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INDONESIA
Jurnal Tanah dan Iklim
Core Subject : Agriculture,
Jurnal TANAH dan IKLIM memuat hasil-hasil penelitian bidang tanah dan iklim dari para peneliti baik dari dalam maupun dari luar Balai Besar Litbang Sumberdaya Lahan Pertanian. Jurnal ini juga dapat memuat informasi singkat yang berisi tulisan mengenai teknik dan peralatan baru ataupun hasil sementara penelitian tanah dan iklim.
Articles 257 Documents
Teknik Isotop 15N untuk Mengevaluasi Pengaruh Biochar dan Bakteri Penambat Nitrogen terhadap Serapan Nitrogen Tanaman Padi Sawah Taufiq Bachtiar; Nurrobifahmi Nurrobifahmi; Ania Citraresmini; Anggi Nico Flatian
Jurnal Tanah dan Iklim (Indonesian Soil and Climate Journal) Vol 43, No 2 (2019)
Publisher : Balai Besar Penelitian dan Pengembangan Sumberdaya Lahan Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/jti.v43n2.2019.139-145

Abstract

Abstrak.  Penelitian ini dilakukan untuk menguji pengaruh dari biochar yang berasal dari cangkang kelapa sawit dan juga keefektifan bakteri penambat N pada tanaman padi sawah varietas MIRA 1, dengan menggunakan teknik  isotop 15N.  Rancangan penelitian yang digunakan yaitu Rancangan Acak Lengkap dengan 3 ulangan. Perlakuan yang diberikan meliputi K0 = Kontrol; K1 = NPK; B1 = Biochar 2 t ha-1; B2 = Biochar 4 t ha-1; B3 = Biochar 2 t ha-1 + NPK;        B4 = Biochar 4 t ha-1 + ½ NPK; B5 = Biochar 2 t ha-1 + pupuk hayati ABC; B6 = Biochar 4 t ha-1 + pupuk hayati ABC; B7 = Biochar 2 t ha-1 + pupuk hayati ABC + ½ NPK;  B8 = Biochar 4 t ha-1 + pupuk hayati ABC + ½ NPK; B9 = pupuk hayati ABC. Hasil penelitian menunjukkan bahwa pemberian perlakuan B8 (biochar 4 t ha-1 disertai dengan pupuk hayati ABC dan NPK ½ rekomendasi) mampu memberikan nilai serapan N dan hasil tanaman tertinggi. Teknik 15N menunjukan bahwa sumbangan N tertinggi diperoleh dari perlakuan pupuk K1 (pemupukan NPK 100%). Biochar pada sawah memiliki efek pada peningkatan berat kering biji dan jerami, dan jika disertai dengan pupuk hayati, formula ABC + biochar dapat mengurangi penggunaan pupuk NPK hingga 50%.Abstract.  The aim of the research was to assess the impact of biochar derived from coconut shell and the effectivity of nitrogen fixing bacteria for the lowland rice, MIRA 1 variety, by using 15N isotope technique. The research design was complete randomized design with 3 replications. The treatments included: K0 = control; K1 = NPK; B1 = Biochar 2 t ha-1; B2 = Biochar  4 t ha-1; B3 = Biochar  2 t ha-1 + NPK; B4 = Biochar 4 t ha-1 +  ½ NPK; B5 = Biochar 2 t ha-1 + Biofertilizer ABC; B6 = Biochar 4 t ha-1 + Biofertilizer ABC; B7 = Biochar 2 t ha-1 + Biofertilizer ABC + ½ NPK; B8 = Biochar 4 t ha-1 + Biofertilizer ABC + ½ NPK; B9 = Biofertilizer ABC. The result shows that B8 treatment resulted in the highest nitrogen uptake and crop yield. The 15N isotope technique showed that the highest nitrogen supply was derived from K1 treatment (100% NPK fertilizer application. Biochar on paddy fields has an effect on increasing dry weight of grain and dry weight of straw, and if accompanied by biofertilizer of ABC formula + biochar, it can reduce the use of NPK fertilizer by 50%.
Dampak El Nino 2015 terhadap Performa Tanaman Kelapa Sawit di Bagian Selatan Sumatera (Effect of El Nino 2015 on Oil Palm Performance in Southeastern Part of Sumatera) Nuzul Hijri Darlan; Iput Pradiko; Hasril H. Siregar
Jurnal Tanah dan Iklim (Indonesian Soil and Climate Journal) Vol 40, No 2 (2016)
Publisher : Balai Besar Penelitian dan Pengembangan Sumberdaya Lahan Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/jti.v40n2.2016.113-120

