Characterization and Bioassay of Rhizophosphate Bacteria Producing Phytohormone and Organic Acid to Enhance the Maize Seedling Growth

Rhizophosphate bacteria as biofertilizers is a low-cost and environment-friendly fertilizer for improving the nutrients status and fertilizers’ efficiency on degraded agricultural or marginal soils. In this study, the characteristic and performance of selected rhizophosphate bacteria producing phytohormone and organic acid producers was investigated. Soils samples for beneficial rhizobacteria were taken from five maize (Zea mays L.) production area and forest ecosystems in Garut District, West Java Province, Indonesia. The rhizophosphate bacteria were isolated and grown in Pikovskaya medium. Bacterial colonies surrounded by clear zone were isolated and subjected to phosphate solubility and phosphatase activity test followed by bioassay. Based on the phosphatase activity, lactic acid production and indole acetic acid (IAA) production were obtained from three isolates of rhizophosphate. The isolates were identified as Bulkholderia vietnamiensis, Enterobacter ludwigii, and Citrobacter amalonaticus the best of which showed high phosphatase content and production of lactic acid, dissolved P and IAA

Humic Acid for Reducing Carbofuran Content of Rice Grown in Carbofuran-Contaminated Soil

Carbofuran insecticide widely used in rice production. The carbofuran residue in agricultural threatens wide life and human health since its active ingredient carbamate is toxic. Humic acid (HA) amendment is an effective way to minimize the residue in soil since HA can adsorb the organic pollutant and induce growth of fungus that degrade the carbofuran. The objective of this research was to observe the influence of HA on the carbofuran residues in soil, straw, and rice; as well as yield of paddy (Oryza sativa L.) grown in carbofuran contaminated potted soil. The level of carbofuran residue in soil before experiment was 10 mg kg-1. The experiment was setup in Randomized Block Design to test various HAs extracted from organic matter. The results indicated that humic acid didn’t affect plant growth and yield but decreased the carbofuran residue in straw and unhusked rice grain. Rhizosphere of rice treated with HA showed higher fungal count than control. This experiment suggests that HA were effectively used to control the carbofuran residue in soil and rice grown in low carbofuran-contamination agricultural soi

Bioassay of phosphorus solubilizing isolates for enhance P solubility and growth of rice (Oryza sativa L.)

Fosfat merupakan salah satu unsur yang berperan penting bagi pertumbuhan tanaman dan kesuburan tanah. Namun, ketersediaan unsur P terlarut yang dapat diserap oleh tanaman sangat kecil karena berikatan dengan kation yang berada di dalam tanah. Salah satu upaya dalam meningkatkan P tersedia dalam tanah adalah dengan pemanfaatan agen hayati Bakteri Pelarut Fosfat (BPF). Penelitian ini bertujuan untuk menguji isolat BPF yang dapat meningkatkan kelarutan P dan pertumbuhan padi pada uji hayati. Percobaan ini dilaksanakan di Rumah Kaca Departemen Ilmu Tanah dan Sumber Daya Lahan, Fakultas Pertanian, Universitas Padjadjaran. Rancangan percobaan yang digunakan adalah Rancangan Acak Kelompok (RAK) dengan 6 perlakuan dan 5 ulangan. Masing-masing perlakuan jenis bakteri adalah kontrol, Bacillus substilis, B. megatherium, Pseudomonas mallei, Burkholderia sp., dan isolat campuran. Hasil percobaan menunjukkan isolat BPF yang diuji memiliki kemampuan yang bervariasi dalam meningkatkan enzim fosfatase, kelarutan P, dan pertumbuhan padi pada uji hayati. Lebih lanjut, perlakuan BPF campuran memberikan pengaruh lebih baik terhadap aktivitas fosfatase, P terlarut dan pertumbuhan padi dibandingkan isolat tunggal.ABSTRACTPhosphorus is an element that important for soil fertility and plant growth. However, the phosphate nutrient can be uptaken by plants only in a small amount because it binds to cations in the soil. The effort for enhancing the soil P availabilty is by the phosphorus solubilizing bacteria (PSB). This study aimed to test PSB  isolates  for increasing P solubility and rice growth using bioassay. The experiment conducted at the greenhouse in Jatinangor District, Sumedang Regency, West Java with  Randomized Block Design (RBD) for PSB isolates with five replications. Each type of bacteria treatment was control, Bacillus substilis, B. megatherium, Pseudomonas mallei, Burkholderia sp., and mixed isolates. The results showed that the P solubilizing  isolates had various abilities to enhance phosphatase, P solubility, and rice growth using bioassay. Furthermore, the mixed PSB isolates had a better effect on phosphatase activity, dissolved P and rice growth than single isolates

