Jurnal Tanah dan Iklim最新文献

{"title":"Plot Scale Nitrogen Balance of Newly Developed Lowland Rice at Kleseleon Village Malaka District, Nusa Tenggara Timur","authors":"nFN Sukristiyonubowo, S. Widodo, K. Nugroho","doi":"10.2017/JTI.V41I2.5982","DOIUrl":"https://doi.org/10.2017/JTI.V41I2.5982","url":null,"abstract":" Abstract. Study on plot scale nitrogen balance of newly developed lowland rice was conducted in Kleseleon village, Malaka District, Nusa Tenggara Timur in 2014. The soil was classified as ustifluvent with ustic moisture regime. Five treatments were tested including T0: farmers practices, T1: NPKat recommendation rate + Rice straw compost, T2: NPKat recommendation rate + Smart + Rice straw compost, T3: ¾ NPKat recommendation rate + Smart + Rice straw compost and T4: NPKat recommendation rate + Smart + Rice straw compost, in which N, P  and K were split two times. Nitrogen balance was computed according to the differences between nitrogen gains and losses. To quantify total nitrogen input, nitrogen content in urea, dosage of urea, rate of compost, nitrogen concentration in compost, irrigation water supply, and nitrogen concentrations in rain water were collected. Output parameters included rice grains yield, rice straw production, nitrogen concentrations in rice grains and rice straw. The results indicated that surplus nitrogen balances were taken place in all treatments including the farmer practices. Concerning the environmental, agronomical and economic point of views, the recommendation of urea fertilizer rate at least was about 100 kg ha-1 season-1 like done in the farmer practices plus the compost rate about 3000 kg ha-1 season-1. Urea should be available in the district level every planting season was the urea application rate multiplied by total low land area in Malaka district equal to 1.207 tons district -1 season -1.Abstrak. Percobaan neraca hara nitrogen pada skala petak pada sawah bukaan baru dilaksanakan di Dusun Kleseleon, Kabupaten Malaka, Propinsi Nusa Tenggara Timur pada Tahun Anggaran 2014. Tanah yang digunakan termasuk golongan ustifluvent denga kelembaban tanah ustik. Lima teknologi yang menjanjikan diuji pada percobaan ini meliputi T0: Praktek Petani sebagai kontrol, T1: NPKpada dosis  rekomendasi + Kompos jerami, T2: NPKpada dosis  rekomendasi + Smart + Kompos jerami , T3: ¾ NPKpada dosis  rekomendasi rate + Smart + Kompost jerami dan T4: NPKpada dosis rekomendasi + Smart + Kompos jerami, dimana  N, P  dan K diberikan dua kali. Keseimbangan N dihitung berdasarkan berdasarkan selisih antara nitrogen yang masuk ke lahan sawah dengan nitrogen yang hilangdari lahan sawah . Untuk menghitung nitrogen yang masuk ke lahan sawah diperlukan kandungan N pada urea, dosis pupuk urea, kadar nitrogen dalam kompos,  takaran kompos, air irigasi dan kandungan nitrogen pada air irigasi dan air hujan. Sedangkan nitrogen yang hilang dari lahan sawah meliputi hasil gabah dan produksi jerami serta kadar nitrogen pada gabah dan jerami. Hasil penelitian menjukkan bahwa positif nitrogen balance pada semua perlakuan. Mengingat bahaya pencemaran lingkungan, keuntungan agronomik dan ekonomis yang didapat, pemberian Urea sebaiknya dikurangi dari  250 kg ha-1musim-1 menjadi 100 kg Urea kg ha-1musim-1 seperti pada praktek petani dengan memberi kompos jeram","PeriodicalId":165570,"journal":{"name":"Jurnal Tanah dan Iklim","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129439404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Perbandingan Berbagai Teknik Estimasi Kebutuhan Ruang Terbuka Hijau Di Kota Bandar Lampung","authors":"Rein Susinda Hesty, Andi Gunawan, L. Prasetyo, Aris Munandar","doi":"10.2017/JTI.V43I1.9393","DOIUrl":"https://doi.org/10.2017/JTI.V43I1.9393","url":null,"abstract":"Abstrak . Meningkatkan kualitas ekologis suatu kota dapat dilakukan dengan membentuk ruang terbuka hijau. Perumusan kebijakan ruang terbuka hijau secara berkelanjutan dipengaruhi oleh berbagai kriteria, di mana indikator-indikator dalam kriteria tersebut saling terkait. Penelitian ini bertujuan untuk mengetahui