Abstract

El Nino 2015 telah menyebabkan kekeringan panjang di wilayah selatan khatulistiwa Indonesia. Kekeringan tersebut juga memicu bencana kebakaran hutan dan lahan yang menyebabkan gangguan asap. Defisit air akibat kemarau panjang dan reduksi radiasi matahari akibat gangguan asap dapat mempengaruhi performa tanaman kelapa sawit. Penelitian ini dilakukan untuk mengetahui dampak El Nino 2015 terhadap kondisi defisit air lahan, deret hari terpanjang tidak hujan (dry spell), dan gangguan asap serta pengaruhnya terhadap performa tanaman kelapa sawit. Penelitian dilakukan menggunakan data curah hujan harian, data lama penyinaran dan visibilitas Januari-Desember 2015 serta data observasi performa tanaman di beberapa kebun kelapa sawit di Sumatera bagian selatan meliputi Riau, Sumatera Barat, Jambi, Bengkulu, Sumatera Selatan dan Lampung. Nilai defisit air dan dry spell pada wilayah kajian berturut-turut berkisar antara 0-624 mm dan 7-133 hari. Disisi lain, gangguan asap yang terjadi selama Juli-Oktober 2015 menyebabkan penurunan lama penyinaran dan visibilitas hingga 70%. Hasil observasi menunjukkan bahwa tanaman mengalami stress akibat kekeringan ditandai munculnya daun tombak, banyak muncul bunga jantan, malformasi tandan, pelepah segar mengalami sengkleh, serta cadangan buah dan bunga yang kurang. Sementara itu, respon tanaman terhadap gangguan asap masih belum diketahu secara jelas, meskipun ada tendensi penurunan rendemen minyak hingga 2% akibat gangguan asap. Upaya teknis yang dapat dilakukan untuk meminimalisasi dampak kekeringan dan gangguan asap adalah melalui penerapan kultur teknis, pemupukan, serta pembuatan sistem konservasi tanah dan air.    Kata kunci : kelapa sawit, El Nino, kekeringan, asap, Sumatera
Pengaruh Abu Dasar (Bottom Ash) dan Kompos Kotoran Sapi terhadap Serapan Hara, Pertumbuhan dan Hasil Tanaman Padi pada Lahan Sawah Bukaan Baru Nurmegawati Nurmegawati; Iskandar Iskandar; Sudarsono Sudarsono
Jurnal Tanah dan Iklim (Indonesian Soil and Climate Journal) Vol 44, No 1 (2020)
Publisher : Balai Besar Penelitian dan Pengembangan Sumberdaya Lahan Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/jti.v44n1.2020.51-60

