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Technologies
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Integrating native trees in rubber monocultures [China]

减缓单一橡胶种植的负面环境影响:关于橡胶与当地树种混种并结合杂草管理的生态种植研究 (Chinese)

technologies_1717 - China

Completeness: 86%

1. General information

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

Key resource person(s)

SLM specialist:
SLM specialist:
SLM specialist:

Blagodatsky Sergey

University of Hohenheim

Germany

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Humboldt Universität zu Berlin (HU Berlin) - Germany
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Universität Hohenheim - Germany
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
China Agricultural University (China Agricultural University) - China

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

12/02/2016

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

Yes

1.4 Declaration on sustainability of the described Technology

Is the Technology described here problematic with regard to land degradation, so that it cannot be declared a sustainable land management technology?

No

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

The technology combines the integration of native tree species into rubber monocultures with changed weed management to mitigate negative environmental impacts and to provide alternative income options for farmers.

2.2 Detailed description of the Technology

Description:

Natural rubber is a crucial renewable resource produced from the tree Hevea brasiliensis. Production is largely based on monoculture, often associated with chemical-based clean-weeding. This causes environmental problems such as loss of biodiversity, pesticide pollution and erosion of topsoil. The SLM-technology aims at mitigating negative impacts by interplanting the rubber with native tree species which have economic potential of their own. Changes in weed management are part of the package also.

Native (indigenous) tree species are integrated into mature rubber plantations. Criteria for species selection are: a) adapted to environmental conditions; b) shade tolerant; c) vertical growth not affected by light; d) conservation value; e) economic potential; f) easy to manage. Rubber trees are usually planted in rows at a spacing of 6-8 m, and an intra-row distance of 2.5 to 3 m. The native trees are planted between the rubber rows. The plantation should be mature as the canopy will have reached its highest density, and weed competition is naturally suppressed. The spacing of the native trees needs to be adapted to their growth potential and intended usage. After planting, regular monitoring is necessary to identify pests or diseases. The following species were selected for demonstration sites: 1) Parashorea chinensis, a valuable timber tree, 2) Taxus mairei, a multi-purpose tree, providing good timber but also an anti-cancer drug, taxol, and 3) Nyssa yunnanensis, selected for its conservation value. At the end of the economic life span of the rubber trees (about 30 years) there will be several options, but there are three main ones. First the rubber plantation can be replanted, although the harvest of the Parashorea chinensis trees would be premature. The Taxus mairei trees could be maintained through a new plantation cycle. Second, both, the rubber and the intercropped trees could be maintained for future timber and taxol production. Third, the plantation could be transformed into a sustainable forest managed scheme where the rubber trees are extracted step by step and the intercropped trees maintained for their intrinsic value.

Procedures for the selection and planting of the indigenous tree species are crucial. Identification should be based on suitability for the climate and soil as well as economic potential. The raising of tree seedlings requires experience and nursery propagation by experts might be required. Only healthy seedlings should be used. Planting should take place during rainy periods. Potted seedlings are better than bare-rooted seedlings since they establish better. Generally, weed management (if necessary) should shift from herbicide application to mechanical weeding. Grass competition needs to be avoided in any case! Controlled cover of natural undergrowth will reduce erosion and promote water infiltration.

The implementation site for the trials is located in Xishuangbanna Prefecture, Yunnan Province, SW China. The original vegetation was tropical rain and monsoon forest, but now there is a rich mosaic of different land-use and vegetation types. The whole region is exceptionally species rich and part of the Indo-Burma-Biodiversity Hotspot.

2.3 Photos of the Technology

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

Country:

China

Region/ State/ Province:

Xishuangbanna Dai Autonomous Prefecture, Yunnan Province, PR China

Further specification of location:

Naban River Watershed National Nature Reserve

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • 10-50 years ago

2.7 Introduction of the Technology

  • review on available knowledge on rubber management and history
Comments (type of project, etc.):

The technology is a result of the synthesis of research findings of the SURUMER-project and a review of available publications on rubber management.

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • improve production
  • conserve ecosystem
  • preserve/ improve biodiversity

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

Cropland

Cropland

  • Tree and shrub cropping
Comments:

Major land use problems (compiler’s opinion): Large-scale expansion of rubber monocultures results in the loss of topsoil and siltation of streams with respective consequences for CO2 emissions (increased), soil degradation, water quality and stream ecology. The excessive application of agrochemicals adds to these problems. The monoculture practice combined with clean weeding results in plant biodiversity loss. The related simplification of habitat structures also leads to a considerable decline in animal biodiversity.

