Jauhari Syamsiyah

PEMETAAN POTENSI EMISI GRK METANA: SEBAGAI STRATEGI MITIGASI EMISI DAN MENJAGA PRODUKTIVITAS LAHAN PADI SAWAH ORGANIK DI KABUPATEN SRAGEN

Tujuan umum penelitian ini adalah memetakan potensi produksi emisi metana pada lahan sawah organik di Desa Sukorejo dan Jetis, Kecamatan Sambirejo, Sragen, yang dapat digunakan untuk memitigasi emisi metana dan meningkatkan produktivitas lahan. Secara garis besar pelaksanaan penelitian dibagi menjadi 4 tahap ; (1) karakterisasi tanah dan lahan, pengungkapan secara mendalam karakter obyek lahan pada setiap satuan penggunaan lahan sawah, (2) pengukuran potensi produksi emisi metana, dengan metode inkubasi sampel tanah di laboratorium, sampel gas yang dihasilkan dianalisis menggunakan kromatografi gas yang dilengkapi dengan flame ionization detector (FID) untuk menetapkan flux CH 4 , (3) analisa data, taraf perbedaan nilai potensi produksi metana diketahui dengan analisis beda nyata Uji T, dan penentuan faktor yang paling berperan terhadap besarnya potensi emisi metana dengan analisis stepwise regression, dan (4) rekomendasi, pemilihan rekomendasi didasarkan pada praktek budidaya pertanian yang efektif meningkatkan C organik dan menekan produksi emisi metana tanpa mengurangi produktivitas tanaman. Hasil penelitian menunjukkan bahwa ; (1) potensi produksi metana (CH 4 ) berbeda nyata antar satuan penggunaan lahan (SPL) sawah di Desa Sukorejo dan Jetis, (2) iklim, varietas tanaman dan cara budidaya di daerah penelitian tidak signifikan mempengaruhi besarnya potensi produksi metana, dan (3) faktor yang berpengaruh signifikan terhadap besarnya potensi produksi metana di tanah sawah adalah potensial redoks (Eh). Hubungan Eh dengan besarnya potensi produksi metana berkorelasi negatif, artinya penurunan Eh akan menyebabkan peningkatan produksi metana. Mitigasi emisi GRK metana yang dapat dilakukan berdasarkan penelitian ini, bahwa potensial redoks adalah faktor utama penentu potensi produksi metana di dalam tanah sawah, maka alternatif yang memungkinkan adalah dengan pengelolaan air irigasi, yang dalam periode tertentu tanaman padi tidak diairi atau tidak digenangi, atau apabila kondisi air berlebih dilakukan drainase. Usaha ini dilakukan dengan tujuan kondisi tanah tidak terlalu reduktif atau potensial redoks tidak akan turun secara drastis, sehingga akan dapat menghambat aktivitas mikrobia methanogen dalam memproduksi metana.

Pengaruh Bahan Organik dan Pupuk Fosfor terhadap Ketersediaan dan Serapan Fosfor pada Andisols dengan Indikator Tanaman Jagung Manis (Zea mays saccharata strurt)

Title : The Effect of Organic Matter and Phosphor Fertilizer to Availability and Absorption of Phosphor with Sweet Corn Plant ( Zea mays saccharata strurt ) Indicator. This research purposes was to find out the effect of the kinds of organic sources and P fertilizer to the availability and absorption of phosphor in Andisols and to find out kinds of organic sources and P fertilizer dosage that can give the highest of availability and absorption of phosphor in Andisols. This research was conducted in Green House and Chemistry and Soil fertility Laboratory of Agriculture Faculty of Sebelas Maret University from June 2005 until January 2006. This research used Factorial Randomized Complete Design with two factors. The first factor was P0 (without P fertilizer), P1 (100 kg/ha P2O5) and P2 (100 kg/ha P2O5), the second factor consist of B0 (without organic matter), B1 (Gliricida sepium 10 ton/ha), B2 (rice stalk 12 ton/ha) and B3 (manure 14.25 ton/ha). They are 12 treatments that be repeated three times. Data were analyzed with F-test or Kruskal-Wallis test 1% and 5% was used to know the effect of treatment on experimental result. Duncan multiple range test 5% is used for comparing inter-treatment. For finding out the relation between primary dependent variable and secondary dependent one it is used correlation test. The result of research shows that the organic matter and P fertilizer appliances have very significant effects to the availability of phosphor in Andisols and the absorption of P by the plant. The rice stalk appliance 12 ton/ha with P fertilizer 100 kg/ha P2O5 (P2B2) gives the highest availability of phosphor; that is 24.67 mg/kg. The highest absorption of P can be found at the manure appliance 14.25 ton/ha and P fertilizer 100 kg/ha P2O5 (P2B3); that is 2.24 mg. Keywords: Andisols, available-P, organic matter, P fertilizer

Efisiensi Serapan P dan Hasil Tanaman Padi (Oryza Sativa L.) pada Berbagai Imbangan Pupuk Kandang Puyuh dan Pupuk Anorganik di Lahan Sawah Palur Sukoharjo (Musim Tanam II)

