Sebastian Margino

Isolation and Selection of Rhizobium Tolerant to Pesticides and Aluminum from Acid Soils in Indonesia

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.

Purification and Characterization of Protease From Bacillus sp. TBRSN- 1

Potato Cyst Nematode (PCN), Globodera rostochiensis, is one of the important potato’s pests and caused economic looses up to 70% in the several centrals of potato plantations in Indonesia. PCN’s shell component of egg shell containing chitin (inner layer) and viteline/ protein (outer layer). The purpose of this research was to purify of protease Bacillus sp. TBRSN-1, isolate from tomato’s rhizosfer in Yogyakarta province. The purifi ed protease could be used for cutting the life cycle of PCN. Results showed that Bacillus sp. TBRSN-1 could produce extracellular protease and purifi cation using DEAE-cellulose ion-exchange chromatography and Sephacryl S-300 gel fi ltration chromatography resulted in specifi c activity 4.31 fold and 1.68% recovery. Analysing using SDS-PAGE 12.5% and molecular weight 48.1 kDa. Km and Vmax values of the protease for casein substrate were 7.83 mg/ml and 4.03 μg/h, respectively. The optimum activity at the temperature 30oC and pH 7.0. Keywords : protease, purifi cation, indigenous Bacillus sp. TBRSN-1

Paraquat Toxicity on Root Nodule Formation on Macroptiliuma tropurpureum Urb. and Its Corelation with Population of Rhizobium sp.

This study was designed to investigate the paraquat toxicity toward root nodulation by Rhizobium on Macroptilium atropurpureum as an indicator plant. The legume was grown in Thornton medium treated with several concentrations of paraquat and inoculated with R.japonicum 143 (Rj-143) or Rhizobium sp. C-1.1. These bacteria represent cross-inoculation of soybean and cover-crops legumes, respectively. Nodule formation and Rhizobium population were measured periodically. At the end of planting time, nitrogenase activity of the nodules was analysis based on ARA (Acethylene Reduction Analysis) method. The results showed that nodules in plants inoculated with Rhizobium without addition paraquat, were formed within four weeks. There was no nodulation when paraquat was added. Paraquat was toxic to the plant, causing chlorosis, stunting, drying of the plant tissues, and death. The symptoms were detected at the second week after planting time. Paraquat also decreased Rhizobium population from 10^6 to 10^2 or 10^1 CFU/mL at 40 and 100 pp, respectively. These results depicted that paraquat disturbed the plant before nodulation, and at the same time Rhizobium populatin decreased until below minimal population required for nodulation. Therefore, the process of nodulation was disturbed, and in some treatments there was nodulation. It was concluded that paraquat was toxic to both plant and the Rhizobium, which cause nodulation failure.

Acceleration of Paraquat Biodegradation by Isolated Soil Bacteria

Herbicides residues were reported to have impact on the ecosystem. It was thought that acceleration of paraquat degradation would minimize these impacts. Paraquat was persistent in peat soil due to low pH. This study was done to investigate the role of bacterial isolates on the acceleration of paraquat degradation, especially in peat soil. The bacteria were isolated from several kinds of Indonesian soils using enrichment culture technique in a modified N-free medium. The medium was added with paraquat at gradually increase-concentration from 10, 20, and 40 ppm (w/w). Examinations in paraquat degradation were done in two levels. The first was in a synthetic medium (N-free medium); the second was in soil extract medium. Two kinds of peat were used to make the soil extract media, i.e. fibric and saphric peat soils. Several bacterial isolates were able to degrade paraquat in N-free medium. However, the degradation mode was different with those in peat soil extract media. None of them degraded paraquat in fibric and saphric soil extract media. It was suggested that the environmental limiting factors were responsible to the failure of paraquat degradation. Two selected isolates were able to degrade paraquat when the pH value of the extract medium was enhanced to around 5.5. Bacterial isolate of SM1, which was isolated from acid sulfate soil of Central Kalimantan, was the best isolate which was able to degrade paraquat in synthetic medium and peat soil extract media, especially in fibric extract medium. It degraded around 30%of paraquat within 15 day. Experiments are being done to enhance paraquat degradation by inoculation of mixed cultures of selected bacterial isolates. Key words: paraquat, degradation, bacterial isolates

Herbisida Parakuat dalam Lahan Gambut: II. Pengaruhnya terhadap Pertumbuhan dan Hasil Kedelai

Utilization of peat soil for agriculture faces several constraints, such as low soil fertility and pH value. No-tillage agricultural system in peat land needs application of herbicides, for example herbicides with paraquat as active agent. This research was conducted to study the influence of paraquat on the growth and yield of soybean in peat. Peat soil from Central Kalimantan Province was obtained for this study. Due to the requirement of the plant, the soil was treated with lime and NPK-fertilizers. The results showed that paraquat significantly inhibited vegetative growth and decreased soybean production. These phenomena were found in early and advanced decomposed peat soil. Enhancement of vegetative growth and yield were detected when peat was treated with lime and or fertilizers. Liming treatment also supported the formation of root nodules. Inspite of increasing the growth of soybean, lime and fertilizers addition in peat was able to neutralize the negative effect of paraquat on the growth and yield of soybean. The best growth and yield of soybean were found in early decomposed peat soil, i.e. fibric peat soil. Key words: paraquat, peat, soybean

Paraquat Herbicide in Peat Soil: I. Its Effects on The Dynamics of Microbial Population

Paraquat has been used widely and periodically in peat soil. It is stable in acid environments, therefore its application in peat soil which represents an acid environment, might prolong its persistence. Liming treatment has known to reduce peat soil acidity. This research was conducted to study the effect of paraquat and liming treatments on the dynamics of microbial population in peat soil. Unlimed and limed peat soil were treated with paraquat to a final concentration of 20 ppm, and incubated for 2 months. Microbiological analysis, consisting of counting of bacterial, actinomycetes, and fungal population were done weekly. The changes of pH value and paraquat residue were also measured. The results showed that in unlimed peat soil, paraquat treatment did not influence microbial population. However, when paraquat was added into limed peat soil, the number of microbial population decreased; especially the population of bacteria. Liming treatment increased bacterial population and changed the population dynamics of actinomycetes. No significant difference of fungal population in peat soil treated with paraquat and lime. Additionally, there was no significant difference in paraquat resistance between limed and unlimed peat soil.