Major land use problems (land users’ perception): The focus of land users is primarily on sustainable income, and their environmental concerns mainly relate to water provisioning (land user's point of view). In the farmers view: “The biggest environmental problem is water quantity. Rubber sucks out a lot of water, therefore we do have a water scarcity problem”. Farmers are aware of the contamination of drinking water due to the use of pesticides and herbicides in the rubber plantations.

Future (final) land use (after implementation of SLM Technology): Mixed: Mf: Agroforestry

Type of cropping system and major crops comments: The majority of farmers shifted to pure rubber growing, although many villages still have paddy rice fields.

3.3 Further information about land use

Water supply for the land on which the Technology is applied:
  • mixed rainfed-irrigated
Number of growing seasons per year:
  • 1
Specify:

Longest growing period in days: 270, Longest growing period from month to month: April - December

3.4 SLM group to which the Technology belongs

  • agroforestry

3.5 Spread of the Technology

Comments:

Total area covered by the SLM Technology is 0.03 m2.
The technology is currently tested on three trial sites coveríng 3 ha. Some farmers started to adopt and also planted trees in rubber. But no figures are available so far.

3.6 SLM measures comprising the Technology

vegetative measures

vegetative measures

  • V1: Tree and shrub cover
management measures

management measures

  • M2: Change of management/ intensity level

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wt: loss of topsoil/ surface erosion
  • Wo: offsite degradation effects
physical soil deterioration

physical soil deterioration

  • Pk: slaking and crusting
biological degradation

biological degradation

  • Bc: reduction of vegetation cover
  • Bh: loss of habitats
  • Bs: quality and species composition/ diversity decline
water degradation

water degradation

  • Hs: change in quantity of surface water
  • Hp: decline of surface water quality
Comments:

Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (Replacement of forests by monocultures.), poverty / wealth (Older people still have the memory of extreme poverty. Rubber was the main driver to reduce poverty; high profit gained by rubber encouraged people in pursuit of large scale monoculture.), inputs and infrastructure: (roads, markets, distribution of water points, other, …) (A tremendously improved infrastructure allows the establishment of plantations even in previously remote areas.), governance / institutional (Strong support from government in terms of subsidy and other incentives from 1980s to 2000s; subsidies are more recently reduced)
Secondary causes of degradation: crop management (annual, perennial, tree/shrub) (Clear-weeding, mainly with herbicides.), disturbance of water cycle (infiltration / runoff) (Removal of natural vegetation leads to higher runoff), land tenure (Introduction of Household Responsibility System in 1980s gave use-right to farmers. This pushed decisions on transformating natural forests to monocultures. No full property rights could hinder could), labour availability (Compared to the traditional agricultural system, rubber monocultures require less labour. Recently, there is even less labour available due to the relatively low income gained by rubber), education, access to knowledge and support services (The awareness about ecosystem services and functions is still poorly developed.), war and conflicts (Chinese government´s objective to be independent on important strategic resources such as rubber)

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:
  • reduce land degradation
  • restore/ rehabilitate severely degraded land

4. Technical specifications, implementation activities, inputs, and costs

4.1 Technical drawing of the Technology

Author:

G. Langenberger, Institute of Agricultural Sciences in the Tropics (490), University of Hohenheim, Germany

4.2 Technical specifications/ explanations of technical drawing

The concept is based on the commonly suggested planting scheme of rubber with a row distance of ca. 7 m and a spacing of trees within the rows of ca. 2.5 to 3 m, resulting in ca. 450 to 500 trees/ha. The intercropping will take place between the rubber rows, on terraced slopes between the rubber terraces. Planting takes place after the plantations have reached half of their economic life span, which is ca. 15 years. It is important to consider that farmers often plant much denser than suggested by official guidelines, which needs an assessment of the light / shade conditions. With a too high rubber density the resulting light conditions might be too poor for intercropping even for forest trees. In our case the distance within a row of the intercropped trees has been set at 6 m, due to the (known) ecological characteristics of the selected 4 tree species. But the decision needs to be taken specifically for each new site, the potential tree species and the intentions of the land-user. Thus, in our case, we opted for a higher density of Taxus (bold circles) which is well known for its slow growth. and integrated the two other tree species at a wider distance (dotted circles).

