Pengaruh Partikel Nano Abu Vulkanik dan Batuan Fosfat terhadap Muatan Variable dan Kemasaman Andisol

ABSTRACTThe effect of particle nano volcanic ash and rock phosphate on variable charge or zero point of charge (pH0) and soil acidity of AndisolsThis experiment aimed to find out the effect of particle nano volcanic ash and rock phosphate on variable charge or zero point of charge (pH0) and soil acidity of Andisols from Ciater Subang-West Java. This experiment was conducted from October 2016 to March 2017 at Soil fertility and Plant Nutrition Laboratory and Physic Soil Laboratory of Soil Science and Land Resources Department, Faculty of Agriculture, Universitas Padjadjaran, Jatinangor. The experiment was arranged in Completely Randomized Design consisted of two factors. The first factor was particle of nano volcanic ash consisted of 4 levels. The second factor was particle of nano rock phosphate consisted of 4 levels and 3 replications. The results showed that there was no interaction between nano particle of volcanic ash and rock on zero point of charge (pH0), but there was interaction effect on pH-H2O. Combination of 2.5% nano particle of volcanic ash and 0% nano particle of rock phosphate could reduce the value of zero point of charge (pH0) as much 28.57%. Combination of 5% volcanic ash nano particle and 7.5% rock phosphate nano particle dosage was the best treatment and could increase the value of soil acidity or pH-H2O until 20.36%.Keywords: Andisol, pHο, Rock phosphate, Volcanic ashABSTRAKTujuan dari penelitian ini adalah untuk mengetahui pengaruh partikel nano abu vulkanik dan batuan fosfat terhadap muatan variable atau titik muatan nol (pH0) dan kemasaman tanah Andisols Ciater Subang-Jawa Barat. Penelitian ini dilaksanakan pada bulan Oktober 2016 sampai dengan Maret 2017 di Laboratorium Kesuburan Tanah dan Nutrisi Tanaman serta Laboratorium Fisika Tanah Departemen Ilmu Tanah dan Sumber Daya Lahan, Fakultas Pertanian, Universitas Padjadjaran, Jatinangor. Penelitian ini menggunakan Rancangan Acak Lengkap pola faktorial dengan dua faktor. Faktor pertama adalah partikel nano abu vulkanik yang terdiri dari 4 taraf. Faktor kedua adalah partikel nano batuan fosfat yang terdiri dari 4 taraf, diulang sebanyak 3 kali. Hasil penelitian menunjukkan bahwa tidak terjadi interaksi antara partikel nano abu vulkanik dan batuan fosfat terhadap titik muatan nol (pH0) namun terjadi interaksi antara kedua perlakuan tersebut terhadap kemasaman tanah (pH-H2O). Komposisi dosis yang paling baik dalam menurunkan pH0 adalah 2,5% partikel nano abu vulkanik dan 0% partikel nano batuan fosfat yaitu sebesar 28,57%, sedangkan komposisi dosis yang paling baik dalam meningkatkan pH-H2O adalah 5% partikel nano abu vulkanik dan 7,5% partikel nano batuan fosfat yaitu sebesar 20,36%.Kata Kunci: Abu vulkanik, Andisol, Batuan fosfat, pH

Proline and Abscisic Acid Content in Droughted Corn Plant Inoculated with Azospirillum sp. and Arbuscular Mycorrhizae Fungi

Plants that undergo drought stress perform a physiological response such as accumulation of proline in the leaves and increased content abscisic acid. A research was conducted to study proline and abscisic acid (ABA) content on drought-stressed corn plant with Azospirillum sp. and arbuscular mycorrhizae fungi (AMF) inoculated at inceptisol soil from Bogor, West Java. The experiments were carried out in a green house from June up to September 2003, using a factorial randomized block design. In pot experiments, two factors were assigned, i.e. inoculation with Azospirillum (0, 0.50, 1.00, 1.50 ml/pot) and inoculation with AMF Glomus manihotis (0, 12.50, 25.00, 37.50 g/pot). The plants were observed during tasseling up to seed filling periods. Results of experiments showed that the interaction between Azospirillum sp. and AMF was synergistically increased proline, however it decreased ABA