Abstract

Abstrak. Abu dasar merupakan salah satu bahan potensial yang dapat dimanfaatkan sebagai amelioran untuk memperbaiki kualitas tanah masam. Selain memiliki pH tinggi, jumlah abu dasar melimpah dan belum dimanfaatkan. Tujuan penelitian ini adalah untuk mengkaji pengaruh amelioran abu dasar dan kompos kotoran sapi terhadap serapan hara, pertumbuhan dan hasil tanaman padi pada lahan sawah bukaan baru yang sering mengalami masalah keracunan Fe dan Mn. Penelitian ini dilaksanakan di rumah kaca pada Bulan Agustus 2017 sampai Februari 2018 bertempat di rumah kaca, Balai Penelitian Tanah Laladon Bogor dengan menggunakan Rancangan Acak Lengkap (RAL) pola faktorial dengan 3 ulangan. Faktor pertama adalah empat taraf dosis abu dasar dengan, yaitu 0,1; 2,5 dan 5 t ha-1. Faktor kedua adalah dosis kompos kotoran sapi, yaitu 0,5 dan 10 t ha-1. Contoh tanah yang digunakan untuk percobaan adalah tanah Oxisols lahan kering yang dikondisikan sebagai sawah bukaan baru. Tanaman indikator adalah padi varietas Inpari 33. Parameter yang diamati adalah sifat kimia tanah, kadar unsur hara dalam tanaman dan hasil tanaman. Hasil penelitian menunjukkan pemberian abu dasar hingga 5 t ha-1 dan kompos kotoran sapi hingga 10 t ha-1 tidak berpengaruh nyata terhadap kandungan hara dan serapan hara N, P, K, Fe dan Mn tanaman. Pemberian abu dasar tidak berpengaruh terhadap hasil tanaman padi sedangkan pemberian kompos kotoran sapi 10 t ha-1 mampu meningkatkan berat gabah bernas dan berat kering jerami secara nyata dibanding pemberian kompos kotoran sapi 5 t ha-1. Abstract. Bottom ash is one of the potential materials that can be used as ameliorants to improve the quality of acidic mineral soils. Besides having high pH-value, bottom ash is also abundant in amount and is still untapped. The purpose of this study was to examine the effects of bottom ash and cow manure compost ameliorant on the nutrient uptake, growth and yield of rice plants in a newly open rice field which often shows problems with a high solubility of Fe and Mn. This study was conducted in August 2017 to February 2018 at a greenhouse of Soil Research Institute and was carried out using a completely randomized design (CRD) factorial pattern. The first factor was the dose of bottom ash (0.1, 2.5 and 5 t ha-1) and the second factor was the dose of cow manure compost (0.5 and 10 t ha-1). Each experiment was repeated three times that resulted in 36 experimental pots in total. The soil sample used in this experiment was an Oxisols which was  conditioned as a newly established rice field. The rice variety used was Inpari 33. The parameters observed were soil chemical properties, nutrient content in plants and crop yields. The results showed that bottom ash up to 5 t ha-1 and cow manure compost up to 10 t ha-1 had no significant effect on nutrient content and nutrient uptake of N, P, K, Fe and Mn of plants. Provision of bottom ash does not affect the production of rice plants while the provision of 10 t ha-1 cow manure compost can significantly increase the weight of rice grain and straw dry weight significantly compared to 5 t ha-1 cow manure compost.
Forecasting Model of Rice Production Using Weighted Rainfall Index in Subang, Karawang, and Indramayu Regency . SUTIKNO; R. BOER; A. BEY; K. ANWAR NOTODIPUTRO; I. LAS
Jurnal Tanah dan Iklim (Indonesian Soil and Climate Journal) No 32 (2010): Desember 2010
Publisher : Balai Besar Penelitian dan Pengembangan Sumberdaya Lahan Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/jti.v0n32.2010.%p

Abstract

Various forcasting models of rice production have been developed to support national food security. The forecasting models of national production which use recently have been carried out by the BPS and have not include the climate factors. Whereas, the climate factors influenced the rice’s production. The aim of this research is to develop the harvest area model using independent variables : Weighted Rainfall Index (WRI), SeaSurface Temperature (SST) Nino 3.4, and Dipole Mode Index (DMI). The models which developed was based on BPS models which consist of 3 periods. There are period 1 (January-April), period 2 (May-August), period 3 (September-December).  Furthermore, rice production forecasting is the multiplication of harvest area and yield per ha. Rice production forecasting in one year is sum of the 3 periods. The research location are pantura areas, namely Karawang, Subang, and Indramayu. The result of the research showed that the model performance by WRI for period 2 (May-August) is better than period 1 and period 3. The mean of error for harvest area forecasting for periode 1, 2, and 3 of WRI variable, respectively is 14, 13, and 47%. Based on model validation, harvest area models by independent variable using WRI, SST Nino 3.4, DMI and ratio of harvest area and standard area, relatively have the same performance. One of the reasons is correlation between SST Nino 3.4 and DMI withrainfall is high. Mean of error for rice’s production forecasting of WRI are 13, 15, and 49%, while SST Nino 3.4, DMI, ratio of harvest area and standard area are 29, 12, and 51%. The range of error rice production forecasting at second year are 10-11%.
KARAKTERISTIK MINERALOGI DAN FISIKO-KIMIA TANAH-TANAH DARI ABU VULKANIK DI HALMAHERA, MALUKU UTARA, INDONESIA Suryani, Erna; Hikmatullah, Hikmatullah; Suratman, Suratman
Jurnal Tanah dan Iklim (Indonesian Soil and Climate Journal) Vol 39, No 2 (2015)
Publisher : Balai Besar Penelitian dan Pengembangan Sumberdaya Lahan Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/jti.v39n2.2015.86-98

