1.2 Coordonnées des personnes-ressources et des institutions impliquées dans l'évaluation et la documentation de la Technologie

Nom du ou des institutions qui ont facilité la documentation/ l'évaluation de la Technologie (si pertinent)

District Soil Conservation Office (DSCO) - Népal

Nom du ou des institutions qui ont facilité la documentation/ l'évaluation de la Technologie (si pertinent)

ICIMOD International Centre for Integrated Mountain Development (ICIMOD) - Népal

1.3 Conditions relatives à l'utilisation par WOCAT des données documentées

Quand les données ont-elles été compilées (sur le terrain)?

01/11/2003

Le compilateur et la(les) personne(s) ressource(s) acceptent les conditions relatives à l'utilisation par WOCAT des données documentées:

Oui

2.1 Courte description de la Technologie

Définition de la Technologie:

Level bench terraces with risers protected by fodder grasses, used for the irrigated production of rice, potatoes and wheat

2.2 Description détaillée de la Technologie

Description:

The level bench terrace is a traditional technology that makes irrigated crop production possible on steep, erosion prone slopes. The majority of such terraces in Nepal were constructed by hand many generations ago, but some new land - mostly already under rainfed cultivation on forward sloping terraces - is still being converted into irrigated terraces. The initial costs for the construction of the terraces are extremely high – and annual maintenance costs are considerable also. The climate is humid subtropical, slopes are steep (30%-60%) and soils generally have a sandy loam texture. Terraces are cropped by farmers who mostly have less than 0.5 ha of land each.
Two to three annual crops are grown per year starting with paddy rice during the monsoon, followed by potatoes and/or wheat.
While terrace beds are usually 2–6 m in width, to save labour they are made as wide as they can be without increasing the danger of slips/land slides. Surveying was traditionally done by eye, but now a water-tube level may be used. Risers are 0.8-1.5 m high with a small lip (20-25 cm). The slope of the riser varies from 80 to 160%, depending on the initial gradient of the hill. Stones are incorporated in the risers if available, and grass species such as bermuda grass (Cynodon dactylon) and napier (Pennisetum purpureum) may be planted for stabilisation and as cattle fodder. The risers are compacted (with hoes) to improve ponding conditions for the paddy rice. Twice per year the risers are scraped with a special tool: (1) at the time of land preparation for paddy rice the lower part of riser is sliced, but the upper part is left protected with grasses against the monsoon rains; (2) at the time of wheat planting the whole riser (including the lip) is scraped and spread as green manure on the terrace.
Terraces are flooded with water for paddy rice cultivation: a smaller amount of water is diverted into the fields for other crops. Excess water is drained to the lower terrace by openings in the lip, which are filled with rice straw in order to filter out sediments. The depth of water for rice - when flooded completely - is normally between 10 and 15 cm. Fertility is maintained by addition of farmyard manure, spreading the scraped soil from the riser, and also through sediment carried in the irrigation water. Nowadays, mineral fertilizers are also applied.

2.3 Photos de la Technologie

2.5 Pays/ région/ lieux où la Technologie a été appliquée et qui sont couverts par cette évaluation

3.1 Principal(aux) objectif(s) de la Technologie

• améliorer la production

3.2 Type(s) actuel(s) d'utilisation des terres, là où la Technologie est appliquée

Commentaires:

Major land use problems (compiler’s opinion): - steep slopes, not suitable for agriculture in their original state (better for forestry, agroforestry, horticulture, and fruit
trees)
- small and scattered plots of land
- land users find chemical fertilizers and water expensive
- there is water scarcity from September to May and too much rain in the monsoon period (June to August) with the danger of erosion and collapse of the terraces

3.3 Informations complémentaires sur l'utilisation des terres

Approvisionnement en eau des terres sur lesquelles est appliquée la Technologie:

• pluvial

Nombre de période de croissance par an: :

• 2

Précisez:

Longest growing period in days: 150 Longest growing period from month to month: Jun - Oct Second longest growing period in days: 120 Second longest growing period from month to month: Nov - Feb

3.4 Groupe de GDT auquel appartient la Technologie

• mesures en travers de la pente

3.5 Diffusion de la Technologie

Spécifiez la diffusion de la Technologie:

• répartie uniformément sur une zone

Si la Technologie est uniformément répartie sur une zone, indiquez la superficie couverte approximative:

• 0,1-1 km2

Commentaires:

Total area covered by the SLM Technology is 1 sq km2.