EFEK BIOCHAR PADA BERBAGAI PERSENTASE AIR TANAH TERHADAP PERTUMBUHAN DAN HASIL KEDELAI SERTA SIFAT-SIFAT KIMIA TANAH INCEPTISOL

Sifat fisikokimia tanah yang mampu mendukung ketersediaan air selama pertumbuhan tanaman dapat ditingkatkan melalui input komponen organik yang dapat menambah daya pegang air oleh partikel tanah. Penelitian tentang aplikasi biochar pada berbagai persentase air tanah pada Inceptisols asal Jatinangor dilakukan untuk mengamati bagaimana komponen pertumbuhan serta hasil tanaman kedelai (Glycine max L. Merr) kultivar Anjasmoro, kadar air dan bahan organik tanah, kapasitas tukar kation (KTK), konsentrasi dan serapan N, K dipengaruhi oleh kedua perlakuan tersebut. Percobaan dilaksanakan dalam Rumah Plastik Laboratorium Kultur Terkendali, Fakultas Pertanian Universitas Padjadjaran Jatinangor menggunakan Rancangan Acak Kelompok pola faktorial. Dosis biochar sebagai faktor pertama terdiri dari empat taraf (0, 5, 10, dan 15 t ha-1) dan persentase air tanah dari kapasitas lapang (KL) sebagai faktor kedua terdiri dari empat taraf (100, 80, 60 dan 40%) yang diulang tiga kali. Interaksi perlakuan biochar 15 t ha-1 pada kondisi 100% KL berpengaruh nyata terhadap tinggi tanaman, nodula akar, N total dan serapan N serta kadar air tanah pada 6 minggu setelah tanam (MST). Kadar bahan organik tanah dipengaruhi oleh dosis biochar 5–15 t ha-1 dan jumlah daun trifoliat serta bobot kering tanaman pada fase vegetatif akhir dipengaruhi oleh persentase air tanah 60–100% KL. Dosis biochar dan berbagai persentase air tanah tidak berpengaruh nyata terhadap KTK, K-dd dan serapan K

Effect of nanoparticle of volcanic ash and rock phosphate on some soil chemical properties of variable charge Andisols, Indonesia

Andisols is a variable charge soil where fertilizations to the soil do not give the same result as that to the soils with permanent charges. Therefore, amelioration is needed to improve the soil chemical properties. The purpose of this research was to find out the influence of nanoparticles of volcanic ash and rock phosphate as ameliorants on pHw, pH0, P-retention and available P on variable charge Andisols, Indonesia. This research used a complete randomized experimental design on factorial pattern with two factors. The first factor was nanoparticle of volcanic ash consisting of four levels i.e. 0, 2.5, 5.0 and 7.5% of soil weight (w/w). The second factor was nanoparticle rock phosphate, also consisting of 4 levels like nanoparticle of volcanic ash. The treatments were repeated 3 times. The results showed that there was an interaction between nanoparticle of volcanic ash and rock phosphate in increasing pHw to 5.37 and increasing availbale P to 330 mg kg-1. However, there was no interaction in pH0 and P-retention. Nanoparticle of volcanic ash and rock phosphate was found effective to improve some soil chemical properties after one month of incubation

Effect of Azotobacter Application Method on Yield of Soybean (Glycine max (L.) Merill) on Dry Land