Abstract

Abstrak. Informasi tentang sifat-sifat tanah dari abu vulkanik di Pulau Halmahera bagian utara Maluku, masih sedikit. Untuk itu sifat morfologi, fisiko-kimia dan mineralogi dari enam profil tanah telah diteliti untuk menentukan jika tanah memenuhi sifat tanah andik. Penelitian dilaksanakan pada tahun 2013-2014. Komposisi mineral pasir ditentukan dengan metode line counting, dan mineral liat dengan X-Ray Difractometer melalui penjenuhan Mg2+. Analisis sifat fisiko-kimia tanah meliputi: tekstur (metode pipet), pH tanah diukur di dalam H2O dan 1 M KCl (rasio tanah dan larutan 1:5); C organik (Walkley and Black); N total (Kjeldahl); P dan K total (ekstraksi HCl 25%), P tersedia (ekstraksi Olsen dan Bray I); Ca, Mg, K, Na dapat tukar dan KTK (ekstraksi NH4OAc pada pH 7,0), kejenuhan basa (persentase jumlah basa-basa); total hara mikro Fe, Mn, Cu, Zn, B, Ni, Cr, dan Mo (ekstrasi HNO3 + HClO4). Hasil penelitian menunjukkan tanah berwarna coklat gelap sampai hitam pada lapisan atas, konsistensi gembur, tekstur sedang dengan kandungan pasir >40%. Mineral pasir didominasi oleh gelas vulkanik, labradorit, bitownit, augit dan hiperstin, sedikit andesin dan olivin yang menunjukkan abu vulkanik bersifat andesit-basalt. Fraksi liat didominasi oleh alofan dan haloisit. Tanah memiliki C organik tinggi (>3,0%) pada lapisan atas dan menurun dengan kedalaman. Reaksi tanah agak masam (pH H2O 6,0-6,5), KTK tanah rendah sampai tinggi (4-29 cmolc kg-1) dan kejenuhan basa tinggi (>35%). Retensi P tinggi (31-78%), demikian juga dengan pH NaF (9,23-10,92). Alo+0,5Feo bervariasi dari 0,32-5,56% dan indeks sifat tanah andik: [%(Alo+0,5Feo) x 15,625 + (% gelas vulkanik)] >36,25. Retensi air pada 1.500 kPa <15%. Lima profil memenuhi sifat tanah andik diklasifikasi sebagai Andisols, dan profil lainnya sebagai Inceptisols. Kelas kesesuaian lahan termasuk sangat sesuai (S1) sampai sesuai marginal (S3) untuk tanaman pangan lahan kering, dengan faktor pembatas KTK rendah di sebagian profil, disamping bahaya erosi pada daerah berlereng >3%. Abstract. Information of soil properties formed on volcanic ashes in the northern Halmahera Island, Maluku, is rather scanty. We studied the morphological, physicho-chemical characteristics and mineralogical of six soil profiles to determine whether these soils meet the andic soil properties. This study was conducted in 2013-2014. Sand mineral composition was determined using line counting, and clay mineral by X-Ray Difractometer with Mg2+saturation. Analysis of physicho-chemical properties are: texture (pipette method), soil pH was measured in H2O and 1 M KCl at a 1:5 soil/solution ratio; organic C (Walkley and Black); total-N (Kjeldahl), total-P and total K (HCl 25% extraction); available-P (Olsen or Bray I extraction), and exchangeable bases and CEC (NH4OAc pH 7.0); base saturation (sum of bases percentage); total-micronutrients Fe, Mn, Cu, Zn, B, Ni, Cr, and Mo (HNO3 + HClO4 extraction). The topsoil was dark brown to black in color, medium texture (sand content > 40%) and friable in consistency. The composition of sand fraction was dominated by volcanic glasses, labradorite, bitownite, augite and hypersthene, with some andesine and olivine, indicating that the volcanic ash has andesit-basaltic properties. The clay fraction dominated by allophane and halloysite. These soils had a high organic C content (> 3.0%) in the topsoil which decreased with depth, slightly acidic in reaction (pH H2O 6.0-6.5), low to high CEC (4-29 cmolc kg-1) and high base saturation (>35%). The P retention was high (31-78%) and so was pH NaF (9.23-10.92). Alo+0.5Feo varied from 0.32-5.56%, and [%(Alo+0.5Feo) x 15.625 + (% volcanic glasses)] was >36.25. Water retention at 1.500 kPa was <15%. Five profiles met the andic soil properties; thus, classified as Andisols, and the rests were classified as Inceptisols. Suitability evaluation showed that the land was very suitable to marginally suitable for upland food crops, whith the low CEC and high erosian hazard on land with slopes >3% as the limiting factors.
THE EFFECT OF P FERTILIZER APPLICATION ON SOIL PHOSPHATE FORM AND CORN YIELD ON TYPIC PLINTUDULTS AND PLACIC PETRAQUEPTS KASNO, ANTONIUS; SUBIKSA, I MADE GUSTI; DWININGSIH, SUTISNI
Jurnal Tanah dan Iklim (Indonesian Soil and Climate Journal) No 29 (2009): Juli 2009
Publisher : Balai Besar Penelitian dan Pengembangan Sumberdaya Lahan Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/jti.v0n29.2009.%p

