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)

Universität Hohenheim - Allemagne

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

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

14/05/2015

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:

Drip irrigation under plastic mulch, associated with drainage, to reduce water demand and improve cotton yields in Xinjiang Province, China.

2.2 Description détaillée de la Technologie

Description:

The dry climate and the long hours of sunshine make Xinjiang especially suitable for production of high quality cotton, and as a result some 40% of China’s cotton is grown here. But there are two main problems: shortage of water and salinization of the soil. Farmers who use the traditional flood irrigation method, and don’t have a drainage system, tend to abandon their fields when they become too saline - and then they look for new land to cultivate. A combination of mulching and drip irrigation can be very effective but still needs careful management. Drip irrigation helps to save water for farmers - and for the environment. But it is still very important to install a drainage system to dispose of surplus water in order to reduce the risk of salinization of the soils. Every four cotton rows are covered with transparent polyethylene film and as a result approximately 80% of the ground surface is covered by the plastic mulch. Plastic mulch and drip lines are placed with a specially equipped tractor.

Purpose of the Technology: Low temperatures and dry soil at sowing, in combination with soil salinity, hinder early plant growth. Plastic mulching increases soil temperature, reduces the need for irrigation, and also helps control salinity in the root zone and suppresses weeds, thereby increasing yields by 10–30% (and improving quality also) (Wang, R. et al., 2011). In the first stages after sowing the climate is particularly cold. With plastic mulching the cotton plants can be sown earlier, because the soil will not cool down during the night as much as without plastic mulch.

Establishment / maintenance activities and inputs: For the establishment of the new technology of drip irrigation under plastic mulch, it is simultaneously essential to install a drainage system to avoid raising the groundwater level and causing salinity. For the installation of the drip lines, the transparent plastic film and the seeding, a tractor and a special tool for the installationis needed: one acre can be installed in a day. After the emerging of the cotton plants, holes must be cut in the plastic film so that the cotton plants can emerge. After harvesting, the drip lines and the plastic film must be collected and recycled. If the plastic is left behind it will pollute the soils and injure livestock if they eat it. Furthermore plastic residues in the soil can reduce subsequent yields, as roots are physically inhibited. After the collection of the plastic residues, if there is no adequate drainage system, the field needs to be flooded to flush the salt layer, which has accumulated below the root zone, deeper into the soil. If the field is not flooded the salt will negatively affect the next years’ cotton plantation.

Natural / human environment: Southern Xinjiang is an arid region with 50 to 90 mm per year. Most precipitation occurs between June and August. It is classified as a temperate cold desert climate. For drip irrigation under plastic mulch, it is principally surface water that is used, which is delivered to the field via channels from reservoirs to the fields. The reservoirs are filled in summer with the floods along the Tarim River. The untreated surface water is of poor quality - for agricultural use only. For drip irrigation, the water needs to be treated to avoid blocking the drip outlets. The overall technology is expensive, and only land user groups and communities can afford the machines and the materials.

2.3 Photos de la Technologie

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

2.6 Date de mise en œuvre de la Technologie

Si l'année précise est inconnue, indiquez la date approximative: :

• il y a entre 10-50 ans

2.7 Introduction de la Technologie

Commentaires (type de projet, etc.) :

It is not clear how the technology was invented.

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): Water use conflicts between agriculture and natural vegetation, soil salinization, desertification.

Major land use problems (land users’ perception): Soil salinization and water shortage.

Future (final) land use (after implementation of SLM Technology): Cropland: Ca: Annual cropping

Livestock is grazing on crop residues

Constraints of wastelands / deserts / glaciers / swamps: water availability, evaporation

Si l'utilisation des terres a changé en raison de la mise en œuvre de la Technologie, indiquez l'utilisation des terres avant la mise en œuvre de la Technologie:

Forests / woodlands: Fn: Natural

3.3 Informations complémentaires sur l'utilisation des terres

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

• pleine irrigation

Nombre de période de croissance par an: :

• 1

Précisez:

Longest growing period in days: 220Longest growing period from month to month: March to October with irrigation

3.4 Groupe de GDT auquel appartient la Technologie

• Amélioration de la couverture végétale/ du sol
• dérivation et drainage de l'eau

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:

• > 10 000 km2

Commentaires:

It might be used also in other provinces. But this not known to the author.

