A fully developed check dam: The stem cuttings - in this case associated with Bromelia pinguin - have grown to form a dense living barrier, and the area behind the dam has become level. (Mats Gurtner)
Stem cuttings from specific tree species have the ability to strike roots and continue growing after being planted into the earth. In this case study local species have been used to create check dams in gullies: these include jinocuebo (Simaroubaceaes bombacaceaes, and also jobo, tiguilote, pochote from the same family). Other suitable species are jocote (Spondias purpurea) and madero negro (Gliricidia sepium). As an option the pinapple-like piñuela (Bromelia pinguin) can be planted in association with the stem cuttings to further reinforce the system. Tree stems are cut into pieces 5-15 cm thick and 1.5-2.5 m long, depending on the depth of the gully. The cuttings are planted to half of their length, and formed into semi-circular barriers (see diagram). The dams retard runoff and thus retain eroded sediment. Spacing between dams depends on the gradient of the gully bed. For example on a 15% slope it is recommended to build a dam every 4 meters (see spacing under establishment activities). Between dams, the gully gradually fills up with eroded soil, the speed of the runoff is further reduced and agricultural land that has been divided by the gully is reconnected. Large and deep gullies may change over time into a sequence of narrow fertile terraces where crops can be grown.
However, the check dams should be seen as part of an integrated catchment management and protection plan, and thus be supported by other SWC measures on the lateral slopes, such as retention ditches and/or live barriers laid out along the contour. Erosion and runoff control on the sides of each gully is an essential part of the rehabilitation process. These check dams of rooted poles are more robust and durable than stone dams in soils of sandy/ loamy texture. On moderate and steep slopes a combination of stem cutting and stone dams is recommended.
After two to three years the barriers should be pruned - yielding wood and fodder. Dead poles should be replaced and the dam widened if necessary.
In this case study the dams are constructed in a semi-arid region with erratic rainfall where gullies are common on agricultural land, be it cropland or grazing land. The land users are mainly peasant farmers, growing crops for subsistence on smallholdings, and living in very poor conditions. This system of gully rehabilitation is promoted by an NGO entitled ‘Asociación Tierra y Vida’ through farmerto-farmer (campesino a campesino) extension.
ទីតាំង: Carazo, Nicaragua, Santa Teresa, Paso de la Solera, ប្រទេសនីការ៉ាហ្គា
ចំនួនទីកន្លែងបច្ចេកទេស ដែលវិភាគ:
ការសាយភាយនៃបច្ចេកទេស:
តើស្ថិតក្នុងតំបន់ការពារអចិន្ត្រៃយ៍?:
កាលបរិច្ឆេទនៃការអនុវត្ត: តិចជាង 10ឆ្នាំមុន (ថ្មី)
ប្រភេទនៃការណែនាំឱ្យអនុវត្តន៍៖
| បញ្ជាក់ពីធាតុចូល | ឯកតា | បរិមាណ | ថ្លៃដើមក្នុងមួយឯកតា (មិនមាន) | ថ្លៃធាតុចូលសរុប (មិនមាន) | % នៃថ្លៃដើមដែលចំណាយដោយអ្នកប្រើប្រាស់ដី |
| កម្លាំងពលកម្ម | |||||
| labour | ha | 1,0 | 100,0 | 100,0 | 100,0 |
| សម្ភារៈ | |||||
| tools | ha | 1,0 | 20,0 | 20,0 | |
| wheelbarrow | ha | 1,0 | 10,0 | 10,0 | 100,0 |
| សម្ភារៈសាងសង់ | |||||
| wood | ha | 1,0 | 60,0 | 60,0 | 100,0 |
| ថ្លៃដើមសរុបក្នុងការបង្កើតបច្ចេកទេស | 190.0 | ||||
| ថ្លៃដើមសរុបក្នុងការបង្កើតបច្ចេកទេសគិតជាដុល្លារ | 190.0 | ||||
| បញ្ជាក់ពីធាតុចូល | ឯកតា | បរិមាណ | ថ្លៃដើមក្នុងមួយឯកតា (មិនមាន) | ថ្លៃធាតុចូលសរុប (មិនមាន) | % នៃថ្លៃដើមដែលចំណាយដោយអ្នកប្រើប្រាស់ដី |
| កម្លាំងពលកម្ម | |||||
| labour | ha | 1,0 | 30,0 | 30,0 | 100,0 |
| សម្ភារៈសាងសង់ | |||||
| wood | ha | 1,0 | 5,0 | 5,0 | 100,0 |
| ថ្លៃដើមសរុបសម្រាប់ការថែទាំដំណាំតាមបច្ចេកទេស | 35.0 | ||||
| ថ្លៃដើមសរុបសម្រាប់ការថែទាំដំណាំតាមបច្ចេកទេសគិតជាដុល្លារ | 35.0 | ||||
where gullies planted
eg madero negro=Gliricidium sepium
medium term
during establishment phase
