The eruption of Mt. Pinatubo volcano caused the deposition of sand technically called lahar ranging in depth of 6-10 meters (Jose D. Rondal)

Resoiling (Pit with manure) (Philippines)

Description

Replacing the sand in the planting hole with soil for the proper nourishment of newly planted trees and for better moisture retention and storage.

The technology is used in two contrasting geological environment: 1) sand dunes formed through the action of wind, and 2) lahar flows caused by the eruption of Mt. Pinatubo volcano in 1991. Lahars are the pyroclastic materials deposited in the lowland through the action of water, usually several meters in thickness. Both landscape have the same characteristics: some climatic type characterized by long dry season (7 months), high silica content, high erodibility and low water holding capacity, hence, droughty. The total annual rainfall is about 2,000 mm which occur from May to October. Sand dunes and crop establishment (mango) is done by digging a hole usually 1 x 1 x 1 meter. The sand is replaced by true soil mixed with organic fertilizer. Planting is done at the onset of the rainy season, usually June. Frequent fertilization is done. Manual irrigation is necessary during the dry season. The fruit tree crops suitable in the area are mango and cashew. Afforestations species include Casuarina equisentifolia and Acacia auricoliformis. Gliricidia sepium which is a very valuable fuelwood thrives well also. Grasses particularly Sacharum spontaneum can spontaneously colorize the area, especially that of lahar.

Location

Location: Ilocos Norte; Pampanga, Ilocos Norte; Pampanga and Tarlac, Philippines

No. of Technology sites analysed:

Geo-reference of selected sites
  • n.a.

Spread of the Technology: evenly spread over an area (3.0 km²)

In a permanently protected area?:

Date of implementation: less than 10 years ago (recently)

Type of introduction

Classification of the Technology

Main purpose
  • improve production
  • reduce, prevent, restore land degradation
  • conserve ecosystem
  • protect a watershed/ downstream areas – in combination with other Technologies
  • preserve/ improve biodiversity
  • reduce risk of disasters
  • adapt to climate change/ extremes and its impacts
  • mitigate climate change and its impacts
  • create beneficial economic impact
  • create beneficial social impact
Land use

  • Cropland
    • Tree and shrub cropping
    Number of growing seasons per year: 2
  • Grazing land

Water supply
  • rainfed
  • mixed rainfed-irrigated
  • full irrigation
Purpose related to land degradation
  • prevent land degradation
  • reduce land degradation
  • restore/ rehabilitate severely degraded land
  • adapt to land degradation
  • not applicable
Degradation addressed
  • soil erosion by water - Wt: loss of topsoil/ surface erosion
  • soil erosion by wind - Et: loss of topsoil
  • chemical soil deterioration - Cn: fertility decline and reduced organic matter content (not caused by erosion)
SLM group
  • n.a.
SLM measures
  • agronomic measures
  • vegetative measures -

Technical drawing

Technical specifications

Establishment and maintenance: activities, inputs and costs

Calculation of inputs and costs
  • Costs are calculated:
  • Currency used for cost calculation: Peso
  • Exchange rate (to USD): 1 USD = 50.0 Peso
  • Average wage cost of hired labour per day: 3.00
Most important factors affecting the costs
Soil texture is the most crucial factor affecting costs. High labor is required in hauling filling materials to replace the sand in the planting hole. Also because of low water holding capacity, the plants have to be watered at least once a week during the dry season.
Establishment activities
  1. Digging of holes (Timing/ frequency: beginning of rainy season)
  2. Hauling of fill materials (for resoiling) (Timing/ frequency: beginning of rainy season)
  3. Transplanting of fruit tree seedlings (Timing/ frequency: beginning of rainy season)
Maintenance activities
  1. Fertilization (Timing/ frequency: every 6 months from planting /)
  2. Watering (Timing/ frequency: weekly during dry season /)

Natural environment

Average 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
  • humid
  • sub-humid
  • semi-arid
  • arid
Specifications on climate
Thermal climate class: tropics
Slope
  • 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
Altitude
  • 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.
Technology is applied in
  • convex situations
  • concave situations
  • not relevant
Soil depth
  • 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)
  • coarse/ light (sandy)
  • medium (loamy, silty)
  • fine/ heavy (clay)
Soil texture (> 20 cm below surface)
  • coarse/ light (sandy)
  • medium (loamy, silty)
  • fine/ heavy (clay)
Topsoil organic matter content
  • high (>3%)
  • medium (1-3%)
  • low (<1%)
Groundwater table
  • on surface
  • < 5 m
  • 5-50 m
  • > 50 m
Availability of surface water
  • excess
  • good
  • medium
  • poor/ none
Water quality (untreated)
  • good drinking water
  • poor drinking water (treatment required)
  • for agricultural use only (irrigation)
  • unusable
Is salinity a problem?
  • Ja
  • Nee