3.6 Mesures de GDT constituant la Technologie

Commentaires:

Main measures: agronomic measures, vegetative measures, structural measures

Type of agronomic measures: manure / compost / residues, mineral (inorganic) fertilizers

3.7 Principaux types de dégradation des terres traités par la Technologie

Commentaires:

Main type of degradation addressed: Wt: loss of topsoil / surface erosion, Wg: gully erosion / gullying, Wm: mass movements / landslides

3.8 Prévention, réduction de la dégradation ou réhabilitation des terres dégradées

Spécifiez l'objectif de la Technologie au regard de la dégradation des terres:

• prévenir la dégradation des terres

4.1 Dessin technique de la Technologie

4.2 Spécification/ explications techniques du dessin technique

Layout of irrigated terraces. Openings in the lips drain excess water, grass cover stabilises lips and risers (right). After harvesting of rice, the grass is scraped off the lower part of the risers (left) and spread on the terrace beds

Technical knowledge required for field staff / advisors: high

Technical knowledge required for land users: high

Main technical functions: reduction of slope angle, reduction of slope length, increase / maintain water stored in soil, control of dispersed and concentrated runoff, increase in soil fertility

Secondary technical functions: improvement of ground cover, water harvesting / increase water supply, water spreading

Manure / compost / residues
Material/ species: green/farmyard manure

Vegetative measure: fodder grass at risers

Terrace
Material: earth

4.3 Informations générales sur le calcul des intrants et des coûts

Spécifiez la manière dont les coûts et les intrants ont été calculés:

• par superficie de la Technologie

Indiquez la monnaie utilisée pour le calcul des coûts:

• dollars US

4.4 Activités de mise en place/ d'établissement

	Activité	Type de mesures	Calendrier
1.	Planting grasses including bermuda grass (Cynodon dactylon).	Végétale	during monsoon
2.	Construct bunds (risers) with soil from upper and lower sides	Structurel	before monsoon
3.	Level terrace beds (soil moved from upper to lower part of terraces).	Structurel	before monsoon
4.	Make lips on edges of terraces	Structurel	before monsoon
5.	Compact risers	Structurel	before monsoon
6.	Construct irrigation canal	Structurel	before monsoon
7.	Make openings in lips for drainage of excess water	Structurel	before monsoon
8.	Test-irrigate terrace for accurate levelling	Structurel	during monsoon
9.	Plant grasses including Bermuda grass (Cynodon dactylon)	Structurel	during monsoon
10.	After 2–3 years: some narrow terraces may be merged to form single, wider terraces	Structurel	during monsoon

4.6 Activités d'entretien/ récurrentes

	Activité	Type de mesures	Calendrier/ fréquence
1.	Flood the paddy fields ..	Agronomique	(June/July) / Repeated 3–4 times during
2.	Slice/scrape grass and soil on lower part of risers and spread on terraces	Agronomique	(when flooded, June/July) /
3.	Plant rice and apply mineral fertilizer	Agronomique	(June/July). /
4.	Harvest rice	Agronomique	(October) /
5.	Apply manure (cattle manure), after rice harvest	Agronomique	(October). /
6.	Slice/scrape grass and soil from whole of risers and spread on terraces; repairsmall collapses/slumps in risers	Agronomique	(October/November) /
7.	Pprepare land	Agronomique	(November) /
8.	Apply mineral fertilizer	Agronomique	(November/December). /
9.	Irrigate	Agronomique	Nov. / repeated several times during cultivation
10.	Harvest of potato/wheat	Agronomique	(January-March). /
11.	Planting of rice	Végétale	June,July /
12.	planting of potatoes, wheat	Végétale	November /
13.	Repair of small collapses/slumps in risers.	Structurel	(Oct./Nov.)/

4.7 Coûts et intrants nécessaires aux activités d'entretien/ récurrentes (par an)

	Spécifiez les intrants	Unité	Quantité	Coûts par unité	Coût total par intrant	% des coût supporté par les exploitants des terres
Main d'œuvre	Labour	ha	1,0	350,0	350,0	100,0
Equipements	Tools	ha	1,0	5,0	5,0	100,0
Engrais et biocides	Fertilizer	ha	1,0	185,0	185,0	100,0
Engrais et biocides	Compost/manure	ha	1,0	300,0	300,0	100,0
Coût total d'entretien de la Technologie					840,0

Commentaires:

Machinery/ tools: hoe, spade, baskets, (doko), special tool for scraping

Current establishment costs are very difficult to determine since the majority of the traditional terraces were
established a long time ago. Costs depend closely on the present state of the land (forward sloping terraces or uncultivated) and the need for irrigation canals. Farmers say that construction now could cost up to US$ 10,000 per ha if carried out by hand at full labour cost. The cost given for maintening the terraces (approx. US$ 840 per ha) includes all associated annual crop production costs. In this case study, 100% of the construction costs were borne by land users.