3.6 Mesures de GDT constituant la Technologie

Commentaires:

Main measures: management measures

Secondary measures: agronomic measures

Type of agronomic measures: mulching

3.7 Principaux types de dégradation des terres traités par la Technologie

Commentaires:

Main type of degradation addressed: Cs: salinisation / alkalinisation, Ha: aridification

Secondary types of degradation addressed: Pw: waterlogging

Main causes of degradation: soil management (Most fields have no drainage - Increase of groundwater - salinization of soils), crop management (annual, perennial, tree/shrub) (cotton monoculture), deforestation / removal of natural vegetation (incl. forest fires) (Deforestation to gain new arable land), over abstraction / excessive withdrawal of water (for irrigation, industry, etc.), wind storms / dust storms (Dust storms, blow out of top soil), droughts (It is an arid climate), population pressure (Doubling of population during the last thirty years.), land tenure (Land belongs to the state), poverty / wealth (Family farmers are poorer than city dwellers), education, access to knowledge and support services (Poorer farmers have less access to extension services.)

Secondary causes of degradation: industrial activities and mining (There is oil production in the region, but it was not studied), discharges (point contamination of water) (Non-point source pollution and drainage water discharge from the fields.), disturbance of water cycle (infiltration / runoff) (use of surface and ground water for large scale irrigation), floods (Floods are necessary for the region (riparian forests))

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:

• réduire la dégradation des terres

Commentaires:

Main goals: mitigation / reduction of land degradation

4.1 Dessin technique de la Technologie

4.2 Spécification/ explications techniques du dessin technique

There are double rows of cotton 20 cm apart, with a drip line between. 40 cm then separates each double row. Two double rows are covered by one length of plastic mulch. There is a small strip of bare soil between each length of plastic mulch. Mulch covers around 80% of the soil surface.

Location: Korla City. Xinjiang Province / China

Technical knowledge required for field staff / advisors: moderate (For the easy and fast installation a tractor is needed)

Technical knowledge required for land users: moderate

Main technical functions: improvement of ground cover, increase of biomass (quantity), increase of water use efficiency

Secondary technical functions: improvement of surface structure (crusting, sealing), increase / maintain water stored in soil

Mulching
Material/ species: transparent plastic (Polyethylene), thickness: 0.08 mm
Quantity/ density: 7100 m/ha
Remarks: 1.4 m width in lines with spacing of 20 cm between lines

Change of land use practices / intensity level: Change from flood irrigation to drip irrigation

Major change in timing of activities: Plastic mulch enables early sowing of cotton

4.3 Informations générales sur le calcul des intrants et des coûts

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.	Tractor
2.	Drip line installation, plastic mulch and seeding tool	Agronomique	At sowing
3.	Making holes for the (cotton) plants in the plastic mulch.Maintaining hoses	Agronomique	After emerging

4.5 Coûts et intrants nécessaires à la mise en place

	Spécifiez les intrants	Unité	Quantité	Coûts par unité	Coût total par intrant	% des coût supporté par les exploitants des terres
Main d'œuvre	Drip line installation	ha	1,0	3,0	3,0	100,0
Main d'œuvre	Machine use	ha	1,0	5,0	5,0	100,0
Equipements	Tractor	Piece	1,0	5000,0	5000,0	100,0
Matériel végétal	seeds	kg	30,0	3,0	90,0
Matériaux de construction	Plastic mulch		1,0	32,0	32,0	50,0
Matériaux de construction	Black dripe lines	Set	1,0	380,0	380,0	50,0
Coût total de mise en place de la Technologie					5510,0

Commentaires:

Duration of establishment phase: 0.33 month(s)

4.6 Activités d'entretien/ récurrentes

	Activité	Type de mesures	Calendrier/ fréquence
1.	Ploughing and leveling of field.	Agronomique	Before sowing
2.	Irrigation
3.	Removal of the drip lines and the plastic mulch

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	Collecting mulch	ha	1,0	5,0	5,0	98,0
Engrais et biocides	Irrigation and flooding water		1,0	8,0	8,0	100,0
Coût total d'entretien de la Technologie					13,0

Commentaires:

Machinery/ tools: tractor with installation tool for the drip irrigation under plastic mulch, other tools: hoe

The costs for the machine, the plastic hoses and the plastic mulch are calculated above are for 1 ha and were calculated on the basis of 2013 (subsequently costs have risen). Water price: 0.019 CNY/m3. Farmers need 3000 m3 per ha.

