to attain a healthy forest appearance found on many small upland farms in northern Thailand, including: between 5-10 years. As the shade increases, some plants, such as pineapple, will begin to phase out as slower growing forest species, including rattan, ► Hill fallow agroforests black sugar palm (Arenga westerhoutii) and fan palm (Livistona speciosa) ► Home agroforest gardens begin to mature and become productive. However, useful agroforest crops ► Degraded woodland agroforests may be added continually. Ultimately, farmers may choose to allow these diversiﬁed fallow hill ﬁeld plantings to remain as productive agroforests or, after several years of fallow, they may clear the land again for swidden 2.1 Hill Fallow Agroforests agriculture. In response to less access to One important issue, however, is whether hill fallow agroforests should productive forests as well as be allowed to attain a predominantly forest appearance. Many highlanders adequate land for traditional hold concerns that once a former hill ﬁeld plot achieves an appearance rotational agriculture, some of forest fallow then local forestry ofﬁcials may not allow the previous local farmers are now cultivator to continue to utilize the land for traditional agriculture or even practicing another indigenous agroforestry. form of agroforestry. Prior to allowing their hill ﬁelds Without clear state land use policies for forest communities within to revert to forest, these reserve forests or national parks, residents should seek dialogue with local farmers establish mixed authorities regarding allowable practices related to rotational farming and stands of useful forest the establishment of hill fallow agroforests. And in locations where the plants and shade-tolerant use of fallow land for hill fallow agroforestry remains in question, the Illustration 9 Hill fallow agroforest plot with tea, rattan, prickly perennial crops in among establishment of agroforest orchards on previous farmland may offer a ash and fan palm as well as natural pioneer and successive the upland rice and corn. more secure alternative. species. Once the plots are no longer planted in ﬁeld crops, natural
22 1 23 Long-term crops and medicinal herbs are either low growing or produce root crops. rattan prickly ash Many other types, such as various perennial eggplants, are bushy and tea fan palm grow to medium heights. Fruit trees, such a papaya and jackfruit, in forest pepper bamboo addition to clumps of bamboo and certain palms, grow taller, which snow ﬂake tree mafai form the canopy of home agroforest gardens. Short-term crops forest banana coffee upland rice cucumber Besides common fruit pumpkin pineapple Key crops found and vegetable varieties, cowpea banana in hill such as pineapple, pumpkin chili pepper corn fallow agroforests and long bean, a signiﬁcant sorghum papaya Figure 3 portion of home agroforest gardens may be made up of indigenous forest species. Many of these indigenous plants adapt well to varying 2.2 Home Agroforest Gardens amounts of shade. Native, perennial food-producers Increasing numbers of upland families lack access to farmland with many include those with edible leaf barely managing to survive on meager incomes from seasonal commercial shoots and ﬂowers, such as a Illustration 11 Palaung woman in front of stand of bitter rattan plantation work. So as to supplement family diets, through backyard few ﬁg varieties (e.g., Ficus in her home agroforest garden. agriculture, some households are making efﬁcient use of cramped spaces virens, F. racemosa) as well around their homes for supplemental food production and income despite as Acacia pennata, Clerodendrum glandulosum, kassod tree (Senna siamea), overcrowding, shade and limited water. Home agroforest gardens are important katuk (Sauropus androgynus) and snowﬂake tree (Trevesia palmata). components of backyard agriculture systems. A major beneﬁt of planting such variety of forest plants in home agroforest gardens is the production of edible leaves and shoots throughout the year. Home agroforest gardens This is particularly important during the dry season when conventional of less than 50 square meters shallow-rooted garden crops often lack adequate water to survive. may have a multi-storied mixture of at least 10-20 Of course, home agroforest gardens do not have to be restricted to food-producing plants limited spaces adjoining village homes. Some households have established (Illustration 10). Some similar intensively mixed plantings in larger areas (1/2 rai* or more) for the species, such as leaf pepper production of food and to increase family income. (Piper sarmentosum), sweet potato, forest yams, konjac Home agroforest gardens are not limited to food production only. In Illustration 10 Home agroforest garden with annual vegetables, (Amorphophallus paeoniifolius) the Golden Triangle, women of the Palaung hilltribe seek rattan strips with herbs, snowﬂake tree and clerodendrum. as well as numerous cooking * 1 rai = 0.16 hectare