Abstract

Phosphorus is one of macro nutrient for crops, but on the acid soils it become a main limiting factor for increasing plant growth and yield. Phosphorus availability and forms in the soil are influenced by the level of soil acidity, Fe and Al oxide content and the kind of P fertilizer added on the soil. The objective of this research is to study the effect of three source of P fertilizer application on weight of dry corn and on forms of phosphorus on the soil. The experiment had been conducted on Typic Plintudults in Jagang, North Lampung and on Placic Petraquepts in Cicadas, Bogor. The treatments consist of three source of P fertilizer i.e.:SP-36, DAP, and TSP, and control treatment (without P). The P fertilizer rate is 40 kg ha-1. The results of the study show that the P fertilizer application can increase the dry corn weight from 2 t ha-1 to 6 t ha-1, Al-P from 13 ppm to 41-48 ppm, Fe-P from 176 ppm to 263-300 ppm, Rs-P from 27 ppm to 64-73 ppm, and Ca-P from 14 ppm to 18-34 ppm. The increasing of dry corn weight is influenced by the increasing of Al-P, Rs-P, and Ca-P content on the soils. The increasing weight of dry corn is most influenced by the increasing of Ca-P. Phosphate fertilizer on the Placic Petraquepts Cicadas, Bogor can?t increase weight of dry corn. SP-36 and DAP fertilizer can increase of Al-P and Rs-P, whereas TSP fertilizer decreases of Rs-P and Ca-P. TSP fertilizer is suitable for annual crops, increasing of Ca-P and yield of corn.
POTENSI BAKTERI ASAL TANAH RIZOSFER, SEDIMEN TANAH, DAN PUPUK KANDANG SAPI UNTUK BIODEGRADASI MINYAK BERAT DAN OLI BEKAS Susanti, Winda Ika; Trinanda, Ricky
Jurnal Tanah dan Iklim (Indonesian Soil and Climate Journal) Vol 41, No 1 (2017)
Publisher : Balai Besar Penelitian dan Pengembangan Sumberdaya Lahan Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/jti.v41n1.2017.37-44

Abstract

Abstrak: Penelitian ini bertujuan untuk mendapatkan isolat bakteri dari berbagai lokasi yang berpotensi dalam mendegradasi limbah minyak berat dan oli bekas. Percobaan dilakukan dengan tahapan: mengisolasi bakteri dari sepuluh lokasi pengambilan sampel, melakukan seleksi terhadap kemampuan bakteri dalam mendegradasi minyak berat dan oli bekas pada media minimal cair secara in vitro, mengkarakterisasi fisiologi dan biokimia bakteri, serta melakukan uji Total Petroleum Hydrocarbon (TPH). Diperoleh 5 isolat terpilih yaitu isolat OB3-10% yang diperoleh dari sedimen sungai di daerah Babakan Lebak, OB5-10% dan MB5-5% yang diperoleh dari kotoran sapi kering, OB9-10% yang diperoleh dari tanah rizosfer keladi, dan MB10-10% yang diperoleh dari tanah di sekitar perkebunan sawit. Isolat MB5-5% memiliki kemampuan paling baik dalam menurunkan TPH pada tanah tercemar minyak berat dan isolat OB9-10% memiliki kemampuan paling baik dalam menurunkan TPH pada tanah tercemar oli bekas.Abstract. The objective of this research was to obtain potential bacteria capable to degrade heavy oil and used oil. The research carried out in several steps: isolating bacteria from ten sampling location, selection of bacteria capability to degrade heavy oil and used oil in liquid minimal media, characterizing the physiology and biochemistry of bacteria, testing of Total Petroleum Hydrocarbon (TPH). Five selected isolates was obtained, they were: OB3-10% from Babakan Lebak river sediment, OB5-10% and MB5-5% from dried cow manure, OB9-10% from taro rhisozphere, and MB10-10% from oil palm plantation area. Isolate MB5-5% had the best capability in reducing TPH of heavy oil contaminated soil and isolate OB9-10% had the best capability in reducing TPH of used oil contaminated soil. 
MINERALOGICAL, PHYSICAL, AND CHEMICAL PROPERTIES OF SOILS FROM ANDESITIC VOLCANIC TUFF OF MT. BURANGRANG, WEST JAVA YATNO, EDI; ZAUYAH, S.
Jurnal Tanah dan Iklim (Indonesian Soil and Climate Journal) No 21 (2003): Desember 2003
Publisher : Balai Besar Penelitian dan Pengembangan Sumberdaya Lahan Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/jti.v0n21.2003.%p