kebutuhan luas ruang terbuka hijau dalam mewujudkan tata kota berkelanjutan di Kota Bandar Lampung. Indikator dalam menentukan kebutuhan ruang terbuka hijau antara lain adalah jumlah populasi, luas lahan, dan emisi CO2. Berdasarkan populasi pada tahun 2017, kebutuhan ruang terbuka hijau sesuai program pemerintah adalah 2.673 ha, sedangkan luas ruang terbuka hijau hanya ada 2.475 ha sehingga ada perbedaan kekurangan ruang terbuka hijau sebesar 197 ha. Lebih jauh, Kota Bandar Lampung berdasarkan luasnya membutuhkan ruang terbuka hijau seluas 5.916 ha. Tingkat emisi CO2 di Kota Bandar Lampung pada tahun 2017 adalah sebesar 9.118 Gg th-1 sedangkan prediksi total emisi CO2 pada tahun 2024 adalah 133.202 Gg CO2-1 th-1. Sehingga luasan yang ruang terbuka hijau yang dibutuhkan adalah sebesar 156 ha. Angka ini akan meningkat sejalan dengan pertumbuhan penduduk. Untuk itu luas ruang terbuka hijau perlu disesuaikan secara berkala untuk penyerapan emisi CO2 dan keserasian kota. Abstract. Improving the ecological quality of a city can be done by creating green open space. The formulation of a green open space policy for harmonious city is influenced by various interrelated factors. This study aimed to estimate the area of green open space in realizing sustainable green open space in Bandar Lampung City. Indicators in determining the needs of green open space were the population, land area, and CO2 emissions. Based on the population in 2017, the green open space requirement as targeted by the local government was 2,673 ha, while the extent of existing green open space was is only 2,475 ha, hence a need for 197 ha more green open space area. Bandar Lampung City based on its area requires a green open space of 5,916 ha. The level of CO2 emissions in Bandar Lampung City in 2017 was 9,118 Gg/year, while the predicted total CO2 emissions in 2024 is 133.202 Gg/CO2/year and hence the city require additional green open space of 156 ha. This number will increase in line with population growth. For this reason, the area of green open space needs to be adjusted regularly for the absorption of CO2 emissions and the harmony of the city.","PeriodicalId":165570,"journal":{"name":"Jurnal Tanah dan Iklim","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128548288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pengaruh Bio-Nano Silika Terhadap Hasil dan Efisiensi Penggunaan Air Kedelai Hitam di Lahan Kering Masam","authors":"L. P. Santi, D. H. Goenadi, Junita Barus, A. Dariah","doi":"10.2017/JTI.V42I1.9156","DOIUrl":"https://doi.org/10.2017/JTI.V42I1.9156","url":null,"abstract":"Abstrak. Kebutuhan kedelai hitam nasional masih tergantung pada pasokan dari luar negeri dan terkendala oleh rendahnya produktivitas. Oleh karena itu, pemanfaatan lahan marginal secara optimal perlu didorong untuk budidaya kedelai hitam. Optimalisasi lahan kering masam dihadapkan pada faktor utama pembatas tanah antara lain kemasaman tanah tinggi, air tersedia terbatas, dan efisiensi penggunaan unsur hara rendah. Silika (Si) dalam bentuk yang siap diserap oleh tanaman (asam silikat) mampu meningkatkan toleransi tanaman terhadap cekaman kekeringan dan meningkatkan efisiensi penggunaan hara. Tujuan penelitian ini untuk mengetahui pengaruh aplikasi bio-nano silika di lahan kering yang bereaksi masam terhadap: (i) hasil kedelai hitam, dan (ii) efisiensi penggunaan air. Kegiatan lapang dilaksanakan di Jatitujuh, Majalengka, Jawa Barat, pada bulan Juli-Oktober 2017 dengan menggunakan rancangan acak kelompok (RAK). Pupuk bio-nano silika diberikan dengan dosis 0, 2, 4, dan 6 L ha-1, sedang pupuk N, P, dan K tunggal diberikan setara dengan 0, 50, 75, dan 100% dosis rekomendasi. Plot kontrol berupa perlakuan standar petani (100% N, P, dan K + 2 ton ha-1 pupuk organik). Plot berukuran 100 m2 dari setiap perlakuan ditanami kedelai hitam varietas Detam-1. Pupuk bio-nano silika diekstraksi dari pasir kuarsa 325 mesh menggunakan larutan asam dan basa. Pupuk bio-nano silika mengandung kadar H4SiO4 > 5% dengan ukuran partikel 18 nm dan dalam aplikasinya diperkaya dengan