24 1 25 which to fashion belt-like hoops that are an important component of their 2.3 Degraded Woodland Agroforests traditional dress. So besides growing only edible plants, some Palaung households include faster growing, cane-producing rattan such as bitter Near upland communities, patches of degraded woodlands covered rattan (Calamus siamensis) in their backyard agroforest gardens for personal with trees, brush or grass are sometimes available on which to plant family use or to sell (Illustration 11). Additionally, it’s not uncommon for hilltribe agroforest plots. Such land may be off limits or unsuitable for conventional families to grow backyard clumps of bamboo in order to produce construction ﬁeld or orchard crop production. However, these areas might support select materials and edible shoots. Some household plots include fan palms with agroforest crops and thereby increase overall productivity. leaves that can be made into a durable type of roof thatch. Such sites may be selectively The amount of plant diversity within hilltribe gardens can be astounding. cleared so as to maintain some Anderson reports having counted more than 90 species of plants in various of the indigenous vegetation upland gardens and villages of the region. along with a mixture of introduced agroforest plants (Illustration 12). Many of the useful indigenous woody plants often found on such Non-indigenous perennial species sites include bamboos (for pineapple jackfruit construction, weaving, ﬁber pomelo lemon grass Figure 4 and edible shoots) as well moringa guava as native oaks, chestnuts banana eggplant and chinkapins that produce Illustration 12 Stand of young, introduced fan palm, black sesbania passion fruit Indigenous forest species edible and marketable sugar palm and rattan in a degraded woodland agroforest. Key crops nuts. Additionally, various cha-om forest yam found in home smooth ﬁg red shoot ﬁg agroforest medicinal herbs and wild vegetables, such as ferns, are often present. Any clerodendrum ﬁsh tail palm gardens useful, pre-existing plants should not be cut but rather incorporated into taro leaf pepper Non-indigenous annual species the care and management of the agroforest plots. katuk snow ﬂake tree ivy gourd pumpkin chili pepper roselle Larger indigenous trees, though possibly lacking edible or otherwise sweet potato bottle gourd useful products, should be preserved in such plots as they contribute to the balsam pear long bean overall forest integrity. Such trees will also produce considerable leaf melon cucumber fall that will biodegrade into nutrient-rich humus for the beneﬁt of the companion plants growing in the understory. Additionally, with cool, foggy mornings during the early dry season, tree foliage captures condensation from the moist air. Trees enable moisture to be recycled back into the topsoil of the agroforest plots as seen when water drips off of the leaves. Consequently, when compared to non-wooded plots, the soil underneath trees generally retains moisture longer into the dry season, thereby beneﬁting
26 1 27 crops in woodland agroforest plantings. Additionally, larger trees serve as perches for birds which also help in the natural establishment of 3. Management of Family plants in the plots. Agroforest Plots However, there will be likely competition from the larger and/or more numerous pre-existing plants for sunlight, nutrients and water. Such 3.1 Seeking Tenure competition can result in potentially slow and stunted growth for the Besides farming, many hilltribe communities have a strong interest in introduced agroforest species. As a result, certain non-forest agroforest participating in local forest management. Unfortunately, due to unattained crops best suited to sunnier environments (i.e., papaya, pineapple) may not citizenship and the absence of a national community forestry policy that adapt well to plots where considerable shade is already present. clearly allows agroforestry and other forms of agriculture in designated protected forest areas, most hilltribe households in the region are still Therefore, sites with considerable amounts of pre-existing of bamboo, denied ownership or full legal access to the land around their communities. grasses or other proliﬁc types of vegetation will require a signiﬁcant amount Still, many would-be agroforesters are willing to access almost any type of thinning if introduced species are to be grown in association with these of land that’s available; whether their own backyards or plots of degraded natives. Ultimately, farmers may decide that certain plots with extremely forestland. thick stands of bamboo may be best suited only for the production of bamboo poles and shoots. Depending upon the availability of land, non-backyard agroforest plots may be as small as a fraction of a hectare. But regardless of the size, unless Another special