Jaka Widada

The interactive effects of arbuscular mycorrhizal fungi and rhizobacteria on the growth and nutrients uptake of sorghum in acid soil

The inoculation effects of arbuscular mycorrhizal fungi (AMF) or/and rhizobacteria, (phosphate-solubilizing bacteria, PSB; N2-fixing bacteria, NFB; and siderophore-producing bacteria, SPB) on the growth and nutrients uptake of sorghum (Sorghum bicolor) were studied in acid and low availability phosphate soil. The microbial inocula consisted of the AMFs Glomus manihotis and Entrophospora colombiana, PSB Pseudomonas sp., NFB Azospirillum lipoferum, and SPB fluorescent pseudomonad. The inoculation of either AMF or each rhizobacterium improved the plant dry weight and nutrients uptake such as N, P, Fe, and Zn. Dual inoculation of AMF and each rhizobacterium yielded the higher of plant dry weight and nutrients uptake compared to the single inoculation. Dual inoculation of AMF and PSB, AMF and NFB, AMF and SPB increased plant dry weight by 112, 64, and 60 times higher compared to the uninoculated plant, respectively. The rhizobacteria also improved plant colonization by AMF. These results indicated that the interaction of AMF and the selected rhizobacteria has a potential to be developed as biofertilizers in acid soil.