mikroorganisme pelarut Si, yaitu Aeromonas punctata, Burkholderia cenocepacia, B. vietnamiensis, dan Aspergillus niger. Hasil percobaan menunjukkan bahwa hasil biji kedelai nyata tertinggi diperoleh pada perlakuan 75% NPK + 2 L bio-nano silika ha-1. Aplikasi 4 L ha-1 bio-nano silika dapat menghemat dosis pupuk N, P, dan K sampai dengan 32%. Sementara aplikasi dengan dosis 6 L ha-1 bio-nano silika dapat meningkatkan hasil kedelai hitam var. Detam-1 sampai dengan 36,7% dan menekan kebutuhan air tanaman hingga 65%. Abstract . National black soybean demand is still dependent on import supply and limited by its low productivity. Therefore, the utilization of marginal land needs to be driven for development of black soybean cultivation. The main limiting factors of acid dry land soils are high soil acidity, limited water availability and low nutrients use efficiency. Silica (Si) in plant-available form (silicic acid) is able to improve plant drought tolerance and nutrient use efficiency. The objective of this study was to determine the effect of the application of bio-nano-silica in acid dry land to: (i) black soybean productivity, and (ii) the efficiency of water use. The research was conducted in Jatitujuh area, Majalengka, West Java, in July-October 2017, by using a randomized block design. Bio-nano silica was applied at 0, 2, 4, and 6 L ha-1, whereas single N, P, and K fertilizers were given at 0, 50, 75, and 100% of recommended rate in three replicates and on a 100 m2 plot size each, with control p","PeriodicalId":165570,"journal":{"name":"Jurnal Tanah dan Iklim","volume":"147 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121254417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sifat Tanah pada Tegakan Vegetasi yang Berbeda di Kebun Raya Purwodadi","authors":"Febrina Artauli Siahaan, R. Irawanto, Apriyono Rahadiantoro, Ilham Kurnia Abiwijaya","doi":"10.2017/JTI.V42I2.8837","DOIUrl":"https://doi.org/10.2017/JTI.V42I2.8837","url":null,"abstract":"Abstrak. Lapisan tanah bagian atas merupakan lapisan yang rentan mengalami perubahan. Tingginya keberagaman tumbuhan yang menanungi tanah di Kebun Purwodadi dapat menyebabkan perbedaan sifat fisika dan kimia tanah meski pada luasan dan landuse yang sama. Penelitan yang dilaksanakan pada tahun 2015 ini bertujuan untuk mengetahui pengaruh tegakan vegetasi terhadap sifat tanah lapisan atas Pemahaman tentang perbedaan sifat tanah dapat membantu untuk mengetahui pengelolaan tanah yang tepat. Metode pengambilan sampel tanah yang digunakan adalah purposive random sampling pada 27 plot dengan 3 ulangan. Sampel tanah diambil dari lapisan olah tanah dengan jeluk 0-20 cm. Setiap plot terdiri dari keluarga tumbuhan yang berbeda. Parameter yang diukur adalah Tekstur Tanah, pH Tanah, Kandungan Karbon Organik, Total N, P, K, Ca, Na, Mg, Kapasitas Tukar Kation (KTK) dan Kejenuhan Basa. Hasil penelitian menunjukkan bahwa plot Clusiaceae, Gymnospermae, Arboretum dan Mahoni merupakan tanah yang paling subur dilihat dari kandungan hara tanah. Nilai pH dan kejenuhan basa dipengaruhi oleh ground cover dan C-organik dipengaruhi oleh tutupan kanopi vegetasi atas. Kadar Ca, Na, Mg pada setiap plot bervariasi dari sangat rendah sampai yang sangat tinggi. KTK sebesar 22,38-44,18 me/100g sementara Kalium (K) pada menjadi faktor pembatas pada setiap plot karena kadar yang sangat rendah. Abstract . Topsoil is a susceptible layer that can easily change in its properties. The diversity of plants that shades the Purwodadi Garden’s soil can affect soil physical and chemical properties, even in the same area and landuse. The research carried out in 2015 aims to determine the effect of vegetation stand on the topsoil properties. Understanding the relationship between vegetation stands and soil properties is important in developing the proper soil management system. Soil sampling method used was purposive random sampling on 27 plots with 3 replications. Soil samples were taken from the top 0-20 cm of soils. Parameters measured were Soil Texture, Soil pH, organic carbon content, Total