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

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

Bureau of Soils and Water Management (Bureau of Soils and Water Management) - Philippines

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

International Centre for Research in Agroforestry (ICRAF) - Kenya

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

26/06/1999

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

1.5 Reference to Questionnaire(s) on SLM Approaches

2.1 Short description of the Technology

Definition of the Technology:

Within individual cropland plots, strips of land are marked out on the contour and left unploughed in order to form permanent, cross-slope barriers of naturally established grasses and herbs.

2.2 Detailed description of the Technology

Description:

Natural vegetative strips (NVS) are narrow live barriers comprising naturally occurring grasses and herbs. Contour lines are laid out with an A-frame or through the ‘cow's back method’ (a cow is used to walk across the slope: it tends to follow the contour and this is confirmed when its back is seen to be level). The contours are then pegged to serve as an initial guide to ploughing. The 0.3-0.5 m wide strips are left unploughed to allow vegetation to establish. Runoff flowing down the slope during intense rain is slowed, and infiltrates when it reaches the vegetative strips. Eroded soil collects on and above the strips and natural terraces form over time. This levelling is assisted by ploughing along the contour between the NVS - through ‘tillage erosion’ - which also moves soil downslope.
The vegetation on the established NVS needs to be cut back to a height of 5-10 cm: once before planting a crop, and once or twice during the cropping period. The cut material can be incorporated during land preparation, applied to the cropping area as mulch, or used as fodder. This depends on whether the farmer has livestock or not, on personal preference, and on the time of cutting. If the grass is applied as mulch or incorporated, the technology can be considered to be an agronomic, as well as a vegetative, measure.
NVS constitutes a low-cost technique because no planting material is required and only minimal labour is necessary for establishment and maintenance. Some farmers had already practiced the technology for several years before the intervention of the ICRAF (The World Agroforestry Centre) in 1993. ICRAF came to realise that farmers here preferred NVS to the recommended ‘contour barrier hedgerows’ of multipurpose trees- which land users viewed as being too labour intensive. When farmers became organised into ‘Landcare’ groups, NVS began to gain wide acceptance.
Land users appreciate the technique because it effectively controls soil erosion and prevents loss (through surface runoff) of fertilizers applied to the crop. As an option, some farmers plant fruit and timber trees, bananas or pineapples on or above the NVS. This may be during establishment of the contour lines, or later. The trees and other cash perennials provide an additional source of income, at the cost of some shading of the adjacent annual crops.

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

Indicate year of implementation:

1993

If precise year is not known, indicate approximate date:

• less than 10 years ago (recently)

2.7 Introduction of the Technology

Specify how the Technology was introduced:

• through projects/ external interventions

Comments (type of project, etc.):

It evolved in the area with some adaptations.

3.1 Main purpose(s) of the Technology

• reduce, prevent, restore land degradation

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

Comments:

Major land use problems (compiler’s opinion): Loss of topsoil through sheet erosion and rills, leading to rapid soil fertility decline. In turn soil fertility decline results in the need for increasing levels of fertilizer inputs to maintain crop yield. However, these fertilizers are often washed away by surface runoff - a vicious circle.
Major land use problems (land users’ perception): Soil productivity decline; need more inputs to maintain crop yield.

3.3 Further information about land use

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

• rainfed

Number of growing seasons per year:

• 2

Specify:

Longest growing period: 240 days (Mar - Dec)

3.4 SLM group to which the Technology belongs

• cross-slope measure

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:

• 100-1,000 km2

Comments:

Total area covered by the SLM Technology is 110 m2. The technology has been practiced by a few farmers for the past several years. With the entry of the International Centre for Research in Agroforestry (ICRAF) in 1993; farmers became organized and the technology gained wide adherence.

3.6 SLM measures comprising the Technology

Comments:

Type of agronomic measures: mixed cropping / intercropping, mulching, legume inter-planting, manure / compost / residues, contour tillage
Type of vegetative measures: aligned: -contour

3.7 Main types of land degradation addressed by the Technology

Comments:

Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (caused massive erosion and loss of productivity), Lack of enforcement of legislat./authority (no clear cut policy and support from LGU). Secondary causes of degradation: overgrazing (over population of livestock, low land ratio), education, access to knowledge and support services (farmers are not fully aware of simple SWC approach), Agricultural causes (unsustainable practice in farming)

3.8 Prevention, reduction, or restoration of land degradation

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

• reduce land degradation

Comments:

Secondary goals: prevention of land degradation, rehabilitation / reclamation of denuded land

4.1 Technical drawing of the Technology

4.2 Technical specifications/ explanations of technical drawing

A - Spacing of natural vegetative strips depends on the slope.
B - The insert shows the evolution of terraces over time through tillage and soil erosion, leading to accumulation of sediment behind the strips (steps 1-3).

