KAJIAN LAJU INFILTRASI DALAM HUBUNGANNYA DENGAN PERGERAKAN BAHAN LIAT PENYUSUN TUBUH TANAH BERBAHAN INDUK BATU LIAT DAN PASIR

A research about movement of clay materials of soil body compiler through mechanism infiltrate and soils permeability have been conducted. The Result of research show happened movement of clay materials of soil body compiler both of soil parent materials. The maximum rate of infiltration at the soil derived from parent materials of Clay stone reach 8,79 cm / hour and downhill at deepness 52 cm ( BW1 horizon ) with speed 1,71 cm / hour. Referring to that seen rate of infiltration to cause happened movement of clay materials with tendency increase from 33 % at A horizon, increased of become 44 % at Bw1 horizon. While at the soil derived from parent materials of Sand stone that its maximum rate of infiltration reach 8,59 cm / hour and downhill at deepness 145 cm and show the increasing of clays content according to deepness of horizon and soil at Ap horison have 22% of clay and increased of become 50 % at horison 2Bt2 . Key Words : Pergerakan bahan tanah, mekanisme infiltrasi, dan bahan induk tana

Effect of biochar and Tithonia compost on physical properties of post-coal mining soil

Biochar and Tithonia compost are alternative materials used to ameliorate soil properties. The application of these two types of ameliorants in ex-coal mining areas aims to improve the physical properties of the soil and its effect on soybean growth and yield. The research was designed in the form of a polybag experiment conducted in a greenhouse. The soil used for this research was taken from the surface layer of ex-coal mining pits. The treatment levels tested consisted of three biochars and four Tithonia composts. Each treatment level was 0, 5, and 10 t biochar ha-1 and 0, 5, 10, and 15 t Tithonia compost ha-1. The research units were arranged in a completely randomized design. The results showed that applying 10 t biochar ha-1 and 15 t Tithonia compost ha-1 decreased soil bulk density, increased total pore space, aggregate stability, and soil water content capacity, and improved soybean growth and yield. The soil physical properties and soybean improvement were not significantly different from those due to the application of 5 t Tithonia compost ha-1

STUDI PERKEMBANGAN TANAH ABU VULKANIK TOPOSEQUENT GUNUNG MERAPI DAN GUNUNG SINGGALANG

ABSTRACTVolcanic Ash Soil development were studied on toposequent of Gunung Merapi and Gunung Singgalang. Morphological, Chemical and Mineralogical properties of 8 profiles Vulcanic Ash Soil were investigated with different altitude (1100 and 1200 meters ) on each of Gunung Merapi and Gunung Singgalang. Field observation on soil profiles and laboratory data shown that there are different of the soil Colors between Gunung Merapi toposequent and Gunung Singgalang, wich of Gunung Singgalang toposequent more that lights its soil colors. Genetic horizon are more completely on Gunung Singgalang profiles, mean while horizon. thickness, more thick on Gunung Merapi profiles. Short range order mineral transformation on Gunung Singgalang profiles are the degree of haloysite. Heavy mineral content more least on Gunung Singgalang toposequent than Gunung Merapi, mean while weathering index on Gunung Merapi toposequent are bigger. Morphological, chemical and mineralogical characteristic shown that Vulcanic Ash soil of Gunung Singgalang toposequent are more advanced develop than Gunung Merapi toposequen