N, P, K, Ca, Na, Mg, Cation Exchange Capacity (CEC) and Base saturation. The results showed that the plots of Clusiaceae, Gymnosperms, Arboretum and Mahogany had the most fertile soils as shown by the nutrient content. Soil pH values and base saturations were affected by the ground cover, meanwhile soil organic C content is affected by the percentage of vegetation canopy. Total nitrogen content was 0.16 to 0.39% and phosphorus content was 2.26 to 13.80%. Ca, Na, Mg contents in each plot varied from very low to very high. The range of CEC values was 22.38-44.18 me/100g while the Potassium (K) was the limiting factor in each plot due to the very low content.","PeriodicalId":165570,"journal":{"name":"Jurnal Tanah dan Iklim","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116194409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kemampuan Konsorsium Bacillus pada Pupuk Hayati dalam Memfiksasi N2, Melarutkan Fosfat dan Mensintesis Fitohormon Indole 3-Acetic-Acid","authors":"Muhimatul Husna, Sugiyanta Sugiyanta, Etty Pratiwi","doi":"10.2017/JTI.V43I2.10371","DOIUrl":"https://doi.org/10.2017/JTI.V43I2.10371","url":null,"abstract":"Abstrak.  Bakteri Bacillus sp. non patogenik memiliki potensi sebagai pupuk hayati. Pupuk hayati di Indonesia sebagian besar terdiri atas konsorsium beberapa macam mikroba. Pupuk hayati yang diuji, “Pupuk X” terdiri atas 10 spesies bakteri Bacillus sp. Penelitian ini bertujuan untuk mengevaluasi efektivitas Pupuk X dalam melarutkan fosfat, memfiksasi N 2 dan mensintesis fitohormon Indole-3-Acetic Acid (IAA), serta mengujinya secara in planta pada bibit padi.  Kemampuan melarutkan fosfat diuji pada media Pikovskaya padat dengan mengamati munculnya zona bening di sekeliling koloni. Kemampuan memfiksasi N 2 secara kualitatif dan kuantitif masing-masing diuji pada media NFB padat dan Acetylene Reduction Assay . Kemampuan sintesis IAA diukur secara kolorimetri pada λ 530 nm, sedangkan pengaruh pupuk hayati cair terhadap bibit tanaman padi diuji secara in planta menggunakan bibit padi varietas IPB3S. Sedikitnya terdapat enam spesies bakteri Bacillus pada pupuk hayati yang digunakan memperlihatkan morfologi koloni berbeda, dengan total populasi mencapai 7,6×10 11 cfu ml -1 dan ukuran sel-sel Bacillus sp. bervariasi antara 2,39-3,01 µm. Pada pupuk hayati ini terdeteksi aktivitas nitrogenase sebesar 0,05685 µm ml -1 jam -1 . Konsorsium Bacillus ini dapat melarutkan fosfat dari sumber Ca 3 (PO 4 ) 2 dengan indeks pelarut fosfat 2,6. Fosfat terlarut tersebut disebabkan karena produksi empat jenis asam organik oleh Bacillus sp., yaitu asam asetat, asam oksalat, asam laktat, dan asam malat dengan konsentrasi sekitar 0,01-1,02 mg l -1 . Konsentrasi IAA pada pupuk hayati cair terdeteksi sebesar 3,0065 µg ml -1 . Inokulasi Pupuk X pada bibit padi dapat meningkatkan jumlah akar lateral 42,8% yang berpotensi meningkatkan serapan hara dalam tanah. Abstract . Non-pathogenic Bacillus sp. has the potential as a biofertilizer. Biofertilizers in Indonesia mostly consist of a consortium of several kinds of microbes. Liquid biofertilizer, “Biofertilizer X” is a compound fertilizer consists of ten species of Bacillus sp. This research was aimed at evaluating the ability of the Bacillus consortium in Biofertilizer X to dissolve phosphate, fix N 2 and synthesize Indole-3-Acetic Acid (IAA) phytohormone, as well as its effect on rice seedling. The ability to dissolve phosphate was tested on solid Pikovskaya media by observing the appearance of a clear zone around the bacterial colony. The ability to fix N 2 qualitatively and quantitatively was tested on solid NFB media and Acetylene Reduction Assay, respectively. The ability of IAA synthesis was measured by colorimetry at λ 530 nm, while the effect of liquid biofertilizers on rice seedlings was tested in planta using IPB3S variety rice seedling. There were at least six species of Bacillus in liquid biofertilizers showing different colony morphologies. The total population reached 7.6 × 10 11 cfu ml -1 and the size of Bacillus sp. varied between 2.39-3.01 µm. Nitrogenase