Agroforestry Chapter 3: Shifting Cultivation, Improved Fallows and Taungya
Agroforestry Notes · Chapter 3
Chapter 3: Shifting Cultivation, Improved Fallows and Taungya
The oldest sequential systems: jhum and its regional names, land-use factor, why the system collapsed, improved fallows, and the taungya system with its history, types, merits and demerits.
1. Shifting cultivation
Shifting cultivationSystem of land use in which the site of cultivation is regularly changed, with older sites reverting to forest or bush fallow.Source: ICAR e-course, Glossary
Fallow (e-course)A period between crops during which land is rested from deliberate cropping. Natural vegetation may be allowed to grow or fallow species may be planted to provide soil cover and/or more rapid regeneration of soil.Source: ICAR e-course, Glossary
Fallow (Nair)Land resting from cropping, which may be grazed or left unused, often colonized by natural vegetation.Source: Nair (1993), Glossary
Also called slash-and-burn agriculture, it is the oldest and most widespread subsistence agroforestry system. A patch of forest is felled, the slash is dried and burnt, crops are grown for a few years and the land is then left to a long bush fallow in which trees and fertility return.
Selection of forest patch
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Felling and slashing (dry season)
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Burning: ash releases nutrients; pH, available P and bases rise
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Cropping for 2–3 years (mixed crops, dibbled)
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Yields fall: fertility loss, weeds, pests
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Abandonment and bush fallow (traditionally 10–20 years or more)
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Return to the regenerated site
Extent and stability
- About 360 Mha, or 30% of the world’s exploitable soils, supporting over 250 million people (FAO, 1982).
- Under low population the fallow:crop ratio could be 10:1 and the system was stable and ecologically sound.
- In India the fallow cycle has shrunk from 20–30 years to 2–3 years, so the land no longer recovers.
- Shifting cultivation caused about 70% of tropical deforestation in Africa (FAO, 1982).
Land-use intensity
Land-use factor L = (C + F) / C Cultivation factor R = C / (C + F)
C = years of cropping, F = years of fallow. With 2 years of crop and 18 years of fallow, L = 10 and R = 0.1. Under permanent cultivation L = 1. A falling L shows that fallows are getting shorter.
Why yields decline
Sanchez (1976) gave four reasons: soil fertility depletion, weed invasion, deterioration of soil physical properties and pests and diseases. The ash effect of burning is temporary, so the first crop benefits most.
Regional names
| Name | Region |
|---|---|
| Jhum / Jhuming | North-East India |
| Khallu / Kurwa | Jharkhand |
| Podu / Dahiya | Orissa, Andhra Pradesh |
| Bewar, Dippa, Penda, Kumri, Pothu | Other parts of India |
| Ladang | Indonesia, Malaysia |
| Ray / Rai | Vietnam, Thailand |
| Kaingin (Caingin) | Philippines |
| Chena | Sri Lanka |
| Taungya | Myanmar |
| Milpa | Mexico, Central America |
| Roca | Brazil |
| Masole | Zaire (Congo) |
| Tavy | Madagascar |
| Chitemene | Zambia, Zimbabwe, Tanzania |
Memory trick: J-K-P for India: Jhum (North-East), Kurwa/Khallu (Jharkhand), Podu (Orissa/Andhra). Milpa = Mexico; Chena = Ceylon (Sri Lanka).
Effects and control
Ill effects
- Deforestation and loss of biodiversity
- Soil erosion, landslides, silting of reservoirs
- Fall in organic matter and CEC
- Weed infestation and lower yields
Control measures
- Demonstrate permanent agriculture and terracing
- Allot land to tribal families
- Legal limits on steep slopes
- Animal husbandry, handicrafts and forest employment
- Introduce improved fallows and agroforestry
2. Improved fallows
Improved tree fallow (Nair)An improved tree fallow is a rotational system that uses preferred tree species as the fallow species (as opposed to colonization by natural vegetation), in rotation with cultivated crops as in traditional shifting cultivation.Source: Nair (1993), An Introduction to Agroforestry, Chapter 5
Fallows are crop land left without crops for one season to several years. An improved fallow replaces the slow natural regrowth with planted, preferably nitrogen-fixing, trees or shrubs that restore fertility faster and give some products such as fuelwood or stakes.
- Trees recycle nutrients better than herbaceous or grass fallows because their deep roots reach nutrients that crops cannot.
- Herbaceous green manures often failed because they do not survive the dry season; shrubs such as Cajanus cajan do.
- SW Nigeria: farmers retain Dactyladenia (Acioa) barteri, Alchornea, Dialium and Anthonotha as fertility restorers.
- Near Ibadan, Gliricidia sepium yam stakes took over the fallow and restored fertility faster.
- Ecuador: 2 years of crops, then 8 years of Inga edulis with banana and a grazed forage legume.
- NW India: Sesbania cannabina grown 65 days between wheat and rice added about 165 kg N/ha.