The Application of Phosphate Solubilizing Microbes Biofertilizer to Increase Soil P and Yield of Maize on Ultisols Jatinangor

Ultisols has problems of low availability of nutrients, especially phosphorus. To improve soil phosphate and P fertilizer efficiency, it is necessary to develop biofertilizer such as phosphate solubilizing microbes. Phosphate solubilizing microbes (PSM) have the capability of dissolving soil phosphorus which have been adsorbed and can mineralize organic P to become inorganic P, hence increasing the avalibility of P in the soil. Phosphate solubilizing bacteria (Pseudomonas mallei and Pseudomonas cepacea) and phosphate solubilizing fungi (Penicillium sp. and Aspergillus sp) were selected based on their ability to dissolve P. The experiment was conducted at Jatinangor, West Java Indonesia to study the application of PSM biofertilizer to increase soil P and yield of maize. Experiment used a Randomized Block Design (RBD) in factorial pattern, consisting of two factors with three replications. The first factor consisted of PSM biofertilizer, which were; without PSM, 5 L ha-1 of PSM and 50 kg ha-1 of PSM.  The second factor was P fertilizer with five levels (0%, 25%, 50%, 75% and 100% dosage of recommendation). The results showed that the application of PSM biofertilizer increased soil phosphate and yield of maize on Ultisol Jatinangor.  The dosage of P inorganic fertilizers was reduced by 50%.Keywords: ultisol, maize, biofertillizer, phospate-solubilizing bacteria

Enhancing phosphate availability and growth of C. asiatica in andisols through phosphate-solubilizing bacteria application

Centella asiatica is a medicinal plant containing asiaticoside bioactive, this is considerably higher if grown in the highlands generally on Andisols. Conversely, phosphorus was deficient in Andisol soils. The experiment aimed to study effect of phosphate solubilizing bacteria (PSB) isolates from the rhizosphere of C. asiatica which can dissolve P, produce plant growth promoters, increase growth of C. asiatica and fertilization efficiency. The research was done at Soil Biology Laboratory, Agriculture Faculty, Universitas Padjadjaran and at the experimental field of Agricultural Technology Research and Assessment Installation Manoko, Lembang District, West Java, Indonesia. The research used a factorial randomized block design with three replications and two factors. The first factor were application techniques: control, root soaking, and soil watering. The second factor were dose of NPK fertilizer and soil conditioner: control, P fertilizer dose of 100%, soil conditioner, P fertilizer dose 75% + soil conditioner, and P fertilizer dose of 100% + soil conditioner. Three superior isolates were isolated from C. asiatica rhizosphere and have been identified as: Paraburkholderia caribensis strain MNL-133, Paraburkholderia caribensis strain DSM 13236, and Pseudomonas aeruginosa strain K19PSE24. The results showed that the application of PSB combined with a dose of P fertilizer and soil conditioner on C. asiatica affected the soil P available, the number of leaves, the number of stolons and plant dry weight.ABSTRAKPegagan (Centella asiatica) salah satu komoditas tanaman obat yang memiliki kandungan bioaktif asiatikosida. Asiatikosida lebih tinggi jika ditanam di dataran tinggi umumnya ordo Andisols. Defisiensi hara fosfor salah satu kendala budi daya pada tanah Andisol. Penelitian ini bertujuan mengkaji pengaruh bakteri pelarut fosfat (BPF) unggul yang diisolasi dari roofer tanaman pegagan yang mampu melarutkan P dan menghasilkan pemacu pertumbuhan tanaman pengaruhnya terhadap peningkatan pertumbuhan tanaman pegagan dan efisiensi pemupukan. Penelitian dilaksanakan di Laboratorium Biologi Tanah, Fakultas Pertanian UNPAD dan di kebun percobaan Instalasi Penelitian dan Pengkajian Teknologi Pertanian (IP2TP) Manoko, Lembang menggunakan Rancangan Acak Kelompok Faktorial dengan tiga ulangan. Faktor pertama adalah teknik aplikasi BPF: kontrol; perendaman akar; penyiraman pada tanah. Faktor kedua yaitu dosis pupuk NPK dan pembenah tanah, yaitu perlakuan kontrol, pupuk P dosis 100%, pembenah tanah, pupuk P dosis 75% + pembenah tanah, dan pupuk P dosis 100% + pembenah tanah. Isolasi BPF dari rhizosfer pegagan menghasilkan isolat unggul yaitu Paraburkholderia caribensis strain MNL-133, Paraburkholderia caribensis strain DSM 13236, and Pseudomonas aeruginosa strain K19PSE24. Hasil menunjukkan pemberian BPF dikombinasikan dengan dosis pupuk P dan pembenah tanah pada tanaman pegagan memberikan pengaruh terhadap P tersedia, jumlah daun, jumlah stolon, dan berat kering tanaman

