<![CDATA[ABSTRACT Effect of Source Rocks and Soil Chemical Towards Land Fertility Potential in Sula Kepulauan District, North Maluku Province. The study aimed to determine the condition of soil fertility potential. Parameters used as the basis of assessment of potential fertility of the soil were the type of main rock, weathering processes and mineral content of the native rock while chemically research was emphased on organic matter content, soil pH, CEC, base saturity and essential nutrients (N, P, K). General lithology in the study area were grouped into rocks and rock volkan sediman. Aluvio-marine sedimentary rocks and aluvio-collovium were deposition materials from a variety of rocks in the study contained a number of nutrients and organic matter. Meanhile volkan rocks included basalt and andesite-granidiorit neutral to alkaline. Contained elements that produced fertile lands both physically and chemically. Based on the analysis, the average soil was classified as slightly acid (pH 5.6). The lower layers of soil reaction on average relatively was acidic (pH 5.1). Soil organic matter in the form of organic-C showed the top layer of a low average (1.58%), whilst the layer below average was very low (0.83%). CEC soil layers above and below the average were moderate (20.66 me/100 g) and (19.6 me/100 g). Base saturations (KB) to these two layers of soil on top and below the average were classified as moderate (55%) and (51%). Levels of nitrogen (N-total) topsoil with layers below average are low valued (0.18%) and (0.11%). Classified as very low, phosporus level in both layers were above the average which were 5.40 ppm and 3.10 ppm respectively. Potassiums were very low in the second layer of 5.13 mg/100 g and 3.81 mg/100 g. The parameters used to assess soil fertility status were CEC, KB, P2O5 which were extracted with HCl 25%, and K2O was extracted with HCl 25% and C-organic soil. Potential assessment of soil fertility status based on lithology and soil chemistry acquired the status of soil fertility was low.Keywords: potential soil fertility, maint rock, chemical ABSTRAK Kajian ini bertujuan untuk mengetahui kondisi kesuburan tanah potensial. Parameter yang dijadikan dasar penilaian potensi kesuburan tanah adalah jenis, proses pelapukan, dan kandungan mineral batuan induk sedangkan secara kimia penelitian ditekankan pada kandungan bahan organik, pH tanah, KTK, KB, dan unsur hara esensial (N, P, K). Secara umum litologi di wilayah studi dikelompokan ke dalam batuan sediman dan batuan volkan. Batuan sedimen aluvio-marine dan aluvio-koluvium merupakan bahan-bahan endapan dari berbagai batuan di wilayah studi yang banyak mengandung unsur hara dan bahan organik. Batuan volkan meliputi andesit-basal dan granidiorit bersifat netral sampai basa, mengandung unsur-unsur yang menghasilkan tanah-tanah subur baik secara fisik maupun kimia. Berdasarkan hasil analisis tanah pH rata-rata tergolong agak masam (pH 5,6). Lapisan bawah reaksi tanah rata-rata tergolong masam (pH 5,1). Bahan organik tanah dalam bentuk C-organik menunjukkan pada lapisan atas rata-rata rendah (1,58%), sementara lapisan bawah rata-rata sangat rendah (0,83%). KTK tanah lapisan atas maupun bawah rata-rata tergolong sedang (20,7 me/100 gram) dan (19,6 me/100 gram). Kejenuhan basa (KB) tanah pada keduan lapisan atas dan bawah rata-rata tergolong sedang yaitu (55%) dan (51%). Kadar nitrogen (N-total) tanah lapisan atas sama dengan lapisan bawah rata-rata tergolong rendah (0,18%) dan (0,11%). Kadar fosor (P2O5) tergolong sangat rendah, di kedua lapisan atas rata-rata sebesar 5,40 dan 3,10 me/100g. Unsur hara kalium (K2O) sangat rendah pada kedua lapisan 5,13 mg/100 gram dan 3,81 mg/100 gram. Parameter yang digunakan untuk menilai status kesuburan tanah yaitu KTK, KB, P2O5 yang diesktrak dengan HCl 25%, sedangkan K2O diekstrak dengan HCl 25% dan C-organik tanah. Penilaian potensi status kesuburan tanah berdasarkan litologi dan kimia tanah diperoleh status kesuburan tanah tergolong rendah.Kata kunci: kesuburan tanah potensial, batuan induk, kimia]]>