- Best soil-improving fallow trees (Young, 1989, first priority): Faidherbia albida, Leucaena leucocephala, Acacia auriculiformis, A. mearnsii, Flemingia macrophylla, Paraserianthes falcataria.
Kang and Wilson (1987) described six stages through which land use intensifies, from long natural fallow, through shortened and planted fallows and alley cropping, to permanent multistorey homegardens. Alley cropping is, in effect, a permanent improved fallow grown at the same time as the crop.
3. Taungya system
Taungyamethod of raising forest crops in combination with an agricultural crop; the agricultural use to which the land is put does not generally continue throughout the rotation of the forest crop but is confined to that period which ends with the closing of the canopy of the forest cropSource: ICAR e-course, Glossary
Taungya is a Burmese word: taung = hill and ya = cultivation. It was the local name for shifting cultivation and later for the method of raising forest plantations with field crops. Landless farmers grow crops between the young tree rows for 1–3 years until the canopy closes, and in return tend the trees. Wood is the ultimate goal; food is the farmer’s immediate reason to join.
History
1806: U Pan Hle raises teak with crops in Tharrawaddy (Myanmar)
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1856: Brandis adopts it in Burma, drawing on the German Waldfeldbau (crops in forests)
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1887: Introduced to South Africa
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1890: Brandis brings it to India (Chittagong, Bengal; also Coorg)
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1896: First taungya plantations in North Bengal
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1911–1912: Regular taungya for sal (1911) and teak (1912) in North Bengal
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1923: Adopted in Uttar Pradesh for sal
Exam point: The e-course also says taungya reached Chittagong and Sylhet in 1870; Nair gives 1890 for Chittagong and Bengal. The years 1806 (U Pan Hle), 1856 (Brandis) and 1896 (first plantations in North Bengal) are the safe ones.
Types of taungya (e-course)
| Type | How it works | Remarks |
|---|---|---|
| Departmental taungya | Forest department raises crops with daily-wage labour | Main aim is to keep down weeds; costly |
| Leased taungya | Land leased to the highest bidder for a fixed period | Bidder wants crop profit; trees may suffer |
| Village taungya | Families settled in forest villages get about 0.8–1.7 ha for 3–4 years | Most successful type; steady labour and food |
Conklin (1957) separated integral taungya (a complete, community-wide way of life) from partial taungya (mainly economic interest).
Taungya around the world
| Name | Country |
|---|---|
| Tumpangsari | Indonesia (Java) |
| Shamba | Kenya, East Africa |
| Kaingining | Philippines |
| Parcelero | Puerto Rico |
| Consorciação | Brazil |
| Kumri, Jhooming, Ponam, Taila, Tuckle | Various parts of India |
Thailand’s Forest Village Scheme (Forest Industries Organization) gave each family at least 1.6 ha with a house plot and homegarden. Kenya absorbed its shamba farmers into the civil service in 1976.
Taungya in Indian states (examples)
| State | Trees | Crops |
|---|---|---|
| Kerala | Teak, Bombax ceiba, Eucalyptus | Paddy, tapioca, ginger, turmeric |
| Assam | Sal (Shorea robusta, S. assamica) | Paddy |
| West Bengal | Teak, sal, Schima, Cryptomeria | Paddy, maize, millets, ginger, pineapple |
| Karnataka | Teak, sandal, Cassia siamea | Paddy, tapioca |
| Tamil Nadu | Teak, sandal, tamarind, Acacia nilotica | Millets, pulses, groundnut, cotton |
| Andaman and Nicobar | Pterocarpus dalbergioides | Sugarcane, maize |
Taungya vs shifting cultivation
| Point | Shifting cultivation | Taungya |
|---|---|---|
| Main aim | Food for the family | Forest plantation; food is secondary |
| Arrangement | Sequential (crop, then fallow) | Simultaneous for a short time (concomitant) |
| What ends cropping | Fall in soil fertility | Shade as the canopy closes |
| Main soil problem | Fertility decline | Erosion hazard |
| End product | Secondary forest or degraded bush | Even-aged plantation |
Advantages
- Cheap artificial regeneration of forests
- Employment for landless people
- Full use of the site in early years
- Food from forest land
- Weeds and climbers kept down by cultivation
- Highly remunerative to forest departments
Disadvantages
- Loss of soil fertility and soil exposure
- Accelerated erosion
- Danger of epidemics
- Legal problems over land
- Exploitation of human labour
4. From Nair (1993): more on shifting cultivation and taungya
The points in this section are found only in Nair’s detailed book, not in the e-course. They are useful for ICAR JRF/SRF, NET and PhD entrance papers that go beyond the syllabus.
How big is shifting cultivation? Sources differ
| Source | Area | People |
|---|---|---|
| FAO (1982), used in the e-course | About 360 Mha (30% of exploitable soils) | Over 250 million |
| Crutzen and Andreae (1990), quoted by Nair | 300–500 Mha | About 200 million |
- The traditional fallow before the farmer returns is 5–20 years.
