ANALISIS ERODIBILITAS TANAH DI DESA HARGOTIRTO DAN HARGOWILIS, KECAMATAN KOKAP, KABUPATEN KULON PROGO

IGA METTA SEKAWATI, Dr. Ir. Ambar Kusumandari., M.E.S

2017 | Tugas Akhir | D3 PENGELOLAAN HUTAN SV

Desa Hargotirto dan Desa Hargowilis memiliki variasi geomorfologi diantaranya, dapat dilihat melalui relif dan kelerengan. Lahan yang ada di wilayah Sub Das Ngrancah ini merupakan lahan kritis yang memiliki tingkat erosi tinggi. lahan yang di dominasi untuk kegiatan pertanian dan agrowisata ini menimbulkan dampak erosi yang cukup besar. Oleh karena itu perlunya perhitungan erodibilitas tanah untuk mengurangi adanya erosi sehingga data yang dihasilkan mampu dimanfaatkan sebagai salah satu arahan dalam perencanaan pengolahan lahan. Tujuan penelitian untuk (1) Menghitung indeks erodibilitas tanah di lokasi penelitian (2) Menganalisis sebaran erodibilitas tanah di daerah penelitian. Penelitian ini dilakukan di Desa Hargowilis dan Desa Hargotirto Kecamatan Kokap Kabupaten Kulon Progo Yogyakarta. Metode penelitian yang digunakan yaitu metode Stratified Sampling dan penetapan nilai erodibilitas tanah (K) berdasarkan rumus Wischmeier and Smith (1978). Hasil penelitian menunjukkan bahwa, (1) indeks erodibilitas (K) beberapa jenis tanah di Desa Hargotirto dan Hargowilis dengan nilai terendah sebesar 0,24 dan nilai erodibilitas tertinggi sebesar 0,54. (2) Distribusi tingkat erodibilitas tanah tinggi terdapat pada satuan lahan C: Hargowilis Kebun/III/Latosol sebesar 0,52 meliputi luas 371,25 Ha dengan prosentase luas 23,2% dari luas, dan G: Hargotirto Rumput/II/Latosol nilai K sebesar 0,54 meliputi luas 2,05 Ha besar proserntase 0,1 %, Tingkat erodibilitas tanah sedang terdapat disatuan lahan A: Hargotirto pemukiman/III/ Latosol nilai K sebesar 0,32 dan prosentase luas sebesar 12,2% meliputi luas 195,51 Ha dan lokasi lahan B: Hargotirto Kebun/II/Latosol sebesar 0,32 meliputi luas 381,39 Ha dan prosentase luas 23,8%, lahan D: Hargotirto Belukar/III/Latosol nilai K 0,26 dengan luas 72,76 Ha, prosentase luas 4,5% dan lahan E: Hargowilis Pemukiman /II/Latosol sebesar 0,24 meliputi luas 197,93 Ha, Prosentase luas 12,4% terakhir tingkat erodibilitas agak tinggi terdapat pada lahan F: Hargowilis Tegalan/II/Latosol sebesar 0,33 meliputi luas 381,69 Dengan prosentase luas 23,8%.

Hargotirto and Hargowilis village have various geomorphology, those are can be seen through the relief and the slope. The land which is located in Sub Das Ngrancah is a critical land which has high level of erosion. This land is dominated for the use of agriculture and agro-tourism which causes quite huge erosion effects. Therefore, it is needed to calculate the soil erodibility to decrease the erosion so that the generated could be used as one of guidance for land management planning. The purpose of this research is (1) To calculate the index of soil erodibility in the research location (2) To analyze the soil erodibility distribution in the research location. The research was conducted in Hargowilis and Hargotirto village Kokap Subdistrict Kulon Progo Regency Yogyakarta. The research method to be used is Stratified Sampling Methode and determination of soil erodibility value (K) based on Wischmeier and Smith (1978) formula. The result of the research indicated that, (1) erodibility index (K) from several kinds of soils in Hargotirto and Hargowilis village had the lowest value about 0, 24 and the highest erodibility value was about 0,54. (2) The distribution of high level soil erodibility was found at C: Hargowilis Garden/III/Latosol was 0,52 including 371,25 Ha of large with 23,2% large percentage of surface area and G: Hargotirto grass/II/Latosol K value was 0, 54 including 2,05 Ha of large and 0,1% of percentage. The middle level of soil erodibility was found at A: Hargotirto Settle/III/Latosol the K value was 0, 32 and large percentage was 12,2% including the surface area of 195,51 Ha and the location of land B: Hargotirto garden/II/Latosol was 0, 32 including 381, 39 Ha of surface area and 23, 8% of large percentage, land D: Hargotirto Shrubs/III/Latosol the K value was 0,26 with 72,76 Ha of surface area, large percentage was 4,5% and land E: Hargowilis housing/II/Latosol was 0, 24 including 197, 93 Ha of surface area, large percentage was 12,4%. The last was the high level of soil erodibility was found at land F: Hargowilis Field/II/Latosol was 0, 33 including 381, 69 of surface area with large percentage of 23, 8%.

Kata Kunci : erodibility Value, erosion, soil