Abstract

Information of soils on andesitic volcanic tuff in Indonesia is still limited. Three soil pedons, formed in andesitic volcanic tuff situated in the intensively cultivated vegetable growing areas and secondary forest areas around the Mt. Burangrang, were studied to understand the physical, chemical and mineralogical properties of these soils. All pedons are located in the middle slope with elevation of about 1000 m above sea level (asl). Bulk and undisturbed soil samples of each horizon were analyzed in the laboratory. The results indicated that all the pedons have very deep solum (> 150 cm), granular to subangular blocky structuresand friable to very friable consistences. Mineralogy of the clay fraction of pedons 2 and 3 is dominated by metahalloysite, whereas large amounts of gibbsite are only present in pedon 1. Mineralogical composition of the sand fraction is predominantly composed of opaque minerals, while weatherable minerals such as hornblende, augite, hypersthene and plagioclase (andesine and labradorite) are present in various amounts. Soil bulk density values are generally less than 0.9 mg m-3. Soil reaction is acid to extremely acid, whereas soil pH NaF is of less than 9.4. Aluminum saturation is high in pedon 3 and upper horizons of pedon 1. Organic carbon contents are generally medium in the surface horizons and decrease with depth. Exchangeable bases are dominated by Ca and Mg in medium to very low amounts, cation exchange capacity is medium to high, and base saturation varies ranging from very low to medium. All the pedons studied do not meet the requirements of andic soil properties (P retention of less than 85%), and are classified as Andic Dystrudepts. Thelow bulk density may contribute to the more favourable soil tilth leading to easy tillage and root development. However, high soil acidity in most soils studied is a limiting factor for plant growth.
PERBANDINGAN BERBAGAI TEKNIK ESTIMASI KEBUTUHAN RUANG TERBUKA HIJAU DI KOTA BANDAR LAMPUNG Hesty, Rein Susinda; Gunawan, Andi; Prasetyo, Lilik Budi; Munandar, Aris
Jurnal Tanah dan Iklim (Indonesian Soil and Climate Journal) Vol 43, No 1 (2019)
Publisher : Balai Besar Penelitian dan Pengembangan Sumberdaya Lahan Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/jti.v43n1.2019.59-70

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.
RICE FIELD DISCHARGE MODELLING BY TAKING INTO ACCOUNT THE CONTRIBUTION OF PREVIOUS TERRACE DRAINAGE IRIANTO, GATOT; LAS, IRSAL
Jurnal Tanah dan Iklim (Indonesian Soil and Climate Journal) No 18 (2000): Desember 2000
Publisher : Balai Besar Penelitian dan Pengembangan Sumberdaya Lahan Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/jti.v0n18.2000.%p

Abstract

Its been a long time that paddy terraces have been used in order to modify local hydraulic characteristics, aiming thus at a better evenness in water collecting and distribution. Nevertheless, the quantification of water transfer mechanism in terraces has still to be fully understood. Research on modeling for water transfer has been carried out to answer this issue.The two following reservoir linear laws have been used to represent water transfer in the terrace: (1) taking into account continuous discharge contribution of the precedent terrace and (2) taking into account discontinuous discharge contribution of the precedent terrace. The results of research show that a universal discharge equation for the nth terrace, based on the reservoir linear law derived through inductive method, can be described as:where : Qn is the discharge from the nth terrace (m3/s), Q0 the initial discharge (m3/s), k is a reservoir constant (s-1),and t is the time(s). According to the physical law, the inflow drained from the previous terrace has to be taken into account, but in this case,discharge modeling is reduced to the time when linear reservoir law still applies. This is because time taken for the terrace to be fully drained-dry would be infinite: thus when the water level is under the drain level axis, the linear reservoir law does not apply anymore. At this time, the main part of the stock can not be computed using surface and water level, because of local surface roughness. To find a solution, the debit was modeled byassuming that water on the terrace was fully drained when the water surface reaches exactly half the diameter of the drain pipe. Results of such a model show that the debit thus evaluated approach the debit measured with a coefficient F (criterion of Nash and Sutcliffe) variegating between 0.97 and 0.98. With such results this model can be accepted, assumingas a basic hypothesis that the terrace is dry when water its surface reaches half of the drain pipe diameter.