- A land-use factor L above 10 marks the early, stable stage; L = 1 is permanent cropping, as in the compound farms of south-east Nigeria.
- In the savanna version, crops such as yam are grown on mounds about 50 cm high and the fallow is about 10 years. Weeds and erosion are worse than in the forest version.
- Burning adds bases and phosphorus and raises pH, but only for a short time. Most soils under shifting cultivation are low-activity-clay Ultisols, Oxisols and Alfisols.
More regional names (Okigbo, 1985, in Nair)
| Name | Country or region |
|---|---|
| Jumar | Java (Indonesia) |
| Tam-ray | Thailand |
| Hay | Laos |
| Coamile | Mexico |
| Proka | Ghana |
| Chitimene | Zaire, Zambia, Zimbabwe, Tanzania |
| Bewar, Dhya, Dippa, Erka, Jhum, Kumri, Penda, Podu, Pothu | India |
What a forest fallow gives back (Lundgren, 1978)
Across 18 tropical forest sites, litterfall averaged about 8–9 t/ha/yr. It carried the following nutrients back to the soil each year:
| Nutrient | kg/ha/yr in litterfall |
|---|---|
| Nitrogen (N) | 134 |
| Phosphorus (P) | 7 |
| Potassium (K) | 53 |
| Calcium (Ca) | 111 |
| Magnesium (Mg) | 32 |
Cover crops and planted fallows
- Herbaceous legume cover crops used under plantation crops: Pueraria phaseoloides, Centrosema pubescens, Calopogonium mucunoides, Mucuna spp. and Psophocarpus palustris.
- An early record: Milsum and Bunting (1928) tried shrub legumes as fallow in Malaysia.
- Young (1989) listed 31 genera and 53 species suitable as fallow trees. His first priority: Acacia auriculiformis, A. mearnsii, Faidherbia albida, Flemingia macrophylla, Leucaena leucocephala and Paraserianthes falcataria.
Taungya: points made by Nair
- Most tropical forest plantations in Asia and Africa owe their origin to taungya.
- The land stays with the forest department. The farmer is allowed to crop for only 2–3 years and gains no rights to the land, which is why critics call taungya exploitative of labour.
- Thailand’s Forest Village scheme was run by the Forest Industry Organization (FIO). Crops were maize, cassava and kenaf. Similar schemes were tried in Kenya, Gabon, Uganda, India, Nigeria and Cambodia.
- Kenya’s shamba system began in the early 1900s; in 1976 the shamba workers were absorbed into the civil service (Oduol, 1986).
- In Kerala, many taungya lands later became permanent settlements (Moench, 1991).
- Soil effects are site-specific: Alexander et al. (1980) recorded erosion under taungya in Kerala, while Ojeniyi found no harm under Gmelina taungya in Nigeria.
- Nair calls taungya “relatively unimproved”: there has been little research to improve it.
Exam point: Area and population figures for shifting cultivation differ between sources. In an exam, give the source with the figure: FAO (1982) 360 Mha and 250 million people; Crutzen and Andreae (1990) 300–500 Mha and 200 million.
5. Quick revision box
- Shifting cultivation: 360 Mha, 30% of exploitable soils, 250 million people.
- Crop 2–3 years, fallow 10–20 years (India now 2–3 years).
- L = (C + F)/C; R = C/(C + F).
- Jhum NE India; Kurwa Jharkhand; Podu Orissa/AP; Milpa Mexico; Chena Sri Lanka; Ladang Indonesia; Tavy Madagascar; Chitemene Zambia.
- Improved fallow: planted (N-fixing) trees replace natural fallow; Sesbania 165 kg N/ha in 65 days.
- Taung = hill, ya = cultivation (Burmese). U Pan Hle 1806; Brandis 1856 (Waldfeldbau).
- India: Brandis 1890; first plantations North Bengal 1896; sal 1911, teak 1912; UP 1923.
- Village taungya is most successful (0.8–1.7 ha for 3–4 years).
- Tumpangsari Indonesia; Shamba Kenya; Parcelero Puerto Rico.
- Taungya = concomitant; main soil problem is erosion.
- Nair extras: Crutzen and Andreae (1990) 300–500 Mha, 200 million people; fallow 5–20 years.
- Okigbo names: Coamile Mexico, Proka Ghana, Tam-ray Thailand, Hay Laos, Jumar Java.
- Lundgren (1978) forest litter: 8–9 t/ha/yr with 134 N, 7 P, 53 K, 111 Ca, 32 Mg kg/ha.
- Young (1989): 31 genera, 53 species of fallow trees. Forest Village (Thailand) run by FIO.
6. Interactive MCQ Quiz
23 questions. Tap an option to see the answer and explanation, then go to the next question.
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