|Resource Management for Upland Areas in Southeast Asia - An Information Kit (IIRR, 1995, 207 p.)|
|3. Soil and water conservation approaches|
In this system, simple farm implements such as hoes and digging sticks are used to prepare land and plant food crops. Minimum tillage is common and effective in controlling soil erosion, particularly on highly erodible and sandy soils. Examples of minimum tillage operation are rice-cropping systems in Vietnam and Thailand and taro cultivation in the Papua New Guinea lowlands.
Lessens the direct impact of raindrops on bare soil, thus minimizing soil erosion.
Minimizes degradation of soil structure.
Slows down the rate of mineralization, leading to more sustained use of nutrients in the organic matter.
Requires less labor than full tillage.
Can be practiced on marginal soils that might not otherwise be feasible to cultivate.
Inadequate seedbed preparation may lead to poor establishment and low yield of crops such as maize and sweet potato.
Rooting volume may be restricted in soils with massive structures.
Factors affecting adoption
Under no-burn swidden conditions, the soil is covered with tree litter and brush, making it difficult to plow.
Provides an alternative to cultivation using draft animal
Farmers in swidden systems traditionally use and are familiar with minimum tillage practices.