Location: Yunnan Province, SW China. Xishuangbanna Prefecture
Date: September 2014

Technical knowledge required for field staff / advisors: high (The selection and management of native tree species requires a very good ecological as well as dendrological knowledge and understanding.)
Technical knowledge required for land users: moderate (If species selection has been successful and management is supported by a knowledgeable extension service.)
Main technical functions: control of dispersed runoff: retain / trap, stabilisation of soil (eg by tree roots against land slides), increase in organic matter, increase of infiltration, promotion of vegetation species and varieties (quality, eg palatable fodder)
Secondary technical functions: control of raindrop splash, improvement of surface structure (crusting, sealing), improvement of topsoil structure (compaction), increase / maintain water stored in soil, increase of groundwater level / recharge of groundwater

Aligned: -contour
Vegetative material: T : trees / shrubs
Vegetative measure: Intercropping of native tree species
Vegetative material: T : trees / shrubs
Number of plants per (ha): 240
Spacing between rows / strips / blocks (m): 7 m
Vertical interval within rows / strips / blocks (m): 6 m
Vegetative measure: Vegetative material: T : trees / shrubs
Trees/ shrubs species: Parashorea chinensis, Taxus mairei, Nyssa yunnanensis: all planted (container-planting)
Slope (which determines the spacing indicated above): 0-80%
Gradient along the rows / strips: 0%
Change of land use practices / intensity level: Shift from herbicide-based weed management to mechanical weeding with machine tools. This has not yet been implemented due lack of experience and proper tools.

4.3 General information regarding the calculation of inputs and costs

other/ national currency (specify):

RMB

Indicate exchange rate from USD to local currency (if relevant): 1 USD =:

6.3

Indicate average wage cost of hired labour per day:

16.00

4.4 Establishment activities

Activity Type of measure Timing
1. 1. Seedling acquisition and transport Vegetative before or during rainy season
2. 2. Planting of seedlings in rainy season Vegetative rainy season
3. Weed management with brush cutters. Management ? no experience

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 labour ha 1.0 80.0 80.0 100.0
Equipment machine use ha 1.0 80.0 80.0
Equipment animal traction ha 1.0 8.0 8.0 100.0
Plant material seedlings ha 1.0 2400.0 2400.0
Total costs for establishment of the Technology 2568.0
Comments:

Duration of establishment phase: 0.07 month(s)

4.6 Maintenance/ recurrent activities

Activity Type of measure Timing/ frequency
1. 1. Control of pests and diseases Vegetative monthly

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 labour ha 1.0 96.0 96.0 100.0
Total costs for maintenance of the Technology 96.0
Comments:

The costs are based on the establishment of 3 demonstration plots of ca. 1 ha each. It should be possible to considerably reduce the costs by producing seedlings on site.

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Seedling costs are by far the major cost factor. Since the selected species are very unusual and don't have a considerable market they were extremely expensive. Since Taxus is also a reputed medicinal plant, it might also have influenced the price. All other costs are actually negligible compared to the costs of the seedlings. In this case the establishment of an own nursery might considerably reduce the costs, since propagation at least of Taxus and Parashorea is easy if the seeds can be acquired.

5. Natural and human environment

5.1 Climate

Annual rainfall
  • < 250 mm
  • 251-500 mm
  • 501-750 mm
  • 751-1,000 mm
  • 1,001-1,500 mm
  • 1,501-2,000 mm
  • 2,001-3,000 mm
  • 3,001-4,000 mm
  • > 4,000 mm
Agro-climatic zone
  • sub-humid

Thermal climate class: subtropics

5.2 Topography

Slopes on average:
  • flat (0-2%)
  • gentle (3-5%)
  • moderate (6-10%)
  • rolling (11-15%)
  • hilly (16-30%)
  • steep (31-60%)
  • very steep (>60%)
Landforms:
  • plateau/plains
  • ridges
  • mountain slopes
  • hill slopes
  • footslopes
  • valley floors
Altitudinal zone:
  • 0-100 m a.s.l.
  • 101-500 m a.s.l.
  • 501-1,000 m a.s.l.
  • 1,001-1,500 m a.s.l.
  • 1,501-2,000 m a.s.l.
  • 2,001-2,500 m a.s.l.
  • 2,501-3,000 m a.s.l.
  • 3,001-4,000 m a.s.l.
  • > 4,000 m a.s.l.

5.3 Soils

Soil depth on average:
  • very shallow (0-20 cm)
  • shallow (21-50 cm)
  • moderately deep (51-80 cm)
  • deep (81-120 cm)
  • very deep (> 120 cm)
Soil texture (topsoil):
  • medium (loamy, silty)
  • fine/ heavy (clay)
Topsoil organic matter:
  • medium (1-3%)

5.4 Water availability and quality

Availability of surface water:

good

Water quality (untreated):

poor drinking water (treatment required)

5.5 Biodiversity

Species diversity:
  • high

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • commercial/ market
Off-farm income:
  • 10-50% of all income
Relative level of wealth:
  • poor
  • average
Individuals or groups:
  • individual/ household
Level of mechanization:
  • manual work
Gender:
  • men
Indicate other relevant characteristics of the land users:

Land users applying the Technology are mainly Leaders / privileged
Difference in the involvement of women and men: So far, the number of persons applying the technology is still too low to draw any meaningful conclusion.
Population density: 10-50 persons/km2
Annual population growth: < 0.5% (farmers have been well off in the past, currently they are under pressure due to the very low rubber).