5.1 Climat

5.2 Topographie

5.3 Sols

Si disponible, joignez une description complète du sol ou précisez les informations disponibles, par ex., type de sol, pH/ acidité du sol, capacité d'échange cationique, azote, salinité, etc.

Soil fertility is medium

Soil drainage / infiltration is good because of the geology and soil texture (loam)

5.6 Caractéristiques des exploitants des terres appliquant la Technologie

Indiquez toute autre caractéristique pertinente des exploitants des terres:

Off-farm income specification: hired labour (on other farmers’ fields) or as porters

Market orientation of production system: Subsistence (rice/wheat) and commercial (potatoes)

5.7 Superficie moyenne des terres détenues ou louées par les exploitants appliquant la Technologie

5.8 Propriété foncière, droits d’utilisation des terres et de l'eau

Propriété foncière:

• individu, sans titre de propriété

Droits d’utilisation des terres:

• loué
• individuel

Commentaires:

Land use rights: leased (90% of farmers), individual (10%)

6.1 Impacts sur site que la Technologie a montrés

Impacts socio-économiques

Production

Revenus et coûts

Autres impacts socio-économiques

Impacts socioculturels

Impacts écologiques

Cycle de l'eau/ ruissellement

Sols

Réduction des risques de catastrophe et des risques climatiques

Autres impacts écologiques

6.2 Impacts hors site que la Technologie a montrés

6.3 Exposition et sensibilité de la Technologie aux changements progressifs et aux évènements extrêmes/catastrophes liés au climat (telles que perçues par les exploitants des terres)

Changements climatiques progressifs

Changements climatiques progressifs

	Saison	Type de changements/ extrêmes climatiques	Comment la Technologie fait-elle face à cela?
températures annuelles		augmente	bien

Extrêmes climatiques (catastrophes)

Catastrophes météorologiques

	Comment la Technologie fait-elle face à cela?
pluie torrentielle locale	pas bien
tempête de vent locale	pas bien

Catastrophes climatiques

	Comment la Technologie fait-elle face à cela?
sécheresse	pas bien

Catastrophes hydrologiques

	Comment la Technologie fait-elle face à cela?
inondation générale (rivière)	pas bien

Autres conséquences liées au climat

Autres conséquences liées au climat

	Comment la Technologie fait-elle face à cela?
réduction de la période de croissance	pas bien

6.4 Analyse coûts-bénéfices

Quels sont les bénéfices comparativement aux coûts de mise en place (du point de vue des exploitants des terres)?

Quels sont les bénéfices comparativement aux coûts d'entretien récurrents (du point de vue des exploitants des terres)?

6.5 Adoption de la Technologie

Parmi tous ceux qui ont adopté la Technologie, combien d'entre eux l'ont fait spontanément, à savoir sans recevoir aucune incitation matérielle ou aucun paiement?

• 90-100%

Commentaires:

100% of land user families have adopted the Technology without any external material support

6.7 Points forts/ avantages/ possibilités de la Technologie

Points forts/ avantages/ possibilités du point de vue du compilateur ou d'une autre personne ressource clé
Income and production increased How can they be sustained / enhanced? Proper management of the terraces (including all maintenance activities)
Easier to cultivate flat terraces/less labour required (after establishment of terraces)
Work sharing: traditional terraces are part of a long tradition of work sharing within the community with no external labourneeded How can they be sustained / enhanced? Prevent loss of well established traditions and norms
Technology is easy to understand/apply. Increased opportunities for irrigation facilities: farmers without level terraces are not allowed (by the irrigation committee at village level) or do not claim irrigation water
The irrigation element of this technology fosters social bonds within the community How can they be sustained / enhanced? Prevent loss of well established norms and traditions.

6.8 Faiblesses/ inconvénients/ risques de la Technologie et moyens de les surmonter

Faiblesses/ inconvénients/ risques du point de vue du compilateur ou d'une autre personne ressource clé	Comment peuvent-ils être surmontés?
Decreased grass production (grazing area reduced)	Promote planting of high value grass species on risers (such as bermuda grass).
The farmers believe that the terraces are too narrow (for efficient use of tractors); they would like to have wider terraces	Investigate possibilities of constructing wider paddy rice terraces on steep slopes, which, according to present experience, is not possible.
High labour costs for establishment.

7.2 Références des publications disponibles

Titre, auteur, année, ISBN:

There is considerable literature on the construction and maintenance of irrigated terraces in general, but no references thatspecifically describe the traditional paddy rice terraces in Nepal