技术

Contour bunds for crops and forest/rangeland [尼日尔 ]

Banquettes agricoles et sylvo-pastorales (French)

technologies_1652 - 尼日尔

完整性: 78%

1. 一般信息

1.2 参与该技术评估和文件编制的资源人员和机构的联系方式

关键资源人

SLM专业人员:
SLM专业人员:

Mamadou Abdou Gaoh Sani

Programme d’Appui à l’agriculture Productive (PROMAP)

尼日尔

SLM专业人员:

Dorlöchter-Sulser Sabine

Misereor

德国

有助于对技术进行记录/评估的项目名称(如相关)
Programme d’Appui à l’agriculture Productive (GIZ / PROMAP)
有助于对技术进行记录/评估的项目名称(如相关)
Manual of Good Practices in Small Scale Irrigation in the Sahel (GIZ )
有助于对技术进行记录/评估的机构名称(如相关)
Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) - 德国
有助于对技术进行记录/评估的机构名称(如相关)
Misereor - 德国

1.3 关于使用通过WOCAT记录的数据的条件

编制者和关键资源人员接受有关使用通过WOCAT记录数据的条件。:

1.4 所述技术的可持续性声明

这里所描述的技术在土地退化方面是否存在问题,导致无法被认为是一种可持续的土地管理技术?:

2. SLM技术的说明

2.1 技术简介

技术定义:

Contour bunds, built with earth or stones, increase the amount of water available to crops and vegetation, thus contributing to the restoration of degraded land

2.2 技术的详细说明

说明:

A contour bund is a rectangular structure consisting of bunds built with earth or stone or a combination of both, which can be permeable or impermeable. The bottom bund is up to 80 m long, and the wingwalls extend up to 15 m upslope. The contour bunds are built in staggered rows along the natural contour of the land with the open end facing uphill. Patches in the same row are spaced 6 m apart, and the rows are positioned about 25 m apart, depending of the gradient of the slope. Downslope of the structure, a water collection ditch 0.50 m wide and 0.30 m deep is dug. The earth excavated from the ditch is piled up and compacted to construct the main bund. When used for growing crops, a third of the total surface area inside the contour bunds is loosened by subsoiling. The remaining two thirds of the surface are left unworked and serve as a catchment area. This doubles or triples the volume of water available to crops. Trees are planted along the main bund to stabilise the structure.
Contour bunds for forest/rangeland work as contour bunds on cropland (described above), except that the sizing is slightly different. The main bund of patches used for this purpose is up to 100 m long and the rows are spaced up to 30 m apart.

In Niger, contour bunds for forest/rangeland are used to restore land in plateau areas which have been completely degraded and denuded by severe water and wind erosion. Contour bunds for growing crops are recommended for the restoration of pediments, particularly in areas where land use pressure is high. The technique is recommended for areas with a low gradient and rainfall of less than 600 mm.
The bunds capture and retain runoff for several days. Infiltration of the water into the soil increases, and there is a gradual build-up of sediment behind the bunds, creating favourable conditions for the establishment of vegetation. Contour bunds for crops increase the area of land that can be farmed and its productivity thanks to their capacity to retain runoff and the shelter provided by trees planted along the bottom bund, which protects the crops. An advantage from the perspective of watershed development is that contour bunds constructed on plateaux areas protect areas downstream against heavy runoff.

Before constructing the contour bunds, it is essential to clarify the ownership status of the land where the measures are to be implemented and who the users will be, with a view to avoiding disputes later on.
When constructing the contour bunds, it is important to mark out the contour lines correctly and ensure that the earth is firmly compacted.
With some upkeep, stone or stone-lined contour bunds last at least 20 years. Earthen bunds do not last as long. Good vegetation cover established along the bunds increases their lifetime.

