|Resource Management for Upland Areas in Southeast Asia - An Information Kit (IIRR, 1995, 207 p.)|
|3. Soil and water conservation approaches|
Hedgerows are one of the simplest erosion control practices on sloping land (see Ridge terraces and Contour tillage). Nitrogen-fixing trees/shrubs, grasses, fruit trees or other crops, such as pineapples or banana, are planted in rows along the contour. Various tree and crop species are established in the hedgerow to enhance farm income and diversity. Hedgerows help slow down the passage of rainwater and trap soil to gradually form natural terraces. They also improve soil fertility and crop production. Contour hedgerow cultivation is an indigenous practice in Vietnam, Indonesia, the Philippines and Thailand and is now adopted in many other countries.
· Reduces soil erosion.
· Improves soil fertility and soil moisture.
· Provides biomass for green leaf manure.
· Provides shading for young plants.
· Serves as a source of fodder, fuelwood and light construction materials.
· Improves soil structure and water infiltration.
· Provides a source of mulch.
· Loss of land for cultivation due to establishment of contour hedgerow (at least 10% of cultivated land is used).
· Hedgerows compete with food crops planted between the rows for light, soil nutrients and moisture (in dry season). Root pruning and trimming can limit this competition.
· Hedgerow plants may be hosts to pests.
· Effective retention of excess water may result in soil slippage on steep slopes.
Factors affecting adoption
· Low or high temperatures may cause sterility of some hedgerow species.
· It is difficult to establish contour hedgerows on very steep lands (>50 degrees).
· Most nitrogen-fixing species are not adapted to acid soils.
Lack of selected seeds/tree stock.
Lack of money to purchase seeds/tree stock.
Lack of time/labor to establish contour hedgerows.
Lack of land ownership/tenure.
Farmers fear that hedgerows produce no food or income.
Farmers feel that the hedgerow competes with their food crops and harbors pests (Central Java).
Farmers who use traditional cultivation tools and methods (e.g., hoes, or planting down the slope) do not like hedgerows because they are inconvenient.