left: Young apple trees in small pits,
the traditional method (Photo: Wang
Fei)
right: The progressive bench terraces
with apple trees (Photo: Wang Fei)
Progressive bench terrace
China - 树盘，逐年扩盘
Bench terraces are progressively expanded to form a fully
developed terrace system in order to reduce runoff and soil
Location: Shaanxi
erosion on medium- to high- angled loess slopes.
n Miaowan Village, the technology is mainly applied to apple tree plantations. Tree
seedlings are planted in rows every 4 m along the contour with a spacing of 2.5-3.5 m
between rows. Trees are planted in pits 40 cm diameter and 3040 cm deep. Manure
and/or fertilizer are applied and the seedlings are watered. Around each tree, soil from
the upper parts of the slope is removed and deposited below in order to extend the flat
terrain. Over 5-10 years, the terraces become enlarged around each tree and form a
terrace with the neighbouring trees along the contour, such that the slopes are
transformed into level bench terraces. The fruit trees are located in the middle of the
terrace. All the work is done manually using shovels.
The main purpose of this technology is to reduce runoff and soil erosion on the slope
and to improve soil quality and soil moisture retention. It is a sustainable land use
technology for small farmers because farmers can use their spare time to improve the
land’s condition during the growth of the trees. A major aim is to conserve water and
reduce runoff. Soil erosion in this village is very severe and the soil erosion rate before
amounted to 60-100 tonnes per hectare per year and was reduced practically to zero as
a result of building the terraces. Slope gradients are very steep (around 20-35
degrees). The main income of local farmers is from orchards.
The establishment phase thus takes 5-10 years. Afterwards maintenance inputs are
restricted to repairing the terrace walls.
Region: Miaowan Village, Xuejiagou
Watershed
Technology area: 2.55 km2
Conservation measure: structural
Stage of intervention: prevention of
land degradation
Origin: Developed through land user`s
initiative, 10-50 years ago
Land use type:
Cropland: Tree and shrub cropping
Climate: semi-arid, temperate
WOCAT database reference:
T_CHN053en
Related approach: Year-after-year
terraced land (QACHN53)
Compiled by: Wang Fei, Institute of
Soil and Water Conservation, CAS and
MWR
Date: 2011-06-14
Contact person: Fei Wang, Institute of
Soil and Water Conservation, CAS and
MWR, China. [email protected].
[email protected]
Classification
Land use problems:
- On moderate- to high-angled slopes, water loss and soil erosion are very high. Outside the protected canopy of the trees
rainsplash impact during heavy storms is very severe. The local farmers clear all the wild grasses and shrubs, such as
Korshinsk Peashrub, Artemisia scoparia, Leymus secalinus, Stipa bungeana, Lespedeza davurica etc. to reduce competition
with the fruit trees. Consequently, the soil is bare and unprotected (expert's point of view)
Land use
Climate
Degradation
Conservation measure
Tree and shrub cropping
rainfed
semi-arid
Soil erosion by water: loss of topsoil /
surface erosion
Structural: Reshaping surface (reducing slope)
Stage of intervention
Origin
Prevention
Mitigation / Reduction
Rehabilitation
Level of technical knowledge
Land users initiative: 10-50 years ago
Experiments / Research
Externally introduced
Agricultural advisor
Land user
Main causes of land degradation:
Direct causes - Natural: Heavy / extreme rainfall (intensity/amounts), other natural causes, orchards on steep slopes without
conservation measures
Indirect causes: poverty / wealth
Main technical functions:
- control of concentrated runoff: retain / trap
- reduced soil loss
Secondary technical functions:
- reduction of slope angle
Environment
Natural Environment
Average annual rainfall
(mm)
> 4000 mm
3000-4000 mm
2000-3000 mm
1500-2000 mm
1000-1500 mm
750-1000 mm
500-750 mm
250-500 mm
< 250 mm
Soil depth (cm)
0-20
20-50
50-80
80-120
>120
Altitude (m a.s.l.)
Landform
> 4000
3000-4000
2500-3000
2000-2500
1500-2000
1000-1500
500-1000
100-500
<100
Slope (%)
plateau / plains
ridges
mountain slopes
hill slopes
footslopes
valley floors
Growing season(s): 300 days(Mar - Nov), 200
days(Apr - Oct)
Soil texture: medium (loam)
Soil fertility: very low
Topsoil organic matter: low (<1%)
Soil drainage/infiltration: good
flat
gentle
moderate
rolling
hilly
steep
very steep
Soil water storage capacity: low
Ground water table: 5 - 50 m
Availability of surface water: medium, poor /
none
Water quality: good drinking water
Biodiversity: medium
Tolerant of climatic extremes: temperature increase, seasonal rainfall increase, seasonal rainfall decrease, heavy rainfall
events (intensities and amount), droughts / dry spells
Sensitive to climatic extremes: wind storms / dust storms
If sensitive, what modifications were made / are possible: The technology increases infiltration, reduces soil erosion by
water and improves soil moisture retention to reduce the negative impact of extreme drought. However, it does not protect
the soil well from wind erosion. Soil cover could be increased to protect against strong winds and reduce
Human Environment
Cropland per
household (ha)
<0.5
0.5-1
1-2
2-5
5-15
15-50
50-100
100-500
500-1,000
1,000-10,000
>10,000
Land user: Individual / household, Small scale
land users, common / average land users, men
and women
Population density: 50-100 persons/km2
Annual population growth: < 0.5%
Land ownership: state
Land use rights: individual
Water use rights: open access (unorganised)
Relative level of wealth: rich, which
represents 30% of the land users; 30% of the
total area is owned by rich land users
Importance of off-farm income: 10-50% of
all income: Only a few land users have
implemented this measure because there are
other market based activities that bring higher
returns. Sometimes farmers have enough
money to buy more fertilizer for the orchard.