The Sahel is a region where the population has always faced a high degree of climate variability, manifested both in terms of time (unexpected dry spells can occur during the rainy season) and in terms of space (rainfall can vary greatly from one area to another). The population is mainly composed of small farmers and livestock keepers.
Over the last two decades, the effects of climate change have exacerbated the already difficult conditions. Accord¬ing to projections made by climatologists, the Sahel will experience a rise in temperatures combined with highly variable rainfall and an increase in extreme weather events.
The Soil and Water conservation and rehabilitation techniques have helped people in the Sahel to manage their ecosystems more effectively and improve their productive land. As a result, communities are better prepared to cope with environmental changes (changes in the climate, land degradation, etc.) and the im¬pact of shocks, particularly droughts.

2.3 技术照片

2.5 已应用该技术的、本评估所涵盖的国家/地区/地点

国家:

尼日尔

区域/州/省:

Niger

有关地点的进一步说明:

Regions of Tillabéri, Filingué, Ouallam, Téra and Tahoua

具体说明该技术的分布:
  • 均匀地分布在一个区域
如果不知道精确的区域,请注明大致覆盖的区域:
  • 10-100 平方千米

2.6 实施日期

如果不知道确切的年份,请说明大概的日期:
  • 10-50年前

2.7 技术介绍

详细说明该技术是如何引入的:
  • 通过项目/外部干预
注释(项目类型等):

Developed, implemented and disseminated as part of projects and programmes undertaken from the 1980s onwards to combat desertification and improve natural resource management. Implemented by GIZ (German Federal Enterprise for International Cooperation), PDRT (Projet de développement rural de Tahoua - Tahoua Rural Development Project), PASP (Projet de protection intégrée des ressources agro-sylvo-pastorales Tillabéri-Nord - Project for the Integrated Protection of Agricultural, Forest and Rangeland Resources in Tillabéri-Nord)

3. SLM技术的分类

3.1 该技术的主要目的

  • 减少、预防、恢复土地退化
  • 适应气候变化/极端天气及其影响

3.2 应用该技术的当前土地利用类型

农田

农田

  • 一年一作
  • 乔木与灌木的种植
年作 - 具体指明作物:
  • 油料作物 - 花生
  • 谷类 - 小米
  • 谷类 - 高粱
  • 豆科牧草和豆类 - 豌豆
乔木和灌木种植 - 指定作物:
  • 芒果、山竹果、番石榴
每年的生长季节数:
  • 1
具体说明:

Longest growing period in days: 120; Longest growing period from month to month: August to October

森林/林地

森林/林地

  • (半天然)天然森林/林地
(半天然)天然森林/林地:具体说明管理类型:
  • 选伐
产品和服务:
  • 木材
  • 薪材
  • 水果和坚果
  • 其它森林产品
  • 放牧/啃牧
注释:

major cash crop: Ground nut
major food crops: Millet
other: Sorghum, cow pea and mangoes

Major land use problems (compiler’s opinion): crusting, surface runoff, water and wind erosion, unadapted land use methods, rapidly growing population increasing pressure on land, reduced or abandoned fallow periods, insecure access to land

Type of cropping system and major crops comments: farmers are mainly agropastoralists with some communities specialised on pure pastoralism

Constraints of forested government-owned land or commons

Livestock density: 1-10 LU /km2

3.4 供水

该技术所应用土地的供水:
  • 雨养

3.5 该技术所属的SLM组

  • 农业林学
  • 横坡措施

3.6 包含该技术的可持续土地管理措施

植物措施

植物措施

  • V1:乔木和灌木覆盖层
结构措施

结构措施

  • S2:堤、岸
注释:

Type of vegetative measures: aligned: -contour

3.7 该技术强调的主要土地退化类型

土壤水蚀

土壤水蚀

  • Wt:表土流失/地表侵蚀
化学性土壤退化

化学性土壤退化

  • Cn:肥力下降和有机质含量下降(非侵蚀所致)
物理性土壤退化

物理性土壤退化

  • Pc:压实
  • Pk:熟化和结壳
生物性退化

生物性退化

  • Bc:植被覆盖的减少
水质恶化

水质恶化

  • Ha:干旱化
注释:

Main causes of degradation: soil management (Unadapted landuse methods, reduced or abandoned fallow periods), crop management (annual, perennial, tree/shrub) (Neglect of fallow periods and crop rotation), droughts (due to heat waves), population pressure (rapidly growing population increasing pressure on land), land tenure (insecure access to land and collectively managed common land), poverty / wealth (very poor population)