Technical knowledge required for field staff / advisors: moderate. Technical knowledge required for land users: moderate.

Main technical functions: reduction of slope angle, reduction of slope length, control of dispersed runoff. Secondary technical functions: improvement of ground cover, increase of infiltration, increase in soil fertility

Agronomic measures:
Mixed cropping / intercropping - Material/ species: annuals/perennials; Remarks: laid out alternately.
Mulching - Material/ species: crop residues; spread on the surface
Legume inter-planting - purpose: for nitrogen fixation
Manure / compost / residues - Material/ species: animal, crop residues
Contour tillage - Material/ species: Contour strips are laid into 6-10 meters apart depending on slope gradient.

Vegetative measures:
Aligned, along contour
Vegetative material: T : trees / shrubs, F : fruit trees / shrubs, C : perennial crops, G : grass, O : other
Vertical interval between rows / strips / blocks (m): 1
Spacing between rows / strips / blocks (m): 5
Vertical interval within rows / strips / blocks (m): 8
Width within rows / strips / blocks (m): 0.5

Narrow grass barriers
Vegetative material: grass
Number of plants per (ha): dense grass
Width within rows / strips / blocks (m): 0.5-0.7

Trees/ shrubs species: Acacia mangium, Eucalyptus deglupta, Gmelina arbarea
Fruit trees / shrubs species: Mango, Durian, Rambutan, Jackfruit
Perennial crops species: Coffee, rubber, pineappe
Grass species: Bamboo, setara, napier, Panicum spp.
Other species: Legumes

Slope (which determines the spacing indicated above): 30%
If the original slope has changed as a result of the Technology, the slope today is (see figure below): 2%
Gradient along the rows / strips: 20%

4.3 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:

• per Technology area

Specify currency used for cost calculations:

• US Dollars

4.4 Establishment activities

	Activity	Type of measure	Timing
1.	Layout of contours with the use of an A-frame (or cow’s back method, see Annexe T3)) placing wooden pegs along the contours.	Vegetative	dry season/before land preparation
2.	Seeding (T, F, C)	Vegetative	dry season
3.	Transplanting	Vegetative	onset of rainy season
4.	Land preparation	Vegetative	dry season/before planting

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		1.0	15.0	15.0	100.0
Equipment	animal traction		1.0	40.0	40.0	100.0
Equipment	tools		1.0	25.0	25.0	100.0
Equipment	stakes (pegs)		1.0	4.0	4.0	100.0
Total costs for establishment of the Technology					84.0

Comments:

Duration of establishment phase: 12 month(s)

4.6 Maintenance/ recurrent activities

	Activity	Type of measure	Timing/ frequency
1.	Initial ploughing along the contour: leaving unploughed strips.	Agronomic	onset of rainy season / before each season
2.	Planting	Agronomic	onset of rainy season / each cropping season
3.	Mulching	Agronomic	dry season / only whensufficient crop residues
4.	Fertilization	Agronomic	early vegetative stage / each cropping season
5.	Interim cultivation/weeding	Agronomic	vegetative stage / each cropping season
6.	Ploughing mulch into the soil during normal land cultivation.	Agronomic
7.	Weeding (T, F, C), Slashing grass	Vegetative	rainy season /2 times
8.	Spreading the cut materials evenly in the alleys (between strips) as	Vegetative	rainy season /2 times (weeded materials)
9.	Pruning	Vegetative	before and during cropping /2 times per cropping

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		1.0	36.0	36.0	100.0
Equipment	animal traction		1.0	40.0	40.0	100.0
Equipment	tools		1.0	2.0	2.0	100.0
Total costs for maintenance of the Technology					78.0

Comments:

Machinery/ tools: plough, harrow

Costs of establishing contours and maintenance by slashing are calculated by total length of NVS. This example is from a typical field with an 18% slope: at an NVS spacing of 5 m, the approximate total linear distance for one hectare is 2,000 m. In this example, the farmer has paid for everything him/herself (see section on acceptance/adoption). Note that the establishment cost is more or less equivalent to the cost of standard land preparation by ploughing. When 'enrichment planting’ of the strips is carried out, extra cost for seedlings (of fruit trees for example) and associated labour for planting are incurred.

