Overview of improved terraces with soil and water conservation (SWC) grasses on riser margins. Maize was the major crop before the terraces were improved. Now vegetables and rice are grown. (K.M. Sthapit)

Improved terraces (尼泊尔)

GARA SUDHAR- Nepali

描述

Hillside forward-sloping terracing and stabilisation using structural and vegetative measures

This technology addresses the soil erosion and water runoff problems associated with traditional outward-sloping terraces by reshaping the land into a series of level or gently sloping platforms across the slope. This technology is a variant of sloping land agricultural technology (SALT) or contour hedgerow technology. Nitrogen-fixing hedgerow species and quality fodder grass species, which bind the soil, are cultivated along terrace riser margins to improve terrace stability. This also enhances soil fertility and increases fodder availability. The plants are grown in either single or multiple layers. The practice is applied under rainfed conditions and is culturally acceptable and affordable. After establishment, the technology also addresses the problems of fodder scarcity making it easier and less time consuming for women and girls to gather fodder.
The hedgerow and grass species are established between January and June. Complete establishment of this technology may take one year. The first step in creating the terraces is to build retaining walls using cement bags filled with soil which are then supported with bamboo cuttings along the contour (= future terrace risers). This divides the land into the planned terrace sections. The length and width of the terraces depends on the size and shape of the original field. Secondly, the soil is excavated from the upper part of the terraces and is used to build up the lower part above and behind the terrace riser wall to create a level bed. The fertile top soil must be kept aside and later spread over the newly terraced fields. The final step is to plant grass and hedgerow species on the outermost margins of the terrace above the risers.
Maintenance involves slicing the terrace risers once or twice a year with a spade, and smoothing off rills that appear on the surface of terraces after the premonsoon and monsoon periods. Hedgerows should be cut regularly but not more than twice a year, normally to a height of about 50 cm. Grasses should be cut about once to twice a month depending on their rate of growth.
The technology is applied under humid subtropical climate conditions (1300 mm annual rainfall with about 80% of it falling in the monsoon months of June - September). The case study area has hill slopes of 16-30% that are mostly highly erodible red soils (FAO classification: luvisols).

地点

地点: Hokse VDC ward no2, 尼泊尔

分析的技术场所数量:

选定地点的地理参考
  • 85.52133, 27.75651

技术传播: 均匀地分布在一个区域 (0.0126 km²)

在永久保护区?:

实施日期: 50多年前(传统)

介绍类型

技术分类

主要目的
  • 改良生产
  • 减少、预防、恢复土地退化
  • 保护生态系统
  • 结合其他技术保护流域/下游区域
  • 保持/提高生物多样性
  • 降低灾害风险
  • 适应气候变化/极端天气及其影响
  • 减缓气候变化及其影响
  • 创造有益的经济影响
  • 创造有益的社会影响
土地利用

  • 农田
    • 一年一作: 谷物类 - 玉米, 豆科牧草和豆类 - 豆子, 根/块茎作物 - 土豆, wheat, chili, tomatoes
    每年的生长季节数: 3

供水
  • 雨养
  • 混合雨水灌溉
  • 充分灌溉

土地退化相关的目的
  • 防止土地退化
  • 减少土地退化
  • 修复/恢复严重退化的土地
  • 适应土地退化
  • 不适用
解决的退化问题
  • 土壤水蚀 - Wt:表土流失/地表侵蚀 , Wg:冲沟侵蚀/沟蚀
  • 水质恶化 - Ha:干旱化
SLM组
  • 横坡措施
  • 引水和排水
SLM措施
  • 植物措施 - V1:乔木和灌木覆盖层
  • 结构措施 - S1:阶地

技术图纸

技术规范
Schematric view after intervention [terracing and vegetative measures]
Riser slope: 75 degree
Terrace slope: ~ 2 degree

Location: Kubinde

Technical knowledge required for field staff / advisors: high

Technical knowledge required for land users: moderate

Main technical functions: control of concentrated runoff: impede / retard, reduction of slope angle, reduction of slope length

Secondary technical functions: increase of infiltration, increase / maintain water stored in soil, increase in soil fertility

Vegetative measure: on risers
Vegetative material: T : trees / shrubs, G : grass
Number of plants per (ha): 2500
Vertical interval between rows / strips / blocks (m): 1.5
Spacing between rows / strips / blocks (m): 3 to 4
Vertical interval within rows / strips / blocks (m): 0.25

Vegetative measure: Vegetative material: T : trees / shrubs, G : grass

Vegetative measure: Vegetative material: T : trees / shrubs, G : grass

Vegetative measure: Vegetative material: T : trees / shrubs, G : grass

Trees/ shrubs species: Sunhemp(Crotalaria juncea),Tephrosia (Tephrosia candida) and Flemingia (Flemingia microphylla)

Grass species: Napier(Pennisetum purpureum),Molasses (Melinis minutiflora) and Stylo(Stylosanthes guianensis)

Slope (which determines the spacing indicated above): 5.00%

If the original slope has changed as a result of the Technology, the slope today is (see figure below): 5.00%

Gradient along the rows / strips: 75.00%

Terrace: bench level
Vertical interval between structures (m): 1.5
Width of ditches/pits/dams (m): 3-4
Length of ditches/pits/dams (m): 10-15

Construction material (earth): Cement bag filled with soil, Bamboo nets were used to make risers.