Secondary causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (deforestation through overgrazing and fire wood collection), over-exploitation of vegetation for domestic use (firewood collection), overgrazing (cattle, sheep and goats), change in temperature (Climate change: heat waves), change of seasonal rainfall (more variable onset of rain), Heavy / extreme rainfall (intensity/amounts) (more variable and intensive rains), wind storms / dust storms (frequent storms), floods (due to intensive rain storms), labour availability (some migration of men to nearby cities), education, access to knowledge and support services (high level of illiteracy)

3.8 防止、减少或恢复土地退化

具体数量名该技术与土地退化有关的目标:
  • 修复/恢复严重退化的土地

4. 技术规范、实施活动、投入和成本

4.1 该技术的技术图纸

技术规范(与技术图纸相关):

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

Main technical functions: control of dispersed runoff: retain / trap, control of dispersed runoff: impede / retard, control of concentrated runoff: retain / trap, control of concentrated runoff: impede / retard, improvement of ground cover, stabilisation of soil (eg by tree roots against land slides), increase in nutrient availability (supply, recycling,…), increase of infiltration, increase / maintain water stored in soil, water harvesting / increase water supply, sediment retention / trapping, sediment harvesting, promotion of vegetation species and varieties (quality, eg palatable fodder)
Secondary technical functions: improvement of surface structure (crusting, sealing), improvement of topsoil structure (compaction), increase in organic matter, reduction in wind speed

Aligned: -contour
Vegetative material: T : trees / shrubs
Vegetation is used for stabilisation of structures.

作者:

MDR, Niger, Recueil des fiches

4.2 有关投入和成本计算的一般信息

具体说明成本计算所用货币:
  • 美元

4.3 技术建立活动

活动 时间(季度)
1. The contour bunds are built in staggered rows along the natural contour of the land with the open end facing uphill.
2. Downslope of the structure, a water collection ditch 0.50 m wide and 0.30 m deep is dug.
3. The earth excavated from the ditch is piled up and compacted to construct the main bund
4. When used for growing crops, a third of the total surface area inside the contour bunds is loosened by subsoiling
5. Trees are planted along the main bund to stabilise the structure

4.5 维护/经常性活动

活动 时间/频率
1. Damages caused by excessive rainfall need to be repaired quickly

4.7 影响成本的最重要因素

描述影响成本的最决定性因素:

Labour: 54 man-days per ha.

Equipment: pickaxes, shovels, wheelbarrows, water-tube level.

Other costs: hire of machine for subsoiling (1 day per ha).

5. 自然和人文环境

5.1 气候

年降雨量
  • < 250毫米
  • 251-500毫米
  • 501-750毫米
  • 751-1,000毫米
  • 1,001-1,500毫米
  • 1,501-2,000毫米
  • 2,001-3,000毫米
  • 3,001-4,000毫米
  • > 4,000毫米
农业气候带
  • 半干旱

Thermal climate class: subtropics

5.2 地形

平均坡度:
  • 水平(0-2%)
  • 缓降(3-5%)
  • 平缓(6-10%)
  • 滚坡(11-15%)
  • 崎岖(16-30%)
  • 陡峭(31-60%)
  • 非常陡峭(>60%)
地形:
  • 高原/平原
  • 山脊
  • 山坡
  • 山地斜坡
  • 麓坡
  • 谷底
垂直分布带:
  • 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 土壤

平均土层深度:
  • 非常浅(0-20厘米)
  • 浅(21-50厘米)
  • 中等深度(51-80厘米)
  • 深(81-120厘米)
  • 非常深(> 120厘米)
土壤质地(表土):
  • 中粒(壤土、粉土)
  • 细粒/重质(粘土)
表土有机质:
  • 低(<1%)
如有可能,附上完整的土壤描述或具体说明可用的信息,例如土壤类型、土壤酸碱度、阳离子交换能力、氮、盐度等。:

Soil texture (topsoil): Fine to medium (sandy to clayey loams)

Soil fertility is very low - medium

Soil drainage / infiltration is poor - medium

Soil water storage capacity is low - medium

5.4 水资源可用性和质量

地下水位表:

5-50米

地表水的可用性:

中等

水质(未处理):

仅供农业使用(灌溉)

5.5 生物多样性

物种多样性:

5.6 应用该技术的土地使用者的特征

定栖或游牧:
  • 半游牧的
生产系统的市场定位:
  • 生计(自给)
  • 混合(生计/商业)
非农收入:
  • 收入的10-50%
相对财富水平:
  • 非常贫瘠
  • 贫瘠
机械化水平:
  • 手工作业
  • 畜力牵引
性别:
  • 男人
说明土地使用者的其他有关特征:

Population density: 10-50 persons/km2

Annual population growth: 3% - 4%

Off-farm income specification: men migrate temporarily or permanently to cities for off-farm income, women and men seasonally carry out paid farm work

Market orientation of production system: Most households crop for subsistence (mainly for small agropastoralists), but surplus is sold on market (medium agropastoralists). Commercial markets: some vegetable growing and pastoralists.

Level of mechanization: Ox and donkey for animal traction

5.7 应用该技术的土地使用者使用的平均土地面积

  • < 0.5 公顷
  • 0.5-1 公顷
  • 1-2 公顷
  • 2-5公顷
  • 5-15公顷
  • 15-50公顷
  • 50-100公顷
  • 100-500公顷
  • 500-1,000公顷
  • 1,000-10,000公顷
  • > 10,000公顷
这被认为是小规模、中规模还是大规模的(参照当地实际情况)?:
  • 小规模的

5.8 土地所有权、土地使用权和水使用权

土地所有权:
  • 社区/村庄
土地使用权:
  • 自由进入(无组织)
用水权:
  • 自由进入(无组织)

5.9 进入服务和基础设施的通道

健康:
  • 贫瘠
  • 适度的
教育:
  • 贫瘠
  • 适度的
技术援助:
  • 贫瘠
  • 适度的
就业(例如非农):
  • 贫瘠
  • 适度的
市场:
  • 贫瘠
  • 适度的
能源:
  • 贫瘠
  • 适度的
道路和交通:
  • 贫瘠
  • 适度的
饮用水和卫生设施:
  • 贫瘠
  • 适度的
金融服务:
  • 贫瘠
  • 适度的

6. 影响和结论性说明

6.1 该技术的现场影响

社会经济效应

生产

作物生产

降低
增加

饲料生产

降低
增加

畜牧生产

降低
增加

木材生产

降低
增加

生产故障风险

增加
降低

生产区域

降低
增加
水资源可用性和质量

灌溉用水需求

增加
降低
收入和成本

农业收入

降低
增加

社会文化影响

食品安全/自给自足

减少
改良

SLM/土地退化知识

减少
改良

livelihood and human well-being

decreased
increased
注释/具体说明:

Contour bunds for crops increase the area of land that can be farmed and its productivity thanks to their capacity to retain runoff and the shelter provided by trees planted along the bottom bund, which protects the crops

生态影响

水循环/径流

水的回收/收集

减少
改良

地表径流

增加
降低

地下水位/含水层

下降
补水
土壤

土壤水分

降低
增加

土壤覆盖层

减少
改良

土壤流失

增加
降低

土壤结壳/密封

增加
减少

土壤压实

增加
减少

养分循环/补给

降低
增加

土壤有机物/地下C

降低
增加
生物多样性:植被、动物

生物量/地上C

降低
增加

植物多样性

降低
增加
减少气候和灾害风险

风速

增加
降低

6.2 该技术的场外影响已经显现

下游洪水

增加
减少

下游淤积

增加
降低

6.3 技术对渐变气候以及与气候相关的极端情况/灾害的暴露和敏感性(土地使用者认为的极端情况/灾害)

渐变气候

渐变气候
季节 增加或减少 该技术是如何应对的?
年温度 增加

气候有关的极端情况(灾害)

气象灾害
该技术是如何应对的?
局地暴雨 不好
局地风暴
气候灾害
该技术是如何应对的?
干旱
水文灾害
该技术是如何应对的?
比较和缓的(河道)洪水 不好

其他气候相关的后果

其他气候相关的后果
该技术是如何应对的?
缩短生长期 未知
注释:

Physical structures can be biologically stabilized through planting of grass, bushes or trees. Damages are generally small but need to be repaired quickly.