activity of this biofertilizer was detected at 0.05685 µm","PeriodicalId":165570,"journal":{"name":"Jurnal Tanah dan Iklim","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128116615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lahan Bekas Tambang Timah di Pulau Bangka dan Belitung, Indonesia dan Kesesuaiannya untuk Komoditas Pertanian (Ex-mining land in Bangka and Belitung Islands, Indonesia and their suitability for agricultural commodities)","authors":"nFN Sukarman, Rachmat Abdul Gani","doi":"10.2017/JTI.V41I2.7176","DOIUrl":"https://doi.org/10.2017/JTI.V41I2.7176","url":null,"abstract":"Abstrak : Penambangan timah di Indonesia pada umumnya dilakukan dengan sistem terbuka dengan mengeruk dan merusak tanah lapisan atas sehingga mempengaruhi kesesuaian lahan untuk pertanian. Tujuan penelitian ini adalah untuk mempelajari karakteristik tanah dan biofisik lahan di areal bekas tambang timah di Pulau Bangka dan Belitung serta menilai kesesuaiannya untuk tanaman pertanian. Penelitian dilaksanakan pada bulan Maret sampai Mei 2016 dengan metode survei dan pemetaan lahan. Hasil penelitian menunjukkan bahwa lahan bekas tambang di kedua pulau tersebut seluas 125.875 ha. Telah terjadi perubahan bentang lahan, yaitu dengan terbentuknya kolong dan timbunan hasil galian. Timbunan galian dibagi menjadi: (1) Tanah galian bagian atas (tanah pucuk), merupakan campuran antara horison A, B dan horison C tanah asli, (2) Tanah galian bagian bawah berasal dari horison C tanah asli, (3) Tailing berupa pasir kuarsa dan sisa pencucian biji timah, dan (4) Campuran tailing dan galian bagian bawah. T ailing dicirikan oleh tekstur kasar dan kandungan hara yang sangat rendah. Tanah pucuk relatif lebih baik dicirikan oleh tekstur sedang sampai agak kasar, dan kandungan C -organik serta hara paling tinggi dibandingkan bagian lainnya. Logam berat yang ditemukan adalah Cu , Pb , Cd , dan Hg . Tanah galian bagian bawah mengandung logam berat paling tinggi, namun kandungan tersebut tergolong sangat rendah dan dalam batas yang aman. Sebagian besar lahan bekas tambang tergolong kelas N1 (tidak sesuai saat ini) karena lahan sudah mengalami degradasi berat. Masukan yang diberikan harus tinggi, agar tanaman yang dibudidayakan dapat tumbuh secara optimal. Abstract. Tin mining in Indonesia is generally done with an open system by dredging and damaging the topsoil, and hence it changes land suitability. The purpose of this research is to study soil and biophysical characteristics of land in ex-tin mining area in Bangka and Belitung Islands and assess its suitability for agricultural crops. The study was conducted from March to May 2016 with survey and land mapping methods. The results showed that the area of ex-mining land on both islands was 125,875 ha. There has been tremendous changes of the landscape, with the formation of small lakes (voids) and pile of excavation. Heaps of the excavation are: (1) Top soil containing the mixture of horizons A, B and C of the original soil, (2) The bottom part which was derived from C horizon of the original soil, (3) Tailings of quartz sand resulted from washing separating the sand and the ore, and (4) Mixture of tailings and bottom part of soil excavation. Tailing is poorest in fertility and characterized by coarse texture and very low nutrient content. The ‘top soil’ layer is relatively better and characterized by moderate to slightly coarse textures, and the highest in organic and nutrient content than other parts. The heavy metals found were Cu, Pb, Cd, and Hg. The bottom part of excavation contains the highest heavy metals, but the ","PeriodicalId":165570,"journal":{"name":"Jurnal Tanah dan Iklim","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121689366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analisis Karakteristik Kekeringan Lahan Padi Sawah di Wilayah Utara Provinsi Jawa Barat","authors":"Mamenun Mamenun, T. Wati","doi":"10.2017/JTI.V43I1.9402","DOIUrl":"https://doi.org/10.2017/JTI.V43I1.9402","url":null,"abstract":"Abstrak. Kejadian kekeringan di Indonesia disebabkan