Soil Bacterial Diversity and Productivity of Coffee - Shade Tree Agro-ecosystems

This research was completed using mixed qualitative and quantitative methods. Field surveys were executed in sugar cane plantation throughout South Sulawesi Indonesia. Land suitability analyses were performed using a parametric approach with Storie’s index equation followed up with correlation analysis using the Pearson correlation. Results revealed that the period for sugarcane crop growth in the humid tropic relatively dry regions of South Sulawesi Indonesia lasted for the months of November to July. The land suitability for sugar cane in the research location was moderately suitable (S2c) and marginally suitable (S3c, S3s, S3s,f and S3c,w) with limiting factors such as relative humidity during crop maturation phase, the duration of sunlight, soil depth, soil texture, soil pH and soil drainage. Land suitability index at the research location ranged from 25.2 to 55.0; sugar cane yields ranged from 30.3 to 62.0 Mg ha year. Pearson correlation coefficient (r) between LSI with cane and sugar productivity were 0.81 and 0.84 respectively, signifying the strength of the correlation between the two values. This also indicates that land suitability index can be estimating the potential crop yield in the humid tropicsthat relatively dry climate regions.Field experiment with a split plot design has been carried out in order to assess the growth characteristics and yields, and effectiveness of MVA upland rice which were given potassium fertilizer in two growing seasons. MVA inoculation consisted of three treatments (without MVA, Glomus sp. and Gigaspora sp.) while potassium fertilizer consisted of five levels (0, 12.5, 25, 37.5, and 50 kg ha-1 K). The results showed that plant growth variable which was inoculated by MVA at any levels of K fertilizer was higher in the dry season than that in the wet season, whereas the opposite occurred for net assimilation rate. Potassium content of leaf tissue, shoot/root ratio, and grain weight per hill was determined and mutually dependent on genus MVA, dosages of K fertilizer, and growing season. Harvest index and grain dry weight per hill were influenced by the growing season and the genus MVA but the effect did not depend on each other. At all dosages of K fertilizer and any MVA genera, Gigaspora sp. inoculation was better than that of Glomus sp. Dry weight of grains per hill was affected by the contribution of grain content per hill, weight of 1000 grains and number of productive seedlings per hill. The optimum dosage of K fertilizer in the dry season was 32.4 kg ha-1 K with grain yield 3.12 Mg ha-1 for inoculation of Gigaspora sp., whereas the optimum dosage in the wet season was 34.2 kg ha-1 K for the treatment Glomus sp. inoculation with Gigaspora sp. in the wet season did not reach dosages of optimum K fertilizer. Keywords: Harvest index, MVA, potassium fertilizer, upland rice [ How to Cite : Natawijaya D. 2012. Increasing Growth and Yield of Upland Rice by Application of Vesicular Arbuscular Mycorrhizae and Potassium Fertilizer. J Trop Soils 17 (1): 53-60. doi: 10.5400/jts.2012.17.1.53] [ Permalink/DOI: www.dx.doi.org/10.5400/jts.2012.17.1.53 ]This study aimed to examine Organonitrofos Plus fertilizer (OP) on sweet corn (Zea mays Saccharata L.) and its effect on changes in soil chemical properties of Ultisols. Organonitrofos Plus fertilizer is an enhancement of Organonitrofos fertilizer enriched with microbes at the beginning of the manufacturing process. Research was conducted in the greenhouse of Integrated Agricultural Laboratory of Lampung University. Treatment applied was a factorial of 4 t 2 t 3 with three replications in a randomized block design. The first factor was the dose of OP fertilizer (0, 10, 20, 30 Mg ha-1), the second factor was the dose of inorganic fertilizers (without inorganic fertilizers, and with inorganic fertilizers, namely Urea 0.44, 0.28 SP-36 and KCl 0.16 Mg ha-1), and the third factor was the dose of biochar (0, 10, 20 Mg ha-1). By a single OP fertilizers, inorganic fertilizers, and the interaction between the OP and the inorganic fertilizers increased the weight of dry stover, cob length, cob diameter, cob with husk and cob without husk of corn. OP fertilizers which are applied in Ultisols can improve soil fertility and increase corn production so that OP fertilizer can lessen the use of inorganic fertilizer and can be used as a substitute for inorganic fertilizer. RAE values were highest in treatment of O4K2B2 (30 Mg OP ha-1, with inorganic fertilizer, 10 Mg biochar ha-1) that was equal to 181%, followed by O2K2B3 (10 Mg OP ha-1, with inorganic fertilizer, 20 Mg biochar ha-1 ) with the difference in RAE value of 0.5%.[How to Cite: Dermiyati, SDn Utomo,n KF Hidayat, J Lumbanraja, S Triyono, H Ismono, NEn Ratna, NT Putri dan R Taisa. 2016. Pengujian Pupuk Organonitrofos Plus pada Jagung Manis (Zea mays Saccharata. L) dan Perubahan Sifat Kimia Tanah Ultisols. J Trop Soils 21: 9-17 Doi: 10. 10.5400/jts.2016.21.1.9][Permalink/DOI: www.dx.doi.org/10. 10.5400/jts.2016.21.1.9]Coco rind is a waste that if not used can cause environmental problem around the plantation. One way to utilize cocoa rind is by making it into compost which can be used as organic fertilizer. Different planting distance will affect on the number of plant population per unit area and will indirectly affect the absorption of nutrients, water and other growth factors. The purpose of this study was to determine the effect of the utilization of compost from cacao rind waste on the growth of Saccarum edule Hasskarl plant with different planting distance. The design used was to factor randomized block design with 2 replications, then there are 18 treatment combinations. In this research, the first factor of cacao rind composts comparison with cow manure consisted of three levels, they are: P1 = 50 kg; 10 kg; P2 =50 kg: 30 kg; P3 = 50 kg: 50. While the second factor uses the planting distance which consisted of three levels, they are: J1= 100 cm X 150 cm; J2= 100 cm X 100 cm; J3= 100 cm X 50 cm. Based on the research results, it shows that the best treatment of cocoa rind compost and cow manure, which affects on the number of buds is treatment P3 on 5 WAP, while the best used for the plants’ height is P2 on 3 WAP, and the best used for the leaves’ length is treatment P2 on 2 to 4 WAP.

COMPARATIVE EVALUATION OF CONVENTIONAL VERSUS RAPID METHODS FOR AMPLIFIABLE GENOMIC DNA ISOLATION OF CULTURED Azospirillum sp. JG3

As an initial attempt to reveal genetic information of Azospirillum sp. JG3 strain, which is still absence despite of the strains’ ability in producing valued enzymes, two groups of conventional methods: lysis-enzyme and columnkit; and two rapid methods: thermal disruption and intact colony were evaluated. The aim is to determine the most practical method for obtaining high-grade PCR product using degenerate primers as part of routine-basis protocols for studying the molecular genetics of the Azospirillal bacteria. The evaluation includes the assessment of electrophoresis gel visualization, pellet appearance, preparation time, and PCR result of extracted genomic DNA from each method. Our results confirmed that the conventional methods were more superior to the rapid methods in generating genomic DNA isolates visible on electrophoresis gel. However, modification made in the previously developed DNA isolation protocol giving the simplest and most rapid method of all methods used in this study for extracting PCR-amplifiable DNA of Azospirillum sp. JG3. Intact bacterial cells (intact colony) loaded on electrophoresis gel could present genomic DNA band, but could not be completely amplified by PCR without thermal treatment. It can also be inferred from our result that the 3 to 5-min heating in dH2O step is critical for the pretreatment of colony PCR of Azospirillal cells.