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

  • < 0.5 ha
  • 0.5-1 ha
  • 1-2 ha
  • 2-5 ha
  • 5-15 ha
  • 15-50 ha
  • 50-100 ha
  • 100-500 ha
  • 500-1,000 ha
  • 1,000-10,000 ha
  • > 10,000 ha
Is this considered small-, medium- or large-scale (referring to local context)?
  • small-scale

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

Land ownership:
  • state
Land use rights:
  • individual
Comments:

Water use rights seem to be an issue.

5.9 Access to services and infrastructure

health:
  • poor
  • moderate
  • good
education:
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
markets:
  • poor
  • moderate
  • good
energy:
  • poor
  • moderate
  • good
roads and transport:
  • poor
  • moderate
  • good
drinking water and sanitation:
  • poor
  • moderate
  • good

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

wood production

decreased
increased
Comments/ specify:

considerably, but no experience

Income and costs

workload

increased
decreased
Comments/ specify:

no practical experience, yet

Socio-cultural impacts

conflict mitigation

worsened
improved

Ecological impacts

Water cycle/ runoff

water quality

decreased
increased
Comments/ specify:

less erosion

surface runoff

increased
decreased
Comments/ specify:

cf. Hongxi

Soil

soil cover

reduced
improved
Comments/ specify:

compared to clear-weeding

Biodiversity: vegetation, animals

biomass/ above ground C

decreased
increased
Comments/ specify:

cf. Xueqing

6.2 Off-site impacts the Technology has shown

downstream siltation

increased
decreased

groundwater/ river pollution

increased
reduced

buffering/ filtering capacity

reduced
improved

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 well
local windstorm not known
Climatological disasters
How does the Technology cope with it?
drought not well
Hydrological disasters
How does the Technology cope with it?
general (river) flood not known

Other climate-related consequences

Other climate-related consequences
How does the Technology cope with it?
reduced growing period not well
cold spells not well
Comments:

The above assessment is based on the fact that we are actually dealing with plants adapted to tropical conditions. Therefore, the species should be less affected by high temperatures and increasing rainfall, but might be sensitive to droughts. Nevertheless, there is no experience!

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?
Short-term returns:

negative

Long-term returns:

positive

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
Short-term returns:

positive

Long-term returns:

very positive

Comments:

The establishment costs for the demo-sites have been very high, but could be considerably reduced if adopted by more farmers. The assessment above therefore needs verification!

6.5 Adoption of the Technology

Comments:

100% of land user families have adopted the Technology with external material support
3 land user families have adopted the Technology with external material support
There is a little trend towards spontaneous adoption of the Technology. Comments on adoption trend: We experienced interest in the technology by farmers, but due to the lack of experience and the lack of affordable and accessible seedlings they are hesitant.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Additional income options.
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
The technology offers considerable long-term advantageous to farmers. It diversifies the product portfolio and good options for additional income in the future. Beyond the establishment it doesn't require much labour.

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

Weaknesses/ disadvantages/ risks in the land user’s view How can they be overcome?
High investment costs. Government subsidies.
Time until first returns can be expected. 5-10 years for taxol production
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
The technology is based on a long-term perspective and thus favours farmers who have a such an outlook. But farmers with little land usually think short-term. The current trend of rural-urban migration will support the technology since it can be easily combined with off-farm work. According to SURUMER findings off-farm income already contributes about one third of the overall household income in the rubber growing areas.
Current establishment costs are very high due to the lack of a seedling market. If the technology becomes known and popular, more nurseries will produce seedlings which will reduce costs. Alternatively, farmers might establish their individual (or community) nurseries.
The technology requires considerable knowledge about tree ecology and tree breeding. There should be extension officers at the local agricultural or forestry bureaus supporting farmers.

7. References and links

7.1 Methods/ sources of information

  • field visits, field surveys
  • interviews with land users

7.2 References to available publications

Title, author, year, ISBN:

Ahrends, A. et al. (2015) Current trends of rubber plantation expansion may threaten biodiversity and livelihoods

Available from where? Costs?

Global Environ Change, 34, 48-58.

Title, author, year, ISBN:

Langenberger, G. et al. (2016) Rubber intercropping: a viable concept for the 21st century?

Available from where? Costs?

Agrofor Syst, 1-20.

Title, author, year, ISBN:

Liu, H. et al. (2016) Impact of herbicide application on soil erosion and induced carbon loss in a rubber plantation of Southwest China

Available from where? Costs?

CATENA, 145, 180-192.

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