Occurrence of flooding
  • Ja
  • Nee
Species diversity
  • high
  • medium
  • low
Habitat diversity
  • high
  • medium
  • low

Characteristics of land users applying the Technology

Market orientation
  • subsistence (self-supply)
  • mixed (subsistence/ commercial)
  • commercial/ market
Off-farm income
  • less than 10% of all income
  • 10-50% of all income
  • > 50% of all income
Relative level of wealth
  • very poor
  • poor
  • average
  • rich
  • very rich
Level of mechanization
  • manual work
  • animal traction
  • mechanized/ motorized
Sedentary or nomadic
  • Sedentary
  • Semi-nomadic
  • Nomadic
Individuals or groups
  • individual/ household
  • groups/ community
  • cooperative
  • employee (company, government)
Gender
  • women
  • men
Age
  • children
  • youth
  • middle-aged
  • elderly
Area used per household
  • < 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
Scale
  • small-scale
  • medium-scale
  • large-scale
Land ownership
  • state
  • company
  • communal/ village
  • group
  • individual, not titled
  • individual, titled
Land use rights
  • open access (unorganized)
  • communal (organized)
  • leased
  • individual
Water use rights
  • open access (unorganized)
  • communal (organized)
  • leased
  • individual
Access to services and infrastructure

Impacts

Socio-economic impacts
Crop production
decreased
increased

fodder production
decreased
increased

fodder quality
decreased
increased

wood production
decreased
increased

farm income
decreased
increased

Socio-cultural impacts
conflict mitigation
worsened
improved

Ecological impacts
soil cover
reduced
improved

wind velocity
increased
decreased

None
None
None

Off-site impacts
reliable and stable stream flows in dry season (incl. low flows)
reduced
increased

downstream flooding (undesired)
increased
reduced

downstream siltation
increased
decreased

groundwater/ river pollution
increased
reduced

wind transported sediments
increased
reduced

Cost-benefit analysis

Benefits compared with establishment costs
Short-term returns
very negative
very positive

Long-term returns
very negative
very positive

Benefits compared with maintenance costs
Short-term returns
very negative
very positive

Long-term returns
very negative
very positive

Climate change

-

Adoption and adaptation

Percentage of land users in the area who have adopted the Technology
  • single cases/ experimental
  • 1-10%
  • 11-50%
  • > 50%
Of all those who have adopted the Technology, how many have done so without receiving material incentives?
  • 0-10%
  • 11-50%
  • 51-90%
  • 91-100%
Has the Technology been modified recently to adapt to changing conditions?
  • Ja
  • Nee
To which changing conditions?
  • climatic change/ extremes
  • changing markets
  • labour availability (e.g. due to migration)

Conclusions and lessons learnt

Strengths: land user's view
  • It allows the utilization of "useless" barren land

    How can they be sustained / enhanced? Government support like inputs/credits
Strengths: compiler’s or other key resource person’s view
  • It can make fertile-poor and degraded areas productive

    How can they be sustained / enhanced? Sustained information, education campaign (IEC)
  • It increases the water retention capacity of sandy soils.
Weaknesses/ disadvantages/ risks: land user's viewhow to overcome
  • Laborious (hauling of fill materials) Labor-sharing
  • High maintenance cost (irrigation, fertilizer)
Weaknesses/ disadvantages/ risks: compiler’s or other key resource person’s viewhow to overcome
  • Laborious (hauling of fill materials) Labor-sharing

References

Compiler
  • Unknown User
Editors
Reviewer
  • Alexandra Gavilano
Date of documentation: Sept. 25, 2013
Last update: Junie 13, 2019
Resource persons
Full description in the WOCAT database
Linked SLM data
Documentation was faciliated by
Institution Project
Key references
  • 2000 Annual Report, MMSU: Mariano Marcos State University (MMSU), Batac, Ilocos Norte
This work is licensed under Creative Commons Attribution-NonCommercial-ShareaAlike 4.0 International