The effect of organic paddy field system to soil properties

This study aims to compare the soil properties among organic paddy field and other cultivation systems. Soil profile description was done to determine the soil horizons. The characteristics of organic paddy soil were better than others as it has C-organic in horizons I and II which were 2.09% and 2.00%, respectively; black soil color in horizon I (10 YR 2/1); microbial biomass C in horizon I and II which were 98.39 ?g C/g soil and 418.01 ?g C/g soil respectively; and microbial biomass N in horizon I and II which were 72.59 ?g N/g soil and 59.11 ?g N/g soil respectively. However, the unfavorable qualities of organic paddy soil including the clay leaching from horizon I (clay 24.56%) to horizon II (clay 40.16%) and high production potential of methane (CH4) (1.81 ?g CH4/kg soil/day and 1.67 ?g CH4/kg soil/day, respectively in horizon I and II) need to be anticipated. The high amount of C-organic in organic paddy field affects the soil color was darker, and the increasing of clay leaching, microbial biomass C and N, and potential of CH4 production.

ISOLASI DAN KARAKTERISASI BAKTERI PENDENITRIFIKASI YANG DIISOLASI DARI LUMPUR KAWASAN MANGROVE

The aim of this research is to isolate denitrifying bacteria which have the highest activity to reduce nitrate. The sources of the denitrifying bacteria were mangrove sediment collected from Cilacap Regency, Central Java and Indramayu Regency, West Java. Basalt medium containing KNO 3 as a source of nitrogen was used for isolating the denitrifying bacteria. Double layer agar was used for making anaerob condition. Fourty-one isolates were obtained at the first step of the isolation, 29 of them have nitrate reduction activity at a range of 0.77-95.62%. Three isolates, i.e. D19.2, DR2.1 and D27.3 having the highest activity were selected for further examination. The selected isolates were characterized and identified. Characterization includes colony and cell morphology, Gram staining, motility, spore staining and biochemical tests as catalase and oxidase. Identification was done by using profile matching to Bergey’s Manual of Determinative Bacteriology. The results indicate that isolate D19.2 and D27.3 have similarities to the characters of genus Listeria , whereas isolate DR2.1 has similarities to the characters of genus Propionibacterium . All of the selected isolates were able to grow in a medium having NaCl concentration at a range of 0.5-3.5% and pH range of 5-8. Observation of nitrate reduction ability of the isolates during five days incubation shows that isolate DR2.1 has the highest denitrifying activity. The selected isolates can be used as bioremediation agents for controlling nitrate pollution in brackish water pond.

ISOLASI, KARAKTERISASI DAN UJI INFEKSI BAKTERI PROTEOLITIK DARI LUMPUR KAWASAN HUTAN BAKAU

This research was aimed to isolate proteolytic bacteria that have high ability to hydrolize protein. The sources of bacterial samples were collected from mangrove sediment in Indramayu and Cilacap Regency. Collwel SWYE Modification Agar medium and Skim Milk Agar Medium, which contain pepton and casein, were used for isolating the bacteria. Forty isolates having proteolitic activity were obtained. Three isolates, i.e. Ps.23.1, Ps.27.3 and Ps.23.2, having the highest activity were selected. The selected isolates were able to grow at pH range of 5 to 8. They were also able to grow at NaCl concentration of 0.5-3.5%. Intramuscular injection test on white shrimp (Lithopenaeus vannamei) shows that Ps.23.1 and Ps.23.2 were not pathogenic to shrimp. On the other hand, Ps.27.3 was indicated to cause disease on shrimp. These results indicated that isolates Ps.23.1 and Ps.23.2 potentially can be used as inoculant for bioremedation of brackish water pond. Isolate Ps.23.1 was characterized to be an aerobic, nonmotile, short rod, gram negative bacteria having catalase and oxidase activities. It produced yellowish, circulair, entire colonies. Isolate Ps.23.2 was characterized to be an aerobic, motile, rod, spore forming, gram positive bacteria having catalase and oxidase activities.