Formulation of Bacillus and Azotobacter Consortia in Liquid Cultures: Preliminary Research on Microbes-Coated Urea

The spore-forming Bacillus and cysts forming Azotobacter are Plant Growth Promoting Rhizobacteria which has been used as biofertilizer in sustainable agriculture since they tolerant to dried soil. Drought resistant microbes will be useful to coat urea in order to reduce the lost of nitrogen. The objectives of this preliminary study were to study the effect of molasse based liquid media on the population of Bacillus spore and Azotobacter vegetative cell and to determine the composition of four bacterial species in liquid formula. In the first experiment The Bacillus subtilis, B. megaterium, A. chroococcum and A. vinelandii were grown separately in 1% cane molasses enriched with 0.1% NH4Cl. As control treatment, The Bacillus and Azotobacter were grown in Nutrient Broth and Ashby’s mannitol broth respectively. In the second experiment, different composition of said Bacillus and Azotobacter were grown in molasses based liquid media prior to count the spore and vegetative cell. The results showed that molasses-based media supported bacterial growth and initial ratio 1:1:1:1 of liquid inoculant was effective to increase bacterial growth. This experiment suggested that the use of organic based media was useful practice of liquid biofertilizer formulation for granule urea coating

APLIKASI PUPUK HAYATI DAN AZOLLA UNTUK MENGURANGI DOSIS PUPUK ANORGANIK DAN MENINGKATKAN N, P, C ORGANIK TANAH, DAN N, P TANAMAN, SERTA HASIL PADI SAWAH

Biofertilizers and Azolla are local potentials sources that can be used for inorganic fertilizers efficiency in increasing crop yields. The purpose of this study was to determine the dose of inorganic fertilizers that can be reduced by the application of biofertilizers and Azolla in lowland rice plants. The aims of study was to determine the increase in N plants, N soil, available P, P uptake, C organic, and the yield of lowland rice. The experiment was carried out at the Experimental Field, Ciparanje, Faculty of Agriculture, Padjadjaran University, in Jatinangor. The treatment in this experiment were A = without the use of fertilizer, B = NPK 100% Fertilizer of recommended dosage, C = 0% NPK + Biofertilizer + Azolla, D = 25% NPK + Biofertilizer + Azolla, E = 50% NPK + Biofertilizer + Azolla, and F = 75% NPK + Biofertilizer + Azolla. The study design used was a Randomized Block Design with four replications. The results showed that biofertilizer and Azolla combined with inorganic fertilizers can enhance total N soil, N plants, P available soil, P uptake of plants, and C organic soil. Application 50% NPK + Azolla + biofertilizer could increased Milled Dry Grain by 10.82% compared to the recommended dosage of inorganic fertilizer (100% NPK) and caould decrease the use of inorganic fertilizer by 50%

The Abilities of Endophytic and Biofertilizing Bacteria and Their Combinations to Suppress Bacterial Wilt Disease (Ralstonia solanacearum) of Chili

Bacterial wilt disease (Ralstonia solanacearum) is one of the most important diseases in Solanaceae, including chili. Biological control is one of environmentally-friendly method for controlling plant diseases. Microbes that are potential as biological control agents include bacterial endophytes and bacteria that are usually used as biofertilizer. This paper discusses the result of the study that examined the abilities of endophytic and biofertilizing bacteria solely or in combination to suppress bacterial wilt disease (R. solanacearum). The endophytic bacteria isolates tested were Lysinibacillus sp. and Bacillus subtilis, while biofertilizing bacteria used were N-fixing bacteria (Azotobacter chrococcum) and P-solubilizing bacteria (Pseudomonas cepacea). The results showed that the endophytic bacteria, biofertilizing bacteria and their combination inhibited wilt disease incidence in chili by 46.7-80 %. The highest disease suppression (80 %) showed by the endophytic bacteria, B. subtilis. This endophyte was also able to promote a significant chili growth. Keywords: Ralstonia solanacearum, Endophytic bacteria, Biofertilizer, Biological control, Chili