Access to service and infrastructure: low:
drinking water and sanitation; moderate: health,
employment (eg off-farm), financial services;
high: education, roads & transport
Market orientation: commercial / market
Mechanization: manual labour
Livestock grazing on cropland: no
Technical drawing
i: first year: planting of fruit trees along the
contour in small pits ii: after 3-4 years: a small
terrace is built up around each tree (as the tree
grows it needs more water, which is collected
from the platform around the trees.. iii: after
5-8 years: terraces develop iv: final stage: fully
developed level bench terraces Owing to the
soil properties of loess, there is no need to
separate surface and subsoil as there is little
difference between them. Therefore, soil can
be moved directly from upper to lower parts of
the terrace without changing soil fertility.
(Wang Fei)
Implementation activities, inputs and costs
Establishment activities
- Plant the young trees with small pits.
- The soils from the upper parts of the slope is shovelled
away and deposited on the lower side of the trees
- Expand the pits into a large platform year by year.
- 3.4 years after planning the trees a level platform of 2
to 3 square meters around the trees is build.
- The platforms increase and the space between trees is
change into terrace.
Maintenance/recurrent activities
- Repair the bank of year-after-year terraced land
Establishment inputs and costs per ha
Inputs
Costs (US$) % met by land
user
Labour
6398.00
100%
TOTAL
6398.00
100.00%
Maintenance/recurrent inputs and costs per ha per year
Inputs
Costs (US$) % met by land
user
Labour
219.60
100%
TOTAL
219.60
100.00%
Remarks:
Slope is the most important factor. The steeper it is, the higher the cost. Labour was not considered as a cost before, but now
it is expensive so that some local farmers do not use this technology.
The costs are calculated assuming a local wage rate of 14.2 US$/day.
Assessment
Impacts of the Technology
Production and socio-economic benefits
increased crop yield
Production and socio-economic disadvantages
increased labour constraints
increased farm income
Socio-cultural benefits
groups
Socio-cultural disadvantages
improved situation of social and economic disadvantaged
Ecological benefits
Ecological disadvantages
reduced surface runoff
reduced soil loss
Off-site benefits
reduced downstream flooding
Off-site disadvantages
reduced river flows
Contribution to human well-being / livelihoods
The stable income from orchards improves the standard of living, and people can buy enough food and meat. The nine-year
compulsory education in China, which once had to be paid for, is now free.
Benefits /costs according to land user
Benefits compared with costs
short-term:
long-term:
Establishment
slightly positive
positive
Maintenance / recurrent
positive
positive
It is very cheap to maintain this measure. More trees could be planted on degraded land in future.
Acceptance / adoption:
0% of land user families (0 families; 85% of area) have implemented the technology with external material support. There are
no outside input to do sunch thing.
100% of land user families (65 families; 15% of area) have implemented the technology voluntary. In this area, there are many
other practices, such as reforestation, enclosure (to prevent grazing) and terrace construction.
There is moderate trend towards (growing) spontaneous adoption of the technology. Even the local farmers know the benefits
of progressive bench terraces, but with the increased labour costs, fewer people apply this technology.
Concluding statements
Strengths and
how to sustain/improve
Weaknesses and
how to overcome
Establishing the technology over a long time. Local farmers
It takes considerable time to establish and labour is more and
have enough time to do it
Show to land users that they have more expensive so that farmers are looking for paid work
time and can spread to work over many years and fit the
Subsidy for farmers using this measure.
labour into the time they have available.
It can reduce water loss and soil erosion and prevent the
degradation of land
Give subsidy to the local farmers to
reduce the sediment delivery into the downstream river.
It takes a lot of time to establish it.
It is difficult to use it,
because the people could balance the establishment costs and
work at the labour market. If they can get some subsidy from
government, they may adapt this measure.
It can increase soil moisture.
Makes people understand the
importance of conserving water with such a technology.
Higher yield and income.
Share ideas through meeting in
the field. Present this measure to more people and show them
how to apply it and promote the technology to more farmers.
Higher yield and income.
adopt this technology.
If they have time, they wish to
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