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close this bookResource Management for Upland Areas in Southeast Asia - An Information Kit (IIRR, 1995, 207 p.)
close this folder3. Soil and water conservation approaches
View the documentIntroduction to soil and water conservation approaches
View the documentBench terraces
View the documentComposting
View the documentContour tillage/planting
View the documentCover crops
View the documentCrop rotation
View the documentDiversion ditches
View the documentDrop structures
View the documentGrass strips
View the documentHedgerows
View the documentMinimum tilIage/zero tillage
View the documentMulching
View the documentRidge terraces
View the documentShifting cultivation
View the documentSoil barriers
View the documentSoil traps
View the documentWater harvesting

Introduction to soil and water conservation approaches

In recent years, a new approach to soil and water conservation has been emerging, based on experience gained through farming systems research. This approach, sometimes called land husbandry, shifts the emphasis from looking only at what is happening to the soil (e.g., symptoms of erosion) to examining why erosion is taking place (e.g., the underlying causes of erosion). Examining the why component involves understanding the biophysical and socioeconomic factors that contribute to land degradation.

The figure below illustrates the balance of interactions between the biophysical environment and the socioeconomic environment in developing sustainable land-use systems. Due to the biophysical characteristics of many upland areas of Southeast Asia, the loss of soil and water resources remains a critical problem.

The following section outlines 16 soil and water conservation and soil fertility management practices that can make up an integrated approach to upland farm management. Some of the practices focus more on agronomic principles, others more on engineering strategies. However, all of the practices attempt to balance the conservation and production objectives of the farm household. There is a tremendous variability within each of the practices presented and very few speciesspecific recommendations are given. Instead, a description and analysis of each of the practices are presented, focusing on the advantages, limitations and the biophysical and socioeconomic factors which might affect adoption or rejection of the practice.


Balancing agriculture and natural resource management systems

Some key principles for soil/water conservation

Loss of soil productivity is much more important than the loss of the soil itself. Therefore, soil conservation must be an integral part of a general agricultural development strategy that focuses on improved production practices. Generally, conservation measures designed to control soil loss precede soil improvement practices. However, the two are interrelated and must be considered in combination, even if one practice would actually follow the other in sequence.

Erosion is a consequence of how the land is used and is not itself the cause of soil degradation. Land degradation should be prevented before it occurs, rather than attempting to develop a cure afterwards.

Land has been studied too much in soil conservation programs, whereas the land user (the farm household) has been studied too little. A conservation program that aims to solve a land degradation problem through treatment of causes requires a bottom-up approach based on a detailed knowledge of the farm and the farm household as a holistic land-use system. Top-down programs, on the other hand, tend to focus primarily on the symptoms of erosion through subsidized terracing, promotion of alley cropping, or other measures which have had mixed success when introduced by outside agencies.

In upland systems, plant yields are reduced more by a shortage or excess of soil moisture than they are by soil loss. Therefore, there should be more emphasis on rain water management, particularly water conservation and less on soil conservation per se. Consequently, agronomic process (tillage, mulching) are potentially more significant than mechanical measures in preventing erosion and runoff.

Soil conservation efforts will be more successful when applied through long-term programs rather than through short, fixedterm approaches.

The farm household and its environment should be the focal point of every soil conservation program.

Farmers need to be convinced of the short-term benefits which will result from change. It is important to address farmers' immediate needs through the development and introduction of production strategies that are both conservation-effective and which will provide production returns to the farmers.