challenge for mixed woodland plantings includes the plots are located in areas where some degree of tenure already exists (e.g., in potential for dry season wildﬁres. The development and maintenance of and around long established ﬁre breaks are mandatory activities in degraded woodland agroforests. upland ﬁelds) permission Indigenous forest species must be sought from local black sugar palm tea authorities for the establishment rattan ﬁsh tail palm of family agroforest plots. bamboo forest yam After permission has been Figure 5 forest banana fan palm received and land divided snow ﬂake tree prickly ash among participating families, Key crops found in each plot should be clearly degraded woodland marked with signs to agroforests designate the owner and to request others to respect the Non-indigenous species resources within (Illustration Illustration 13 Family agroforest plots should be clearly pineapple jackfruit 13). designated. Tree of Heaven pomelo mango neem coffee fragrant screw pine passion fruit perennial eggplant
28 1 29 3.2 Selection of Agroforest Species 3.3 Planning the Density and Arrangement of Agroforest Plantings Forest management is often equated with the production of a single forest crop species; basically tree farming. Timber species such as teak, pine and The density of plantings will depend upon the availability of seedlings, eucalyptus are commonly grown in such fashion. Additionally, monocropped the types of agroforest plants to be established and the plant cover already plots of indigenous food-producing species, particularly cha-om (edible leaf existing within the plots. Given the scarcity of available land for family shoots), rattan (edible cane shoots), fruit-producing longan and bael fruit agroforestry in many upland communities, it is recommended that plants be as well as tea are often encountered. Despite being composed of native established as closely together as possible while minimizing competition. plants and therefore better adapted to local conditions, these monocropped Species that have large canopies at maturity, such as black sugar palm, or plantations lack the biodiversity that many upland farmers prefer. On the plants that are prone to spread (i.e., rattan and various bamboos), should contrary, diversiﬁed agroforest systems are generally rich in a variety of be spaced no less than 5-6 meters apart. However, various smaller species, catch crops should main crops fail for any reason. such a snowﬂake tree, tea and coffee can be established much closer (i.e., every 1 ½ - 2 meters) and even scattered between larger agroforest plants The choice of plants to include in biodiverse family agroforest plots (Illustration 14). will depend on the objectives of each household. Other factors related to plant choice include the agroforest products in demand as well as local Smaller viny plants, such as forest yams and native peppers, are space community forest policies. For example, some communities may limit efﬁcient as they can grow up tree trunks. Pineapple and leaf pepper can the inclusion of certain fruit trees, such as litchee or tangerine, so as to be planted very densely, particularly in plots that are somewhat open and prevent sites designated for agroforestry from becoming orchards. Another less shady. Given efﬁcient key consideration is the availability of various types of agroforest plant selection and arrangement seedlings such as rattan or tea. However, the ultimate factors are the local of plants, every square climate and the physical characteristics of the each site, including seasonal meter within multi-storied soil moisture, exposure to sunlight, soil quality and resident plants. family agroforest plots can be occupied by productive Each agroforester needs to know the site requirements of each plant forest and horticultural species. Certain forest plants, such as various types of rattan and bamboo, plants. forest pepper, ﬁshtail palm and snowﬂake tree prefer somewhat unexposed, moist sites such as north slopes and creek bottoms. Others, including However, bamboos may Indian trumpet, fan palm, prickly ash (Zanthoxylum rhetsa) and white thorn limit the overall density of rattan (Calamus viminalis) grow well in well-drained, sunny locations. agroforest plantings. Typically Regarding elevation, in northern Thailand, arabica coffee performs best aggressive spreaders, bamboo Illustration 14 A diverse, new agroforest planting. in the highlands above 800 meters whereas tea adapts to both higher and plants produce substantial lower elevations (down to approximately 500 meters). shade and have extensive root systems that out-compete most other agroforest species. Because bamboos play a very important role in agroforesty, they should be managed through the segregation of clumps away from most other species and/or by limiting the spread of clumps via the harvest of shoots and poles as well as by culling less desirable growth.