Title : Efficiency of P Up Take and The Yield of Rice Plant ( Oryza sativa L.) with Quail Manure and Inorganic Fertilizer at Paddy Soil, Palur, Sukoharjo (Season II). This research was conducted on January-August 2008. Used Randomized Completely Block Design (RCBD) that arranged in factorial with two factors. The first factor was 3 levels of inorganic fertilizer dosage i.e.: without inorganic fertilizer (A1), urea dosage 150 kg.ha-1, SP-36 dosage 75 kg.ha-1, KCl dosage 50 kg.ha-1, and ZA dosage 50 kg.ha-1 (A2), urea dosage 300 kg.ha-1, SP-36 dosage 150 kg.ha-1, KCl dosage 100 kg.ha-1, and ZA dosage 100 kg.ha-1 (A3). And second factor were 3 levels of quail manure dosage i.e.: without quail manure (O1), quail manure dosage 3 Mg.ha-1 (O2); quail manure dosage 6 Mg.ha-1 (O3). Statistical analysis that used was F test or Kruskal-Wallis test, Duncan Multiple Range (DMR) test at 5% in level, and Correlation test. The research result showed that the highest P uptake efficiency, agronomy efficiency, and the grain dry weight was achieved on 50% of inorganic fertilizer recommendation dosage (urea dosage 150 kg.ha-1, SP-36 dosage 75 kg.ha-1, KCl dosage 50 kg.ha-1, and ZA dosage 50 kg.ha-1) and 6 Mg.ha-1of quail manure treatment (A2O3) in mount of 38.83%, 30.40%, and 6.22 Mg.ha-1 respectively. P uptake efficiency in that treatment was increased as much 13.83% than the same treatment in session I. Generally, the grain dry weight on season II lower than season I. The significant decrease in mount of 2,33 Mg/ha-1 found on treatment of inorganic fertilizer present in 50% of recommendation dosage (urea dosage 150 kg.ha-1, SP-36 dosage 75 kg.ha-1, KCl dosage 50 kg. ha-1, and ZA dosage 50 kg.ha-1) and 3 Mg.ha-1 of quail manure treatment (A2O2). Keywords: quail manure, inorganic fertilizer, uptake efficiency, the dry grain weight paddy

Potential Emission Of N2O from Various Types of Soil with Organic Material Addition

N2O is one of the greenhouse gases generated by agricultural activities which is currently highlighted. Amount of N2O is the least amount in the atmosphere, but it has a global warming potential 310 times compared to the global warming potential by CO2, and has a very long half-life time in the atmosphere is about 120-150 years old. Organic fertilization is considered one trigger for N2O emissions, but the other organic materials are needed by the soil as soil-forming material. Intensive research is needed to determine the effect of the organic material to N2O on various aspects including soil type, because Indonesia is rich in soil. Indonesia has 10 of the 12 soil types that exist throughout the world (Soil Taxonomy). This study aims to determine the N2O emissions in different types of soil which were variations of the addition of organic matter. This research was conducted with an experimental method using a completely randomized design.The main observation is the variable potential N2O emissions which analyzed by Soil Incubation method. The results showed variations of provision does not affect the potential of organic materials N2O emissions for 30 days. Soil types of the most releases N2O respectively are Alfisols, then Inseptisols and most minor releases N2O is Andisols.

EVALUASI PENERAPAN PERTANIAN PADI SAWAH SEMI ORGANIK SETELAH MUSIM TANAM V

The study about “Evaluation of semi organic system on rice production at fifth plant season” whose purpose to evaluate the quality and rice yield at semi organic system at fifth plant season, its impact on soil chemistry properties and its properness to farmers. This field experiment has been conducted from May to September 2008 at Palur, Sukoharjo, with two factors. The first factor is anorganic fertilizer at recommendation dose (Urea 300 kg ha -1 , ZA 100 kg ha -1 , SP-36 150 kg ha -1 , KCl 100 kg ha -1 ). The second factor is 30% of dose recommendation anorganic fertilizer (Urea 100 kg ha -1 , ZA 30 kg ha -1 , SP-36 50 kg ha -1 , KCl 30 kg ha -1 ) and five tons organic fertilizer. The data was analyzed with T test to evaluate the differences of semi organic system and anorganic system. The experiment’s result shows that the semi organik system gives weight of dry straw which is higher than anorganic system. The yield of dry unhulled rice in semi organic system(9,2 ton/ha) isn’t significantly different from the weight which is compared with anorganic system (8,576 ton/ha). From the economic analysis, semi organic system gives higher profit than anorganic system. The rice quality (dust and fiber contain) in semi organic system is higher but protein contain isn’t different. Semi organik system gives organik matter contain (1,618%), KPK (14,454 cmol/kg), N total (0,368%), available P (0,368 ppm) and available K (164,96 me%) which is signiificantly higher but givew lower pH (5,5) than anorganic system.