karena menurunnya curah hujan dalam jangka waktu lama dan sering dipicu oleh kejadian El Nino. Curah hujan pada tahun El Nino dapat menurun 150-200 mm/bulan yang berimplikasi pada penurunan produksi pangan. Kondisi iklim, karakteristik kekeringan, dan korelasi karakteristik kekeringan terhadap luas lahan padi sawah terkena kekeringan dan gagal panen (puso) telah dianalisis di wilayah utara Provinsi Jawa Barat menggunakan indeks presipitasi terstandarisasi (SPI/Standardized Precipitation Index). Data curah hujan bulanan periode 1987 – 2017 dari 30 pos hujan digunakan untuk menghitung SPI3 dan SPI6 serta turunannya. Hasil interpolasi Inverse Distance Weighted (IDW) untuk mengisi data kosong <10% menunjukkan terdapat korelasi 0,6 hingga 0,96 antara hasil interpolasi dengan observasi. Wilayah utara Provinsi Jawa Barat mempunyai pola hujan monsun dengan tipe iklim Oldeman didominasi tipe C3 dan D3. Berdasarkan indeks SPI3 dan SPI6, jumlah kejadian kekeringan tertinggi masing-masing mencapai 18 dan 15 kejadian, durasi kekeringan terpanjang selama 14 bulan dan 22 bulan, tingkat keparahan kekeringan terkuat mencapai 28,9 dan 34,50 dan intensitas tertinggi 2,90 dan 2,53. Karakteristik kekeringan tersebut didominasi pos hujan di Kab. Indramayu dan Majalengka yang terjadi pada periode El-Nino kuat (1997/1998 dan 2015/2016). Korelasi positif antara durasi, tingkat keparahan, intensitas kekeringan terhadap lahan terkena kekeringan dan puso terdapat di sebagian besar pos hujan utara Jawa Barat dengan korelasi bervariasi hingga 0,77 pada SPI3 dan hingga 0,86 pada SPI6. Karakteristik kekeringan untuk lahan padi sawah, diharapkan dapat dimanfaatkan dalam sistem monitoring dan peringatan dini kekeringan serta risiko bencana untuk mencegah gagal panen dan kerugian yang lebih besar. Abstract. Drought occurance in Indonesia is caused by long time decrease of rainfall and triggered by El Nino events. El Nino could reduced rainfall up to 150-200 mm/month and have implications to decreased food production. Climate condition, drought characteristics, and correlation between drought characteristics and the affected paddy field area as well as crop failure (puso) have been analysed for the northern part of West Java province using Standardized Precipitation Index (SPI). Monthly rainfall data in 1987-2017 period from 30 selected rainfall stations were used to calculate SPI3 and SPI6 and its derivatives. The interpolation result of Inverse Distance Weighted (IDW) to fill out <10% empty data showed correlation of 0,6 to 0,96 between observation and interpolated data. The northern part of West Java province has a monsoonal rainfall pattern with Oldeman climate type dominated by C3 and D3. Based on SPI3 and SPI6, the highest drought event reached 18 and 15 events, the longest drought duration were 14 and 22 months, the strongest drought severity reached 28,9 and 34,50, and the highest drought intensity were 2,90 and 2,53. Tho","PeriodicalId":165570,"journal":{"name":"Jurnal Tanah dan Iklim","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134409455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Koreksi Bias Luaran Model Iklim Regional untuk Analisis Kekeringan","authors":"Syamsu Dwi Jadmiko, D. Murdiyarso, Akhmad Faqih","doi":"10.2017/JTI.V41I1.5983","DOIUrl":"https://doi.org/10.2017/JTI.V41I1.5983","url":null,"abstract":"Abstrak : Luaran simulasi model iklim regional perlu dikoreksi karena memiliki bias sistematis secara spasial dan temporal. Kajian ini membahas simulasi koreksi bias menggunakan metode statistik. Data yang dikoreksi adalah data curah hujan luaran simulasi RegCM4. 