1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)

Sustainable Management of River Oases along the Tarim River, China (SuMaRiO / GLUES)

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)

Universität Hohenheim - Germany

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

14/05/2015

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:

Yes

2.1 Short description of the Technology

Definition of the Technology:

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

2.2 Detailed description of the Technology

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 of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment

2.6 Date of implementation

If precise year is not known, indicate approximate date:

• 10-50 years ago

2.7 Introduction of the Technology

Comments (type of project, etc.):

It is not clear how the technology was invented.

3.1 Main purpose(s) of the Technology

• improve production

3.2 Current land use type(s) where the Technology is applied

Comments:

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

If land use has changed due to the implementation of the Technology, indicate land use before implementation of the Technology:

Forests / woodlands: Fn: Natural

3.3 Further information about land use

Water supply for the land on which the Technology is applied:

• full irrigation

Number of growing seasons per year:

• 1

Specify:

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

3.4 SLM group to which the Technology belongs

• improved ground/ vegetation cover
• water diversion and drainage

3.5 Spread of the Technology

Specify the spread of the Technology:

• evenly spread over an area

If the Technology is evenly spread over an area, indicate approximate area covered:

• > 10,000 km2

Comments:

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

3.6 SLM measures comprising the Technology

Comments:

Main measures: management measures

Secondary measures: agronomic measures

Type of agronomic measures: mulching

3.7 Main types of land degradation addressed by the Technology

Comments:

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 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:

• reduce land degradation

Comments:

Main goals: mitigation / reduction of land degradation

4.1 Technical drawing of the Technology

4.2 Technical specifications/ explanations of technical drawing

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 General information regarding the calculation of inputs and costs

Specify currency used for cost calculations:

• US Dollars

4.4 Establishment activities

	Activity	Type of measure	Timing
1.	Tractor
2.	Drip line installation, plastic mulch and seeding tool	Agronomic	At sowing
3.	Making holes for the (cotton) plants in the plastic mulch.Maintaining hoses	Agronomic	After emerging

4.5 Costs and inputs needed for establishment

	Specify input	Unit	Quantity	Costs per Unit	Total costs per input	% of costs borne by land users
Labour	Drip line installation	ha	1.0	3.0	3.0	100.0
Labour	Machine use	ha	1.0	5.0	5.0	100.0
Equipment	Tractor	Piece	1.0	5000.0	5000.0	100.0
Plant material	seeds	kg	30.0	3.0	90.0
Construction material	Plastic mulch		1.0	32.0	32.0	50.0
Construction material	Black dripe lines	Set	1.0	380.0	380.0	50.0
Total costs for establishment of the Technology					5510.0

Comments:

Duration of establishment phase: 0.33 month(s)

4.6 Maintenance/ recurrent activities

	Activity	Type of measure	Timing/ frequency
1.	Ploughing and leveling of field.	Agronomic	Before sowing
2.	Irrigation
3.	Removal of the drip lines and the plastic mulch

4.7 Costs and inputs needed for maintenance/ recurrent activities (per year)

	Specify input	Unit	Quantity	Costs per Unit	Total costs per input	% of costs borne by land users
Labour	Collecting mulch	ha	1.0	5.0	5.0	98.0
Fertilizers and biocides	Irrigation and flooding water		1.0	8.0	8.0	100.0
Total costs for maintenance of the Technology					13.0

Comments:

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 Climate

5.2 Topography

Indicate if the Technology is specifically applied in:

• not relevant

Comments and further specifications on topography:

Altitudinal zone: altitudes of 800 to 1300 meters

5.3 Soils

If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

Soil fertility: low - medium

Soil drainage / infiltration: medium

Soil water storage capacity: medium high

5.4 Water availability and quality

Comments and further specifications on water quality and quantity:

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 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

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 Average area of land owned or leased by land users applying the Technology

5.8 Land ownership, land use rights, and water use rights

Land ownership:

• state

Land use rights:

• communal (organized)
• leased

Water use rights:

• communal (organized)
• leased

Comments:

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

5.9 Access to services and infrastructure

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Water availability and quality

Income and costs

Socio-cultural impacts

Ecological impacts

Water cycle/ runoff

Soil

Other ecological impacts

6.2 Off-site impacts the Technology has shown

6.3 Exposure and sensitivity of the Technology to gradual climate change and climate-related extremes/ disasters (as perceived by land users)

Gradual climate change

Gradual climate change

	Season	Type of climatic change/ extreme	How does the Technology cope with it?
annual temperature		increase	well

Climate-related extremes (disasters)

Meteorological disasters

	How does the Technology cope with it?
local rainstorm	not well
local windstorm	well

Climatological disasters

	How does the Technology cope with it?
drought	well

Hydrological disasters

	How does the Technology cope with it?
general (river) flood	not well

Other climate-related consequences

Other climate-related consequences

	How does the Technology cope with it?
reduced growing period	well

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?

6.5 Adoption of the Technology

If available, quantify (no. of households and/ or area covered):

No number on households

Comments:

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 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
helps to save water thus saves costs. How can they be sustained / enhanced? It is subsidies by the government.

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
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 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view	How can they be overcome?
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 References to available publications

Title, author, year, ISBN:

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

Available from where? Costs?

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