30 1 31 3.4 Establishment of Family Agroforest Plots Unfortunately, excessive shade is detrimental to many forest species, especially at the seedling stage. Overly shaded seedlings may grow Hardened seedlings (i.e., those that have been gradually acclimatized extremely slow or remain stunted, thereby delaying potential beneﬁts from to ﬁeld conditions) should be planted during the early-mid rainy season agroforest plantings. (mid June-early August). Young established plants need to be clearly marked so as to be protected during occasional weeding. Therefore, light management is another important consideration. As mentioned previously, in degraded woodland agroforests where resident Depending on factors such as the presence of weeds such as imperata grass trees are already quite large and/or where there are aggressive fast-growing and the degree of sunlight/shade, weed control (slashing weeds and digging species such as bamboo, thinning will be needed so as to allow at least 50 out roots) will be necessary at least 3 to 6 times per year, particularly during percent ﬁltered sunlight to penetrate into the understory. However, where the rainy season. Weed control will be needed each year until weeds have thinning and partial clearing begun to be shaded by established plants. are employed to facilitate agroforest plantings, care So as to develop agroforest sites with a strong forest integrity (in contrast must be taken not to allow to conventional orchard plantings), most of the plants within agroforest the forest integrity to degrade plots, whether planted or having been naturally established, should be native (Illustration 15). Should there forest species. The most efﬁcient means of restoring forest plants in family appear to be excessive harm agroforest plots is to use the technique employed by farmers establishing hill done to the forest associated fallow agroforests. After planting an initial stand of desired, productive with the management of agroforest species in appropriate densities they allow nature to take its agroforest plots, increased course. In the long run, allowing various pioneer and successive species risk of conﬂict between to establish themselves and ﬁll in the gaps is easier than attempting to upland communities and local replant an entire forest plot. forestry authorities is likely. Illustration 15 Selective thinning within family agroforest Therefore, so as to minimize plot. damage to the forest, only 3.5 Long-Term Management partial thinning of the undergrowth as well as limited trimming of limbs and branches of larger trees should be occasionally done to allow increased Regarding pioneer species, natural stands of aggressive weeds, such penetration of sunlight for improved agroforest production. Trimmings as imperata, can smother out small agroforest seedlings, making weed can be used as ﬁrewood and fodder or for construction. management mandatory. One efﬁcient means of controlling weeds, thereby reducing frequent weed cutting and ultimately providing agroforest seedlings Fire Management is another priority related to agroforestry. Within a a better chance of survival and good growth, is to establish a stand of fast- few minutes a wind-driven ﬁre can wipe out all of the established agroforest growing, shade-producing trees such as kassod tree (Senna siamea). If plants in a plot. Unlike bamboo, certain crops such as tea and rattan simply planted densely enough (approximately every 1 ½ -2 meters), and weeded cannot tolerate ﬁre. From the beginning of the dry season, ﬁre breaks must as necessary during the ﬁrst 1-2 years of establishment, within a few years be established and maintained around entire community forests as well as the young trees will begin to form a canopy. The resulting shade will each family agroforest plot. curb even most aggressive weeds, including imperata.