4 pada periode 1981-2005. Dari simulasi koreksi bias tersebut kami mendapati bahwa koreksi bias menggunakan regeresi linear tidak mampu memperbaiki distribusi spasial maupun pola hujan. Namun, dengan menggunakan regresi polinomial, koreksi bias menunjukkan luaran yang lebih baik terutama dengan regresi polinomial orde 3. Lebih dari itu, regresi polinomial orde 3 yang dikombinasikan dengan intersep yang dikembalikan pada nilai nol memberikan luaran koreksi bias yang terbaik dan dapat digunakan untuk melakukan analisis kekeringan lahan. Kami mendapati bahwa analisis kekeringan dengan metode Standardized Precipitation Index (SPI) yang diuji menggunakan skala waktu 1, 3, 6 dan 12 bulan memberikan hasil terbaik jika menggunakan skala waktu lebih dari 1 bulan. Hal ini dapat dilihat dari hubungannya dengan nilai anomali curah hujan dan jejak kekeringan yang terjadi pada tahun El-Nino seperti tahun 1982/1983, 1986/1987 dan 1997/1998. Abstract. The outputs of regional climate model simulations need to be corrected because of their systematic spatial and temporal biases. This study simulates bias correction using the statistical methods on rainfall data outputs generated by RegCM4.4 during the period of 1981-2005. We found that linier regression did not improve the spatial distribution and pattern of rainfall data. However, by using polynomial regression better results were performed especially third order polynomial. Moreover, when the third order of polynomial regression was combined with the zero intercept, it gave the best bias correction and therefore, can be further used for drought analysis. Standardized Precipitation Index (SPI) method was used to analyze drought index with different time scale of 1, 3, 6 and 12-months. We found that SPI performed well when implemented for time scale more than 1-month. This was demonstrated by the relationship with the rainfall anomaly and drought history during El-Nino years of 1982/1983, 1986/1987 and 1997/1998.","PeriodicalId":165570,"journal":{"name":"Jurnal Tanah dan Iklim","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134503970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tanah-tanah Dari Batuan Ultrabasik di Sulawesi: Kandungan Logam Berat dan Arahan Pengelolaan untuk Pertanian","authors":"Erna Suryani, Sofyan Ritung","doi":"10.2017/JTI.V42I2.9321","DOIUrl":"https://doi.org/10.2017/JTI.V42I2.9321","url":null,"abstract":"Abstrak .  Pemetaan tanah semidetail skala 1:50.000 mengidentifikasi sekurangnya 1.628.485 ha lahan di Sulawesi tanahnya berkembang dari batuan ultrabasik. Permasalahannya adalah tanah-tanah mengandung nikel (Ni) dan kromium (Cr) serta logam berat lainnya dalam konsentrasi tinggi. Kondisi ini dapat meracuni tanaman, yang pada akhirnya membahayakan kesehatan hewan dan manusia. Oleh karena itu sangat penting mengetahui kadar logam berat, terlebih potensi toksiknya terhadap tanaman, dan memberikan arahan pengelolaan untuk pertanian. Sebanyak enam profil terpilih yang berasal dari  Kolaka (Sulawesi Tenggara), Luwu Timur (Sulawesi Selatan) dan Morowali (Sulawesi Tengah) telah dideskripsi, dan 29 contoh tanah yang berasal dari 6 profil (HK-16, UY-16, SL-34, SL-09, RM-07 dan YY-09) telah dianalisis kandungan logam berat, mineralogi (komposisi mineral pasir dan liat), dan sifat kimia tanahnya. Hasil penelitian menunjukkan tanah yang berkembang dari batuan ultrabasik (peridotit dan serpentinit) telah mengalami pelapukan lanjut, ditunjukkan oleh warna tanah merah gelap/maron (hue 2.5YR -10R); mineral pasir didominasi oleh mineral resisten (opak, kuarsa, garnet, enstatit dan khlorit); mineral liat didominasi kaolinit dan goetit ditunjukkan pada puncak difraksi 7.3oA dan 4.15-4.16oA. Kesuburan tanah rendah sampai sangat rendah dicirikan oleh kandungan bahan organik, kadar P2O5 dan K2O potensial dan P-tersedia yang umumnya rendah sampai sangat rendah. Basa-basa dapat ditukar rendah, kecuali Mg2+. KTK-tanah dan KTK-liat rendah ( 1,5 cmol(+)/kg, kecuali profil YY-09 dan SL-34 mempunyai KTK efektif 1.5 cmol (+)/kg, except the YY-09 and SL-34 profiles characterizing the acric properties which have effective-CEC <1.5 cmol (+)kg-1. Very high Ni and Cr concentrations exceeded the safety threshold (70 ppm for Ni and 600-1000 ppm for Cr), 670-1508 ppm and 1230-1829 ppm respectively. The concentration of boron (B) and manganese (Mn) is also very high , especially on the SL-09 profile. Soil pH is 3.9-7.0 and colloidal charges are generally negative, causing Si solubility to be higher than Cr, as a result