Slope (which determines the spacing indicated above): 30%

If the original slope has changed as a result of the Technology, the slope today is: 5%

Vegetation is used for stabilisation of structures.
Author: Madhav Dhakal, A. K. Thaku

技术建立与维护:活动、投入和费用

投入和成本的计算
  • 计算的成本为:
  • 成本计算使用的货币:美元
  • 汇率(换算为美元):1 美元 = -1.0
  • 雇用劳工的每日平均工资成本:1.40
影响成本的最重要因素
In case of projects interested in promoting this technology in the region, the labour cost is the major expenditure in the initial stage.The labour charges are decided by the district soil conservation office.
技术建立活动
  1. Area estimation ( for vegetative measures) (时间/频率: before rainy seasonn/lean period (February))
  2. Selection of fodder grass species (时间/频率: Before rainy season (Feb))
  3. Planting of grasses and hedgerow species on the outward margins (时间/频率: During rainy season.)
  4. Establishment of riser, using cement bags (filled with soil) and bamboo culms for terrace stabilisation (时间/频率: Beginning of rainy season(May))
  5. Terrace leveling:The length and width of the terraces depends on the size and shape of the field. Excavate soil from the upper part of the terrace field and use it to build up the lower part behind the terrace riser wallt creat a level plateform/bed. (时间/频率: Beginning of rainy season(May))
技术建立的投入和成本
对投入进行具体说明 单位 数量 单位成本 (美元) 每项投入的总成本 (美元) 土地使用者承担的成本%
劳动力
Labour ha 1.0 970.0 970.0 50.0
设备
Total costs ha 1.0 92.0 92.0 100.0
植物材料
Seeds ha 1.0 25.0 25.0
Seedlings ha 1.0 30.0 30.0
Bamboo culms 80.0 1.0 80.0 50.0
施工材料
Cement bags ha 1.0 80.0 80.0 50.0
其它
Supervision charge ha 1.0 10.5 10.5
技术建立所需总成本 1'287.5
技术建立总成本,美元 -1'287.5
技术维护活动
  1. Hedgerow/grass maintenance: Hedgerows are cut regularly but not (时间/频率: Grass is cut once or twice a month.)
  2. (Re)plantation of hedge species if necessary (时间/频率: Before monsoon /1*/year)
  3. Surface and riser maintenance: smooth the surface/rills on the (时间/频率: after pre monsoon and after monsoon/2 */ year ,Jun)
技术维护的投入和成本
对投入进行具体说明 单位 数量 单位成本 (美元) 每项投入的总成本 (美元) 土地使用者承担的成本%
劳动力
Labour ha 1.0 310.0 310.0 100.0
设备
Tools total costs ha 1.0 20.0 20.0 100.0
植物材料
Seeds ha 1.0 6.0 6.0 100.0
Seedlings ha 1.0 6.0 6.0 100.0
技术维护所需总成本 342.0
技术维护总成本,美元 -342.0

自然环境

年平均降雨量
  • < 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
  • 潮湿的
  • 半湿润
  • 半干旱
  • 干旱
关于气候的规范
以毫米为单位计算的年平均降雨量:1304.0
Thermal climate class: subtropics
斜坡
  • 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
海拔
  • 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.
......应用的技术
  • 凸形情况
  • 凹陷情况
  • 不相关
土壤深度
  • 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)
  • 粗粒/轻(砂质)
  • 中粒(壤土、粉土)
  • 细粒/重质(粘土)
土壤质地(地表以下>20厘米)
  • 粗粒/轻(砂质)
  • 中粒(壤土、粉土)
  • 细粒/重质(粘土)
表土有机质含量
  • 高(>3%)
  • 中(1-3%)
  • 低(<1%)
地下水位
  • 表面上
  • < 5米
  • 5-50米
  • > 50米
地表水的可用性
  • 过量
  • 中等
  • 匮乏/没有
水质(未处理)
  • 良好饮用水
  • 不良饮用水(需要处理)
  • 仅供农业使用(灌溉)
  • 不可用
水质请参考:
盐度是个问题吗?

洪水发生
物种多样性
  • 中等
栖息地多样性
  • 中等

应用该技术的土地使用者的特征

市场定位
  • 生计(自给)
  • 混合(生计/商业)
  • 商业/市场
非农收入
  • 低于全部收入的10%
  • 收入的10-50%
  • > 收入的50%
相对财富水平
  • 非常贫瘠
  • 贫瘠
  • 平均水平
  • 丰富
  • 非常丰富
机械化水平
  • 手工作业
  • 畜力牵引
  • 机械化/电动
定栖或游牧
  • 定栖的
  • 半游牧的
  • 游牧的
个人或集体
  • 个人/家庭
  • 团体/社区
  • 合作社
  • 员工(公司、政府)
性别
  • 女人
  • 男人
年龄
  • 儿童
  • 青年人
  • 中年人
  • 老年人
每户使用面积
  • < 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
规模
  • 小规模的
  • 中等规模的
  • 大规模的
土地所有权
  • 公司
  • 社区/村庄
  • 团体
  • 个人,未命名
  • 个人,有命名
土地使用权
  • 自由进入(无组织)
  • 社区(有组织)
  • 租赁
  • 个人
用水权
  • 自由进入(无组织)
  • 社区(有组织)
  • 租赁
  • 个人
进入服务和基础设施的通道

影响

社会经济影响
作物生产
降低
增加


maize crop by 100%

饲料生产
降低
增加


households of neighbouring village benefitted.