32 1 33 Fire breaks, with recommended widths of 10-15 m, should be established around each family agroforest at the beginning of the dry season. The Forest 4. Family Nurseries for the Restoration Research Unit recommends slashing vegetation along the two edges of the ﬁre break, piling it up in the middle and burning it. Meanwhile, Production of Agroforest Species adequate numbers of persons, tools and water sprayers should be on hand to control any ﬁre that escapes during the process. During the remainder of The establishment of nurseries within each community is essential the dry season, community ﬁre watches should be in place with strategically for family agroforestry programming so as to foster self-sufﬁciency and located barrels of water and ﬁreﬁghting tools at ready. Also, each ﬁre break sustainability. Family nurseries may also help generate additional income should be occasionally swept of dry leaves until the rains return. from the sale of seedlings (Illustration 16). Despite the potential damage to agroforests, orchards and the top soil Besides possessing familiarity with local forest species, most hilltribe of ﬁelds due to ﬁres, many people consider burning to be a useful land agroforesters already hold indigenous knowledge related to plant management tool, claiming improved production of wild mushrooms and propagation. What may be lacking, however, are various materials and other desired forest products. Therefore, ﬁre should only be used on a equipment needed to establish family agroforest nurseries, including: limited basis with extreme discretion. Communities should also develop policies related to the use of ﬁre in agriculture, forest management and ► Shade cloth, wire and nails even hunting. Fines and other penalties must be imposed in cases when ► Tools and equipment (e.g., wheelbarrows, shovels, hoes, buckets, ﬁre is misused, particularly where damage to property occurs. water hoses, watering cans) ► Materials such as seedling bags and plastic basins for propagation ► Barrels in which to store water and produce natural fertilizers (manure/compost teas) ► Air-tight containers in which to store certain types of seeds A major limitation to upland nursery management is the shortage of water, especially during the dry season. Water storage in barrels and tanks is a necessary precaution. Another challenge is locating seeds and cuttings for many increasingly rare forest species. It is illegal to remove plant stock from protected forests. However, Illustration 16 Family agroforest nursery desired species can often be found within upland
34 1 35 upland communities and farms. Therefore, networking and bartering are useful for locating and obtaining hard-to-ﬁnd plant stock. Addi- 5. Community Participation tionally, understanding the ﬂowering and fruiting schedules of desired For effective agroforestry programming, it is essential that upland plant species as well as the storage and propagation requirements of communities work together to agree on common goals. Residents must each type of seed is vital. outline strategies related to seeking and/or strengthening land and forest tenure. With local authorities, they should negotiate appropriate agroforest Given adequate skills, proper equipment, reliable water supplies and viable activities within designated community forests. Additionally, equitable plant materials, a surprisingly large number of seedlings can be produced in distribution of family agroforest plots among participating residents will a small family nursery. However, plant propagation should not be restricted be needed. And, collectively, they must determine their own community to nurseries only. Many upland agroforesters are experts at scattering seeds forest policies. of various forest species such as tea and rattan in appropriate sites for more efﬁcient and natural crop establishment. Wildlings of rattan, prickly ash Related to the implementation of agroforestry, so as to conserve labor and and other species may also be located and transplanted within agroforest improve overall production, families might cooperate further to facilitate: plots. Additionally, farmers are known to stick root and stem cuttings of various species, including forest pepper, snow ﬂake tree and bamboos for ► The establishment of agroforest plots establishment in appropriate sites during the rainy season. ► Fire prevention ► Protection against theft and vandalism ► The harvest of family agroforest products Illustration 17 Community-wide cooperation is essential for agroforestry efforts with widespread beneﬁts.
36 1 37 6. Marketing of Agroforest Figure 6 agroforests woodland Degraded gardens agroforest Home agroforests Hill fallow orchards agroforest hill ﬁelds and Diversiﬁed system Agroforestry Products Community-wide participation will also be needed to determine viable markets for the sale of local agroforest products. Although the main high Medium- High high Medium- High products agroforest Diversity of priority of agroforestry is to improve family food sufﬁciency, a related goal is to increase family incomes through the sale of agroforest products. By and large, adequate regional demand exists for these goods in northern Comparison of management and production components Thailand. But while many agroforest products may be marketed locally high Medium- Low high Medium- medium Low- ments require- Fire control Light/shade (e.g., bamboo shoots and other types of forest produce), a few types, such as coffee, may require more distant and sophisticated marketing systems. related to four agroforestry systems In northern Thailand, there is considerable demand for raw materials, Medium-high Low Medium-high Low-medium requirements management such as rattan and bamboo, with which to make baskets and other handicrafts. Producers of such raw materials may have the choice of selling these products to manufacturers or producing value-added baskets and handicrafts themselves. Medium Low high Medium- high Medium- ments require- Labor ≥ ½ rai < ¼ rai ≥ ½ rai ≥ ½ rai ments require- Land Medium-high High Medium-high Medium-high crop densities Agroforest Medium-high Low-medium Medium-high High requirements agement Weed man- Illustration 18 A bed of recently emerged ﬁsh tail palm in a family nursery
A particular slide catching your eye?
Clipping is a handy way to collect important slides you want to go back to later.