Application Technique and Dosage of Halotolerant Nitrogen Biofertilizer for Increasing Soil Total N, N Uptake, Chlorophyll Content, Photosynthate Accumulation and Growth of Rice Plants in Saline Ecosystem

Utilization of halotolerant nitrogen biofertilizer can increase N uptake and promote growth and yield of rice plants in saline ecosystem. Halotolerant nitrogen biofertilizer can be applied to seed and seedling in certain dosage. The aim of this study was to obtain the application technique and dosage that can increase N uptake and promote growth and yield of rice plants in saline ecosystem. The research was conducted in the greenhouse in Kawarang District (Indonesia) from September until November 2020. There was used randomized block design which consisted of two factors with three replications. The first factor was application techniques, i.e. seed treatment, nursery treatment, and seed + nursery treatment. The second factor was dosage of halotolerant nitrogen biofertilizer, i.e. 0, 500, 1,000, 1,500 and 2,000 g ha-1. The results showed that halotolerant nitrogen biofertilizer applied in seed and nursery treatment can increase N uptake and plant height by 3.95 g plant-1 and 34.50 cm, respectively. Dosage of 1,500 g ha-1 can increase the total N of soil (0.26%), chlorophyll content (46.97 SPAD), photosynthate accumulation (3.33 g), and rice yield (13.40 t/ha). Application of halotolerant nitrogen biofertilizer in seed and nursery technique at a dosage of 1,500 g ha-1 can be further recommendation in rice cultivation on saline ecosystems

KETERSEDIAAN DAN SERAPAN P SERTA HASIL JAGUNG MANIS (Zea mays saccharata Sturt.) DENGAN PEMBERIAN PUPUK UREA DAN PK (11:14) PADA INCEPTISOLS DI JATINANGOR

[PHOSPHOROUS AVAILABILITY, ITS UPTAKE AND YIELD OF SWEET CORN UNDER THE APPLICATION OF UREA AND PK FERTILIZERS IN JATINANGOR INCEPTISOLS]. Maize is one of the staple foods cultivated in Indonesia. Low soil fertility causes the low production of maize. Sweet corn requires sufficient nutrients to grow and produce optimally. The application of a combination of Urea fertilizers and PK on sweet corn plants is expected to increase the availability of nutrients and sweet corn crop production. The objective of this study was to determine the effect of Urea fertilizer and PK application on available P, P uptake, and yield of sweet corn (Zea mays saccharata Sturt) on Jatinangor Inceptisols. This research used the Randomized Block Design (RBD) experiment model, consisting of 9 treatments of 1 control treatment (without treatment), 1 standard recommendation of N, P, K fertilizer treatment, and 7 treatments combination of Urea fertilizer and PK. Each treatment was repeated three times. The results revealed that available-P, P uptake, and yield of sweet corn on Jatinangor Inceptisols were affected by the combination of Urea fertilizer and PK. The combination of 300 kg/ha of urea with 215 kg/ha of PK fertilizer increased the available P value until 23,78 ppm, P uptake (0,67 %), and fresh weight of the corncobs (480,27 g plant-1) on Jatinangor Inceptisols.[AVAILABILITY AND ABSORPTION OF PHOSPHOR, AND THE YIELD OF SWEET CORN UNDER THE APPLICATION OF UREA AND PK FERTILIZERS (11:14) IN INCEPTISOL SOIL IN JATINANGOR].  Corn is one of the staple foods cultivated in Indonesia. Low soil fertility causes the low production of maize. Sweet corn requires sufficient nutrients to grow and produce optimally. The application of Urea and PK combinations on sweet corn plants is expected to improve the yield of sweet corn. The objective of this study was to determine the effect of Urea combined with PK fertilizers on the availability of P, P uptake, and yield of sweet corn (Zea mays saccharata Sturt) in Inceptisols in Jatinangor. This research was organized in a Randomized Completely Block Design (RCBD), consisted of 9 treatments of 1 control treatment (without treatment), 1 standard recommendation of N, P, K fertilizer treatment, and 7 treatments combination of Urea fertilizer and PK. Each treatment was repeated three times. The results showed that available-P, P uptake, and yield of sweet corn in Inceptisols were affected by the combination of Urea fertilizer and PK. The combination of 300 kg/ha of urea with 215 kg/ha of PK fertilizer increased the available P until 23,78 ppm, P uptake of 0.67%, and fresh weight of the corn cobs of 480,27 g/plant.