3D Agro-ecological Land Use Planning Using Surfer Tool for Sustainable Land Management in Sumani Watershed, West SumatraIndonesia.

Estimation of soil erosion 3D (E3D) provides basic information that can help manage agricultural areas sustainably, which has not been sufficiently conducted in Indonesia. Sumani watershed is main rice production area in West Sumatra which has experienced environmental problem such as soil erosion and production problem in recent years. 3D Agro-ecological land use planning based on soil erosion 3D hazard and economic feasibility analyses consist of production cost and prize data for each crop. Using a kriging method in Surfer tool program, have been developed data base from topographic map, Landsat TM image, climatic data and soil psychochemical properties. Using these data, the Universal Soil Loss Equation was used for spatial map of soil erosion 3D and proposed a 3D agro- ecological land use planning for sustainable land management in Sumani watershed. A 3D Agro-ecological land use planning was planned under which the land use type would not cause more than tolerable soil erosion (TER) and would be economically feasible. The study revealed that the annual average soil erosion from Sumani watershed was approximately 76.70 Mg ha^-1 yr^-1 in 2011 where more than 100 Mg ha^-1 yr^-1 was found on the cultivated sloping lands at agricultural field, which constitutes large portion of soil erosion in the watershed. Modification of land use with high CP values to one with lower CP values such as erosion control practices by reforestation, combination of mixed garden+beef+chicken (MBC), terrace (TBC) or contour cropping+beef+chicken (CBC) and sawah+buffalo+chicken (SBC) could reduce soil erosion rate by 83.2%, from 76.70 to 12.9 Mg ha^-1 yr^-1, with an increase in total profit from agricultural production of about 9.2% in whole Sumani watershed. [ABSTRACT FROM AUTHOR]