Biofertilizer which contain rhizobacteria Azotobacter increase soil fertility and improve plant growth through nitrogen fixation and phytohormone production. The objective of this study was to compare the responses of soybean (Glycine max (L.) Merill) plants in dry land after the application of several Azotobacter inoculation methods. Field experiments were carried out with a randomized block design consisting of five treatments with five replicates each. The treatments were seed inoculation, soil treatment before planting, soil treatment after planting and plant dressing. Plant inoculation with Azotobacter treated with half of recommended dosage urea  while the control plant received recommended dose urea. The experimental results showed that all application methods did not affect soybean production, number of nodules, Azotobacter populations in the rhizosphere and N total soil; but Azotobacter inoculation through leaves increased N uptake and weight of 100 soybean seeds.Pupuk hayati dengan bahan aktif rizobakteri Azotobacter mampu meningkatkan kesuburan tanah dan meningkatkan pertumbuhan tanaman melalui fiksasi nitrogen dan produksi fitohormon. Tujuan penelitian ini adalah membandingkan respons tanaman serkedelai (Glycine max (L.) Merill) di lahan kering setelah aplikasi beberapa metode inokulasi Azotobacter. Percobaan lapangan dilakukan dengan Rancangan Acak Kelompok yang terdiri atas lima perlakuan dan lima ulangan. Perlakuan yang diuji adalah inokulasi benih, inokulasi melalui tanah sebelum tanam, inokulasi melalui tanah setelah tanam dan inokulasi melalui tajuk tanaman.  Pertamanan dengan inokulasi Azotobacter diberi pupuk urea 50 % dari dosis rekomendasi sedangkan tanaman kontrol mendapatkan urea dosis rekomendasi. Hasil percobaan menunjukkan bahwa seluruh metode aplikasi tidak mempengaruhi produksi kedelai, jumlah nodula, populasi Azotobacter di rizosfer dan N total tanah; tetapi aplikasi Azotobacter sp melalui daun meningkatan serapan N dan bobot 100 biji kedelai

Azotobacter Population, Soil Nitrogen and Groundnut Growth in Mercury-contaminated Tailing Inoculated with Azotobacter

Gold mine tailing in Buru island, Maluku Province, Indonesia contains high level of mercury but low in carbon and plant nutrients. Revegetation in such condition needs certain soil treatment which is suitable for plant growth. The objective of pot trials was to study the effect of indigenous Plant Growth Promoting Rhizobacteria Azotobacter and organic matter on bacterial survival as well as growth of groundnut grown in mine tailing. The experimental design was a Split Plot Design which tested three types of Azotobacter liquid inoculant and three soil total organic carbon (TOC) contents. Results showed that Azotobacter inoculation increased Azotobacter population in tailing at the end of vegetative growth of groundnut. Total nitrogen content in soil decreased when TOC level increased. However, nitrogen uptake and growth of groundnut did not change after Azotobacter inoculation or manure amendment. These experiments provided information that Azotobacter inoculation on groundnut maintain its proliferation in Hg-contaminated mine tailing

The Viability of Selected Potassium Solubilizing Rhizobacteria in a Mixture of K-Feldspar and Organic Matter as Carrier Material

The potassium solubilizing biofertilizer based on selected potassium solubilizing bacteria (KSB) can facilitate availability of potassium in primary silicate minerals containing potassium to be absorbed by the plants. The key to successful application of biofertilizer in showing positive effects on inoculated plants is the selection of a carrier material that can guarantee viability of inoculants during shelf life before being applied in the field. The purpose of this study was to determine viability of three selected KSB isolates which were formulated in a mixture of K-feldspar (KF), rice straw compost (RSC), rice husk biochar (RHB), and Aleksandrov liquid medium (ALM) as a carrier material for 24 weeks of shelf life. The experiment used a completely randomized design with nine treatments of carrier material composition and three replications. The results showed formula of potassium solubilizing biofertilizer with a composition of 1% mixed culture KSB + 15% KF + 30% RSC + 45% RHB + 9% ALM was the best formula with high inoculant viability during 4 weeks of shelf life. It was evidenced by the increase in respiration and total KSB population by 17.2% and 213.2%, respectively, compared to formula that produced the lowest respiration and total KSB population