Ni cations are strongly bound to the surface of soil particles, making them more easily absorbed and poison plants. Therefore, suggestions for soil management to suppress Si solubility are: 1) giving organic matter, 2) planting agricultural lime in the form of CaCO3), and 3) planting crops that are not consumed directly, e.g. forestry crops.","PeriodicalId":165570,"journal":{"name":"Jurnal Tanah dan Iklim","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115480266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pengekstrak, Status dan Dosis Pupuk Kalium untuk Padi Gogo pada Hapludults, Braja Selebah, Kabupaten Lampung Timur ( Status and Dosage of Potassium Fertilizer for Upland Rice in Hapludults, Braja Selebah, East Lampung District )","authors":"A. Kasno, I. W. Suastika","doi":"10.2017/JTI.V41I1.5866","DOIUrl":"https://doi.org/10.2017/JTI.V41I1.5866","url":null,"abstract":"Abstrak : Kalium merupakan hara makro primer dan menjadi faktor pembatas pertumbuhan pada lahan kering masam. Pengekstrak hara K terbaik, status hara K dan dosis pupuk K untuk padi gogo pada Hapludults belum banyak dipelajari. Penelitian bertujuan untuk mendapatkan pengekstrak hara K terbaik, status hara K dan dosis pupuk K untuk tanaman padi gogo yang ditanam pada tanah Hapludults dengan kandungan K sangat rendah. Penelitian dilakukan di Desa Braja Harjosari, Kecamatan Braja Selebah, Lampung Timur (05 o 10’ 57” LS, dan 105 o 46’ 33” BT), pada musim kering 2015 dan musim hujan 2015/2016. Pada musim pertama, status K buatan dibuat dengan menambah pupuk K dengan dosis 0 X, ¼ X, ½ X, ¾ X, dan 1 X, dimana X merupakan jumlah pupuk K untuk mencapai kadar K dalam tanah 0,6 cmol (+) kg -1 . Pada musim kedua dibuat percobaan respon pemupukan pada setiap status hara K, dengan dosis 0, 20, 40, 80, dan 160 kg K ha -1 . Pada musim pertama petak perlakuan berukuran 25 m x 6 m, dan musim kedua 5 m x 6 m. Pengamatan dilakukan terhadap sifat kimia tanah dan berat gabah kering. Pengesktrak K yang diuji adalah NH 4 OAc 1N pH 7, NH 4 OAc 1N pH 4,8, HCl 25%, Truog, Mehlich 1, Bray 1, Bray 2, Colwell, dan Morgan Venema. Hasil penelitian menunjukkan bahwa pengekstrak hara K terbaik tanah Hapludults adalah Colwell. Status hara K rendah, sedang dan tinggi adalah 26,5 mg kg -1 , dan dosis pupuk K untuk padi gogo pada masing-masing status hara K berturut-turut adalah 125, 110, dan 80 kg KCl ha -1 . Abstract. Potassium is a primary macro nutrients and it becomes a limiting factor of plant growth in the upland acid soil. There have not been much studied about the best K extraction, K nutrient status, and the rate of K fertilizer application for upland rice in Hapludults. The objective of this research is to investigate the best extractant for K nutrient, evaluate K nutrient status and the best rate of K fertilizer for each K nutrient status for upland Hapludults with very low K content. The study was conducted in the village of Braja Harjosari, Sub district of Braja Selebah, East Lampung (05 o 10 '57.43 \"S and 105 o 46' 33.27\" E), in dry season of 2015 until the rainy season of 2015/2016. In the first season, a series of artificial K nutrient status from low to high was made by adding K fertilizer with doses of 0 X, ¼ X, ½ X, ¾ X, and 1 X, where X is the amount of K fertilizer intended to achieve the levels of 0.6 cmol (+) kg -1 K in the soil. In the second season, a fertilization response trial on each K nutrient status, with doses of 0, 20, 40, 80, and 160 kg K ha -1 was established Plots dimension was 25 m x 6 m in the first season and 5 m x 6 m in the second season. Observations were made on soil chemical properties and dry grain weight. The K extraction tested were 1N NH 4 OAc pH 7, 1N NH 4 OAc pH 4.8, 25% HCl, Truog, Mehlich 1, Bray 1, Bray 2, Colwell, Morgan Venema. The results showed that the best nutrient K extraction of Hapludults soil was the Colwell. The low, med","PeriodicalId":165570,"journal":{"name":"Jurnal Tanah dan Iklim","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128751896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}