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Slope is the dominant factor in cost calculation. The steeper the slope, the more difficult the mobility is and the more closely-spaced the contours are .

5.1 Climate

5.2 Topography

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.

Soils are developed from fine-grained igeneous rocks. Soil fertility: strongly acid and with high P fixing capacity. Rapid organic matter mineralisation due to high temperature. Soil drainage is generally good except in isolated depressions.

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

Population density: 50-100 persons/km2; Annual population growth: > 4%

and own 20% of the land (5).
and own 40% of the land (30).
and own 30% of the land (65).

Off-farm income specification: Carpentry, trade, business, labour for neighbouring farms and other labour intensive agricultural activities (e.g. vegetable production)
Market orientation of production system: Upland rice is grown as subsistence. Maize is sold to feed millers.
Level of mechanization: The terrain limits the extensive use of machineries.

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:

• individual, not titled
• individual, titled

Land use rights:

• leased
• individual

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Income and costs

Other socio-economic impacts

Socio-cultural impacts

Ecological impacts

Water cycle/ runoff

Soil

Biodiversity: vegetation, animals

Climate and disaster risk reduction

Other ecological impacts

6.2 Off-site impacts the Technology has shown

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

Of all those who have adopted the Technology, how many have did so spontaneously, i.e. without receiving any material incentives/ payments?

• 50-90%

Comments:

50% of land user families have adopted the Technology with external material support (2000 families)
50% of land user families have adopted the Technology spontaneously (without external material support) (2000 families)

There is a strong trend towards spontaneous adoption of the Technology. Factor that helped was the formation of Landcare associations which have benefited their members in various ways. There is a strong trend towards spontaneous adoption, especially where Landcare associations are in operation.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Easy to establish and maintain
Improve soil fertility
Prevent soil erosion

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Easy to establish and maintain (How to sustain: Transform farmers associations into cooperative which serve as conduits in marketing. Intensify information and education campaign.)
Less competition for space, sunlight, moisture and nutrient. (How to sustain: Ensure continued regular trimming of vegetative strips and use of these as fodder or mulch.)
Low labor and external inputs requirement
Effective in reducing soil erosion (by 90%) (How to sustain: Adopt other supportive technologies like mulching, zero tillage/minimum tillage, etc.)

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 initial establishment cost	Subsidy/assistance from government
Effect of technology is not readily seen	Education about what long term sustainability means
High gestation period for some component of the system	Proper mix of annual and perennial crops

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view	How can they be overcome?
Effect on yield and income is not readily felt, since reduced erosion is not easily translated into increased income or yield	Farmers should have supplementary sources of income (eg livestock). Education about what long-term sustainability means.
Reduction of productive area by approx 10%	Optimum fertilization to offset production loss. Nutrients are conserved under NVS and this will result in the reduction of fertilizer requirement after some years.
Creation of a fertility gradient within the alley (soil is lost from the top of the alley and accumulates above the NVS where fertility then concentrates)	Increased application of fertilizer on the upper part of alley.
Overall increase of production value is low	Land users could ask for subsidy/assistance from Government: eg for fertilizers, establishment of nurseries, free seedlings (for higher value fruit trees).

7.2 References to available publications

Title, author, year, ISBN:

Managing soil fertility on terraces forming behind vegetative filter strips: An assessment of farmer strategies

Available from where? Costs?

ICRAF, P.O. Box 161, Bogor, INDONESIA

Title, author, year, ISBN:

Crop productivity using forage legumes and grasses as contour hedgerows species in an acid upland soils

Available from where? Costs?

ICRAF, P.O. Box 161, Bogor, INDONESIA

Title, author, year, ISBN:

Garrity DP, Stark M and Mercado Jr A: Natural Vegetative Strips: a bioengineering innovation to help transform smallholderconservation. pp 263–270. 2004.

Title, author, year, ISBN:

in Barker DH, Watson AJ, Sombatpanit S, Northcutt B and Maglinao AR Ground and Water Bioengineering for ErosionControl and Slope Stabilisation.

Available from where? Costs?

Science Publishers inc. Enfield, USA

Title, author, year, ISBN:

Stark M, Itumay J and Nulla S Assessment of Natural VegetativeContour Strips for Soil Conservation on Shallow Calcareous Soil in the Central Philippines.. 2003.

Available from where? Costs?

World Agroforestry Centre (ICRAF), Nairobi, Kenya