I Putu Santikayasa 2) Water Engineering and Management Asian Institute of Technology Thailand

Transcription

1 I Putu Santikayasa 2) 2) Water Engineering and Management Asian Institute of Technology Thailand 1) Presented as an assignment on Land and Water Conservation and Management Courses (CE74.53) in AIT, Thailand April,

2 Content 1. Background 2. Study Area Description 3. Land Degradation Problem in Java-Indonesia 4. Economic and Agriculture Impact of Land Degradation 5. DPSIR Framework on Land Degradation/Soil Management 6. Conclusion and Recomendation

3 Background What is Land Degradation?

4 Background Why is it important in Indonesia? Indonesia has high population with intensive agriculture system Land degradation is one of the major problem based on past research (1860 s) one-third of the cultivated mountain area of Java was eroding (WRI, 1989) 8% of all agricultural farmland (757,000 ha) being degraded in Java in 1987 (Lindert, 2000) economic effects of degradation on agricultural yields in Java vary from, for example, 4% of dryland crop value (Repetto, 1989)

5 Study Area Description

6 Study Area Description West Java: 560 to 740 m a.s.l. 7E03 S, 108E04 W

7 Study Area Description Soil 70% clay, 30% silt Thickness cm (terrace beds) and 0-70 cm (terrace risers)

8 Study Area Description Climate Warm and humid Drier south-east monsoon Average annual rainfall (data from ) is 2650 mm falling on 176 days

9 Study Area Description Land Use

10 Land Degradation Problem in Java- Indonesia 1619 first Dutch colonists established a settlement (Jakarta) practising irrigated rice cultivation 1700s VOC introduce coffee cultivation introduce the so-called Priangan System, later followed by the Culture System ( ) 1930s 1960s large-scale terracing and land redistribution programs targeting smallholders were launched 1945 : Indonesia Independence Government policy switched from a policy of land redistribution to one encouraging private enterprise and was more tuned to intensification of lowland rice cultivation and industrial development than to the position of smallholder and landless upland farmers

11 Land Degradation Problem in Java- Indonesia 1970s 1980s conservation campaigns and upland development programs initiated farmers were encouraged to terrace their land, plant trees, establish home gardens and introduce other ways of soil conservation regreening programs erosion remains a significant problem, 15% of the island s river basins declared to be in a critical state 1990s Indonesia s Center for Soil and Agricultural Research recently completed a large effort to collect and harmonize historical measurements of soil nutrients, organic matter and other soil characteristics

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15 Land Degradation Problem in Java- Indonesia The major land degradation in Java (Lindert, 2000): Organic matter of the topsoil dropped from 1940 to 1970, and rose thereafter but has not yet reached the 1940 level. Gain of around 44% in total phosphorus Potassium levels risen, around 28%, It, too, would be due to fertilizer application especially on food crops. The ph levels have fluctuated. Since 1970, the ph has generally risen.

16 What is the Impact of Land Degradation on Economic and Agriculture? Economic Impact The cost of soil erosion to agriculture rainfed of Java ranged from 4.1 percent to 4.7 percent of production, or in economic value terms, around 0.04 percent of the value of annual agricultural output (Repetto, 1989)

17 What is the Impact of Land Degradation on Economic and Agriculture? Agriculture Impact Productivity per unit land was highest where population density is high Water supply and proximity to large non-agricultural populations have important positive effects on productivity. Soil organic matter content and nitrogen appear to play a positive if weak role in effecting productivity in Java, but the other nutrients did not show up clearly. Other inputs (work animals, machinery and fertilizer) show positive productivity effects in the islands Topsoil chemical quality either dropped by 3% ( )

18 DPSIR Framework on Land Degradation/Soil Management What is DPSIR? Integrated Environmental Assessment (IEA) 1. Driving forces, human populations and human activities 2. Pressures, emissions of pollutants to air, water and land 3. State, effects of pressure on the physical, chemical and biological quality of soil 4. Impacts, effects of the altered physical, chemical and biological quality of soil on the soilitself 5. Responses, the societal responses to environmental issues

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22 DPSIR analysis on Land Degradation in Indonesia Driving Force Population and economic growth Insecurity in land tenure and the marginal revenue Socio-culture Pressure Urbanization water uses water quality Decline in dry season water yield Removal of forest gradually State Problem of soil erosion and diminished agriculture productivity, flooding and sedimentation in lowlands

23 DPSIR analysis on Land Degradation in Indonesia Impact Soil nutrient loss Soil erosion Flood, landslide Response Improving soil productivity Restoring degraded soil Solving watershed problem Policy and measure

24 Activity and Measure to Reduce Land Degradation This method was invented by Dr. Kamir R. Brata, a researcher of Bogor Agriculture University (IPB) Indonesia (2000)

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30 Conclusion and Recommendation Java has followed the path of land-scarce countries as expected by Hayami and Ruttan (1985) by adopting land-replacing technologies. This has been accompanied by increases in labor productivity, though not at the same rate. Major impacts of land degradation on economic and agriculture DPSIR has applied to assess land degradation in Java Many activity has been done to reduce the impact of degradation More research is needed to determine the potential of alternative form of agriculture with respect to the restoration of soil fertility

31 Thank You Maraming salamat sa inyo ขอบค ณมาก Je vous remercie Bayarlalaa chei-zu tin-bar-te شكرا Terima Kasih

32 I Putu Santikayasa Water Engineering and Management Asian Institute of Technology Thailand