Forward sloping terrace stabilised with aligned poplar trees and adjacent grass strips (Erik Bühlmann (Berne, Switzerland))
On steep and severely eroded cropland a forward sloping terrace (15% gradient) was established by moving available earth with a bulldozer. Below the terraced field, a cut-off drain diverts excessive rain and irrigation water to an existing gully. The terrace and the cut off drain are stabilised by an aligned tree barrier (poplar trees planted in 0.5 metre intervals), and by two parallel grass strips of 1-2 metres in width.
The terrace was built using a bulldozer. Digging the cut-off drain and planting the poplar cuttings was done by hand. For the initial establishment of the grass strip clods were transferred from a neighbouring pasture. The poplar trees are pruned in early spring; the cut off-drain needs to be cleared of washed in soil after heavy storm events. The described terrace is established on steep cropland prone to soil erosion. The technology is relatively simple to implement.
Purpose of the Technology: The terrace was established to reduce soil erosion and subsequent fertility decline through the reduction of the slope angle. The tree barrier is planted because of the usefulness of poplar trees for construction purposes and to mark field boundaries; its capability of acting as a stabilising terrace is a very useful extra side effect.
Establishment / maintenance activities and inputs: Establishment costs and the rather low maintenance costs are offset by the benefits of the harvested wood produced. Poplar trees can be gradually felled and used for construction purposes 15 years after they are initially planted. Through reduction of the slope angle, the risk of soil erosion is lowered significantly. However, poplar trees can only be planted on land where sufficient water for irrigation is available, since they need to be watered on a weekly basis during the summer. Furthermore, the technology covers land which then cannot be used for cultivation of food crops.
Location: Faizabad Rayon, RRS, Tajikistan
No. of Technology sites analysed:
Spread of the Technology: evenly spread over an area (approx. 0.1-1 km2)
In a permanently protected area?:
Date of implementation:
Type of introduction
| Specify input | Unit | Quantity | Costs per Unit (n.a.) | Total costs per input (n.a.) | % of costs borne by land users |
| Labour | |||||
| Building terrace | ha | 1.0 | 80.0 | 80.0 | 100.0 |
| Planting trees | ha | 1.0 | 75.0 | 75.0 | 100.0 |
| Equipment | |||||
| tools | ha | 1.0 | 10.0 | 10.0 | 100.0 |
| Total costs for establishment of the Technology | 165.0 | ||||
| Total costs for establishment of the Technology in USD | 165.0 | ||||
| Specify input | Unit | Quantity | Costs per Unit (n.a.) | Total costs per input (n.a.) | % of costs borne by land users |
| Labour | |||||
| Prunning | ha | 1.0 | 12.0 | 12.0 | 100.0 |
| Cutting | ha | 1.0 | 3.0 | 3.0 | 100.0 |
| Total costs for maintenance of the Technology | 15.0 | ||||
| Total costs for maintenance of the Technology in USD | 15.0 | ||||
due to increase in soil fertility
poplar trees gradually harvested for construction purposes
area occupied by grass strips, barriers and ditches
tree barriers impede accessibility with machines
