Judul: Soil Hydraulic Properties of Forest, Agroforestry and Cassava field in Gunung Walat Education Forest (GWEF).
Abstrak: Soil hydraulic properties expressed by water retention function and hydraulic conductivity. Water retention function is an expression of ability to store water and hydraulic conductivity is an expression of ability to transmit water. Hydraulic properties are fundamental in order to study water balances, irrigation, pollutant movement and transport processes occurred in soil. Gunung Walat Education Forest (GWEF) is one of the forest area that covered by good forest and giving benefits to surrounding area, such as providing water supply. There are agroforestry areas in GWEF and cassava field close to GWEF. Difference of land use may affect the hydraulic properties therefore hydraulic properties of soil of three land uses is important to be studied to recommend better land use management in HPGW. The objective of research to compare soil hydraulic properties of forest, agroforestry and cassava field in GWEF and the effect to water storage and vertical flow in soil. Lognormal model (LN) Kosugi (1996) is used for analysis hydraulic properties while one dimensional vertical flow simulation was done by Model of Richard’s equation (1931) and calculation of model wa done by using software HYDRUS 1D 4.14. Data collection and analysis conducted in July 2008 while data processing was done in November to December 2010. Result shows, forest has highest water retention, whereas agroforestry has highest ability to transmit water, this parameter is indicated by highest LN parameter: s-r, m and . Result of one dimensional vertical flow simulation at drying process showed that generally, flux on bottom layer more high than upper layer and agroforestry has highest total flux than forest and cassava field. While simulation at wetting process, soil at upper layer is responded to the water from rain with high flux rather than the soil at the bottom layer and then also decreased first when rain stop with small flux. Forest soil most responsive in flux change and has highest total flux., Sifat hidrolika tanah digambarkan oleh retensi air tanah dan konduktivitas hidrolika yang menunjukan kemampuan menyimpan dan mengalirkan air. Sifat hidrolika tanah penting untuk diketahui karena merupakan pengetahuan dasar untuk mempelajari neraca air, irigasi, gerakan polutan dan proses perpindahan yang terjadi di dalam tanah. Hutan Pendidikan Gunung Walat (HPGW) merupakan salah satu kawasan hutan yang terjaga keberadaan tegakan hutannya yang memberikan manfaat bagi wilayah sekitar, salah satunya sebagai pemasok air. Di area HPGW terdapat juga agroforestri dan disekitar HPGW terdapat kebun singkong. Penggunaan lahan yang berbeda kemungkinan akan berdampak terhadap sifat hidrolika tanahnya, sehingga sifat hidrolika tanah dari ketiga bentuk penggunaan lahan tersebut perlu diketahui sebagai masukan bagi pengelolaan lahan di HPGW. Tujuan penelitian ini untuk mengetahui perbedaan sifat hidrolika tanah di lahan berhutan, agroforestri dan kebun singkong di HPGW dan dampaknya terhadap penyimpanan dan pengaliran air dalam tanah secara vertikal. Model lognormal (LN) Kosugi (1996) digunakan untuk analisis sifat hidrolika tanah sedangkan simulasi aliran dalam tanah satu dimensi menggunakan model persamaan Richard (1931), perhitungan model tersebut dilakukan dengan menggunakan bantuan perangkat lunak HYDRUS 1D 4.14. Pengambilan dan analisis data dilaksanakan pada Juli 2008 sedangkan pengolahan data dilakukan pada November sampai Desember 2010. Hasil menunjukan bahwa tanah hutan
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