KAJIAN KANDUNGAN MINERAL ALOFAN DAN FENOMENA FIKSASI FOSFOR PADA ANDISOLS

ABSTRACTResearch on the allophane content on Andisols and phosphorus fixation phenomenon has been conducted in Kerinci District. The existence of Allophane in the soil is inversely proportional to the availability of nutrients, particularly phosphorus, nitrogen, sulfur, and Chlor. All these elements were fixed by clay minerals alofan, in case this element is needed crops.This study aims to: (1) know the level of allophane content in Andisols of Kerinci District, (2) study the phenomenon of fixation of phosphorus in Andisols. This research was conducted using survey method. Determination of the profile and soil sampling conducted at the unit block of land that is set according to landform. Soil samples were taken at depths of 0 -30 cm and 30-60 cm. Soil characteristics were observed Determination of Al, Fe, and Si-amorphous with oxalic acid extraction, amorphous Fe and Al-Na pyrophosphate extraction, C-organic, H and Al-exchangeable, phosphorus retention, pH H2O, pH KCl 1 N , and pH with 5% NaF, Determination of P-available, P-Total, and Determination of K, Ca, Mg, NH4, and NO3 is available. The results showed the amount of allophane content more widely available in 30-60 cm layer (35,20%) with 97.8% phosphorus retention capacity, while in the layer 0-30 cm, there are number of allophane (21,46%) with phosphorus retention capacity 97,7%. P content classified as moderate to high total amount in soils (1.533,33 ppm in a layer of 30-60 cm up to 3.400 ppm in the layer 0-30 cm). Of the total P content in the soil that retention by alofan, soil was still able to provide P-available amount (4,63 ppm in a layer of 30-60 cm to 4,.76 ppm in the layer 0-30 cm)

KAJIAN EFEK RESIDU AMELIORAN IN SITU BATUBARA BITUMINOUS DAN LAPISAN PENGOTORNYA TERHADAP SIFAT FISIKA-KIMIA TANAH REKLAMASI TAMBANG BATUBARA DAN HASIL KEDELAI

Application of slow decomposed organic ameliorants is expected to have a long-term impact on improving soil Physico-chemical properties. The source of in situ organic carbon that is easy to obtain on coal mine reclamation land are the coal itself and its coal impurities (parting) ameliorants. They are slow to decompose, so the residue can last for a long time in the soil. This study aimed to examine the effect of first-year residue of both coal and parting as ameliorants on the improvement of the physical and chemical properties of coal mine reclaimed soil and soybean yields. A pot study was conducted using a randomized block design with 3 treatments. The treatments tested were residues from the first year of the administration of ameliorant in situ, namely: Control, Bituminous coal ameliorant residue, and parting. Both coal and parting were tested with 5 doses each consisting of 5, 10, 15, 20, or 25 tons ha-1. The results showed that the first-year residue of bituminous coal ameliorant and coal impurities significantly affected some of the chemical properties of coal mine reclaimed soil. Both types of ameliorant residues had a very significant effect on increasing C-organic, humic acid, and total N content. The highest increase in soil organic C was found in soil ameliorated by using bituminous coal residues at 25 tons ha-1, and those by using coal impurities at was 20 tons ha-1. However, treatments did not affect soybean growth and yield.    Pemberian amelioran organik yang lambat melapuk ke dalam tanah diharapkan dapat berdampak jangka panjang untuk memperbaiki sifat fisik dan kimia tanah. Sumber karbon organik in situ yang mudah diperoleh pada lahan reklamasi tambang batubara adalah batubara itu sendiri dan lapisan pengotornya. Karbon organik asal batubara dan lapisan pengotornya adalah yang jenis lambat melapuk, sehingga residunya dapat bertahan lama di dalam tanah. Penelitian ini bertujuan untuk mengkaji pengaruh residu tahun pertama amelioran batubara dan lapisan pengotornya terhadap perbaikan sifat fisik dan kimia tanah reklamasi tambang batubara dan hasil kedelai. Penelitian dilakukan dengan menggunakan Rancangan Acak Kelompok (RAK) dengan 3 jenis perlakuan dan percobaan dalam pot. Perlakuan yang dicobakan adalah residu tahun pertama dari pemberian amelioran in situ, yakni: 1) Residu Kontrol (K0), 2) Residu Amelioran Batubara bituminous (C) dan 3) Residu Amelioran Pengotor Batubara (parting) (B). Batubara dan pengotor (parting) batubara keduanya diuji dengan 5 dosis yang masing-masing terdiri dari 5, 10, 15, 20 dan 25 ton/ha. Hasil penelitian menunjukkan bahwa residu tahun pertama amelioran batubara bituminous dan pengotor batubara berpengaruh nyata terhadap beberapa sifat kimia tanah reklamasi tambang batubara. Kedua jenis residu amelioran tersebut berpengaruh sangat nyata dalam meningkatkan C-organik, asam humat dan kandungan N total. Peningkatan C-organik tanah tertinggi oleh ameliorasi residu batubara bituminous terjadi dosis 25 ton/ha (C5), sedangkan pada pengotor batubara dosis 20 ton/ha (B4)