饲料质量
降低
增加

生产区域(耕种/使用中的新土地)
降低
增加

农业收入
降低
增加


by >100% due to higher

社会文化影响
社区机构
削弱
加强


terrace improvement group was formed

Livelihood and human well-being
reduced
improved


Cropping pattern changed due to which, land users were able to produce more. Farm income and price of land increased.

生态影响
土壤水分
降低
增加


nearby hedgerows

土壤覆盖层
减少
改良


along risers

土壤流失
增加
降低


due to levelled surface and hedgerow barrier

Appearance of pests like rats due to introduction of planted
decreased
increased

场外影响
下游洪水(不希望)
增加
减少


Bigger area needs swc measures

下游淤积
增加
降低

Fodder grass seed distribution
decreased
increased


through farmer to farmer dissemination

Nutrients downstream
decreased
increased


due to reduced nutrients leaching on-site

成本效益分析

与技术建立成本相比的效益
短期回报
非常消极
非常积极

长期回报
非常消极
非常积极

与技术维护成本相比的效益
短期回报
非常消极
非常积极

长期回报
非常消极
非常积极

The initial investment is high, but can be recovered within a short period due to yield increment and cash crop production.

气候变化

渐变气候
年温度 增加

非常不好
非常好
气候有关的极端情况(灾害)
局地暴雨

非常不好
非常好
局地风暴

非常不好
非常好
干旱

非常不好
非常好
比较和缓的(河道)洪水

非常不好
非常好
其他气候相关的后果
缩短生长期

非常不好
非常好

采用和适应

采用该技术的地区内土地使用者的百分比
  • 单例/实验
  • 1-10%
  • 11-50%
  • > 50%
在所有采用这种技术的人当中,有多少人在没有获得物质奖励的情况下采用了这种技术?
  • 0-10%
  • 11-50%
  • 51-90%
  • 91-100%
户数和/或覆盖面积
16 households in an area of 0.0126 sq km
最近是否对该技术进行了修改以适应不断变化的条件?
什么样的变化条件?
  • 气候变化/极端气候
  • 不断变化的市场
  • 劳动力可用性(例如,由于迁移)

结论和吸取的教训

长处: 土地使用者的观点
  • The price of land increased considerably from NRs 30,000 in 2001 (for 1 ropani – 508.5 sq. m) to between NRs 100, 000 and NRs 150,000 per ropani after the technology was established

    How can they be sustained / enhanced? The price would increase further if irrigation facilities were installed
  • Pedicels of Tephosia and Sunhemp can be used for firewood.
  • Instead of planting only maize a farmer started planting rice (primary crop) and cash crops like potato / tomato (secondary crops).
长处: 编制者或其他关键资源人员的观点
  • The area of levelled terraces nearly doubled in Kubinde village from 2001 to 2003, which is an indicator of increased awareness of the benefi ts of soil and water conservation.

    How can they be sustained / enhanced? Experience sharing would help expand the area
    under improved terraces.
  • Land productivity increased, maize, potato and bean production increased, vegetables and rice production started.

    How can they be sustained / enhanced? Irrigation facility could increase the production capacity of the terraces.
  • Availability of grass/fodder (nitrogen fixing) increased.

    How can they be sustained / enhanced? Planting horticultural
    fruits could increase farm incomes and so it should be promoted and more nitrogen fi xing species (preferably local) should be tried out
弱点/缺点/风险: 土地使用者的观点如何克服
  • In the fi rst year of implementation, maize production was reduced due to soil amendment a phenomenon which is likely to occur with new
    terrace formation
弱点/缺点/风险: 编制者或其他关键资源人员的观点如何克服
  • Presently the vegetative technology is confined to terrace margins it should be extended to the risers also.

参考文献

编制者
  • Madhav Dhakal
Editors
审查者
  • David Streiff
  • Alexandra Gavilano
实施日期: June 7, 2011
上次更新: Sept. 5, 2019
资源人
WOCAT数据库中的完整描述
链接的SLM数据
文件编制者
机构 项目
主要参考文献
  • ICIMOD (2002) Hydro-meteorological Year Book of Jhikhu Khola Watershed. Kathmandu: ICIMOD: ICIMOD
  • Mathema, P.; Singh, B.K. (2003) Soil ErosionStudies in Nepal: Results and Implications. Kathmandu: Government of Nepal, Department of Soil Conservation and Watershed Management:
  • Mathema, P. (2003) Watershed Managementin South Asia. Kathmandu: Government of Nepal, Department of Soil Conservation and Watershed Management:
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