5.1 Climat

5.2 Topographie

Indiquez si la Technologie est spécifiquement appliquée dans des:

• non pertinent

Commentaires et précisions supplémentaires sur la topographie:

Altitudinal zone: altitudes of 800 to 1300 meters

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: low - medium

Soil drainage / infiltration: medium

Soil water storage capacity: medium high

5.4 Disponibilité et qualité de l'eau

Commentaires et précisions supplémentaires sur la qualité et la quantité d'eau:

Ground water table: also < 5 m and the installation of drip irrigation under plastic mulch should be installed with a drainage system. If the groundwater table is too high salinisation of the soil will be the result

Availability of surface water: For the drip irrigation under plastic mulch mostly surface water is used. It is diverted by channels to the agricultural fields. There must be a good water availability at the fields.

Water quality (untreated): For the drip irrigation under plastic mulch the water quality must be quite high, otherwise the small holes of the drip lines will be blocked soon.

5.6 Caractéristiques des exploitants des terres appliquant la Technologie

Indiquez toute autre caractéristique pertinente des exploitants des terres:

Land users applying the Technology are mainly common / average land users

Difference in the involvement of women and men: Man are doing the earth works in the fields, women do more the harvesting

Population density: 10-50 persons/km2

Annual population growth: > 4%; 7%

5% of the land users are very rich and own 10% of the land (income from large fields of cash crops).
20% of the land users are rich and own 30% of the land (income from cash crops (fruits, cotton)).
40% of the land users are average wealthy and own 30% of the land (income from cash crops (fruits, cotton)).
30% of the land users are poor and own 20% of the land.
5% of the land users are poor and own 10% of the land.

Off-farm income specification: Farmers who have not implemented the drip irrigation under plastic mulch also generate off-farm income.

Manual labour: harvesting

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:

• état

Droits d’utilisation des terres:

• communautaire (organisé)
• loué

Droits d’utilisation de l’eau:

• communautaire (organisé)
• loué

Commentaires:

All the land belongs to the state. Farmers have the right to use the land for 70 years.

5.9 Accès aux services et aux infrastructures

6.1 Impacts sur site que la Technologie a montrés

Impacts socio-économiques

Production

Disponibilité et qualité de l'eau

Revenus et coûts

Impacts socioculturels

Impacts écologiques

Cycle de l'eau/ ruissellement

Sols

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	bien

Catastrophes climatiques

	Comment la Technologie fait-elle face à cela?
sécheresse	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	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

Si disponible, quantifiez (nombre de ménages et/ou superficie couverte):

No number on households

Commentaires:

100% of land user families have adopted the Technology with external material support

Comments on acceptance with external material support: The government gives subsidies to the farmers who are installing the drip irrigation under plastic mulch.

There is a little trend towards spontaneous adoption of the Technology

Comments on adoption trend: The government want to spread the technology in the whole region by giving subsidies to the farmers.

6.7 Points forts/ avantages/ possibilités de la Technologie

Points forts/ avantages/ possibilités du point de vue de l'exploitant des terres
helps to save water thus saves costs. How can they be sustained / enhanced? It is subsidies by the government.

Points forts/ avantages/ possibilités du point de vue du compilateur ou d'une autre personne ressource clé
It helps to save water during the vegetation period and thus helps to reduce the conflicts between the upstream and downstream farmers. How can they be sustained / enhanced? The technology (drip + mulch) needs to be supplemented by installing a drainage system in the fields otherwise there will be a build-up of salinity and farmers will abandon land and move on.

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?
Salinization of the soils is increasing The consequence is that the fields are flooded after harvest in November/December to leach out the salt. The water used for drip irrigation plus the water to flush the salts to lower soil layers add up to almost the same amount as if farmers were using the original flood irrigation technology.	drainage system in the fields required.

7.2 Références des publications disponibles

Titre, auteur, année, ISBN:

Zia-Khan,S., Spreer, W., et al. Effect of dust deposition on stomatal conductance and leaf temperature of cotton in Northwest China.

Disponible à partir d'où? Coût?

Water 2015, 7, 116-131; doi: 10.3390/w7010116. www.mdpi.com/journal/water open access.