6.4 成本效益分析

技术收益与技术建立成本相比如何(从土地使用者的角度看)?
短期回报:

积极

长期回报:

积极

技术收益与技术维护成本/经常性成本相比如何(从土地使用者的角度看)?
短期回报:

积极

长期回报:

积极

6.5 技术采用

在所有采用这项技术的人当中,有多少人是自发的,即未获得任何物质奖励/付款?:
  • 11-50%
注释:

The techniques were implemented with food for work in the 1990s to 2000. At the end, the work provided by land users was not compensated. Only small equipment and transportation were provided for free.

50% of land user families have adopted the Technology without any external material support

There is a little trend towards spontaneous adoption of the Technology

Some adoption (without support by the project) has been observed in some places. The level of replication is however limited to locations where stones are available nearby. Otherwise transportation becomes a problem. Potential for replication depends on the type of terrain, there being a nearby supply of the materials needed (stone). Subsoiling needs mechanical treatment by tractor.

6.7 该技术的优点/长处/机会

土地使用者眼中的长处/优势/机会
Contour bunds for crops increase the area of land that can be farmed and its productivity thanks to their capacity to retain runoff and the shelter provided by trees planted along the bottom bund, which protects the crops.
编制者或其他关键资源人员认为的长处/优势/机会
In a low-rainfall scenario, the construction of contour bunds helps to restore vegetation cover on vast areas of denuded land from the first year after they are established. Infiltration of the water into the soil increases, and there is a gradual build-up of sediment behind the bunds, creating favourable conditions for the establishment of vegetation.
Good vegetation cover established along the bunds con- tributes to lowering soil temperature and providing pro- tection from wind erosion along the entire length of the patch.
The construction of contour bunds upstream of river basins reduces the risk of gully erosion and siltation downstream.
In Niger, it is mainly women who have benefitted from efforts to rehabilitate land on the plateaux. With the support of development projects, women were able to secure five-year leases from land owners.
This technique transforms unproductive land into land that is economically valuable.

6.8 技术的弱点/缺点/风险及其克服方法

土地使用者认为的弱点/缺点/风险 如何克服它们?
There are also disadvantages associated with subsoiling in the contour bunds. Although subsoiling permits rapid, relatively deep infiltration, the water is situated below the level where the roots of young crops or grasses are growing, which means that the infiltrated water is not used optimally in the initial stages. Furthermore, the surface of the subsoiled land becomes hard again after several years of cultivation, because the soil structure is broken down owing to a concentration of fine particles of earth in the grooves of the subsoil, which can clog up the pores of the soil.
编制者或其他关键资源人员认为的弱点/缺点/风险 如何克服它们?
Patches with impermeable bunds are not appropriate when there are heavy rains, as the flow of water can destroy the bunds. The extensive work required to construct the contour bunds means that the community must be strongly motivated and well organised.
Contour bunds for growing crops can be used to restore land that has become unproductive. This technique is not, however, very cost-effective, because of the scale of the work involved. When constructing the contour bunds, it is important to mark out the contour lines correctly and ensure that the earth is firmly compacted.
The distribution of water in the contour bunds is often uneven, because the terrain is not level, which means that production varies considerably from one area to another
When there is heavy rain, runoff accumulates at the lowest point of the collection ditch, which can sometimes cause rilling
There is a risk of the patches becoming waterlogged, which can damage the crops

7. 参考和链接

7.1 信息的方法/来源

  • 实地考察、实地调查
  • 与土地使用者的访谈
(现场)数据是什么时候汇编的?:

01/07/2012

7.2 参考可用出版物

标题、作者、年份、ISBN:

Good Practices in Soil and Water Conservation. A contribution to adaptation and farmers´ resilience towards climate change in the Sahel. Published by GIZ in 2012.

可以从哪里获得?成本如何?

http://agriwaterpedia.info/wiki/Main_Page

模块