scholarly journals Epiphytic Cyanobacteria on Chara vulgaris Are the Main Contributors to N2 Fixation in Rice Fields

2004 ◽  
Vol 70 (9) ◽  
pp. 5391-5397 ◽  
Author(s):  
Yoanna Ariosa ◽  
Antonio Quesada ◽  
Juan Aburto ◽  
David Carrasco ◽  
Ramón Carreres ◽  
...  
Keyword(s):  
Rice Field ◽  
Nitrogenase Activity ◽  
Dry Weight ◽  
Rice Fields ◽  
Confocal Scanning Laser Microscopy ◽  
Rice Soil ◽  
Fixation Rate ◽  
Soil System ◽  
Chara Vulgaris ◽  
Rice Plants

ABSTRACT The distribution of nitrogenase activity in the rice-soil system and the possible contribution of epiphytic cyanobacteria on rice plants and other macrophytes to this activity were studied in two locations in the rice fields of Valencia, Spain, in two consecutive crop seasons. The largest proportion of photodependent N2 fixation was associated with the macrophyte Chara vulgaris in both years and at both locations. The nitrogen fixation rate associated with Chara always represented more than 45% of the global nitrogenase activity measured in the rice field. The estimated average N2 fixation rate associated with Chara was 27.53 kg of N ha−1 crop−1. The mean estimated N2 fixation rates for the other parts of the system for all sampling periods were as follows: soil, 4.07 kg of N ha−1 crop−1; submerged parts of rice plants, 3.93 kg of N ha−1 crop−1; and roots, 0.28 kg of N ha−1 crop−1. Micrographic studies revealed the presence of epiphytic cyanobacteria on the surface of Chara. Three-dimensional reconstructions by confocal scanning laser microscopy revealed no cyanobacterial cells inside the Chara structures. Quantification of epiphytic cyanobacteria by image analysis revealed that cyanobacteria were more abundant in nodes than in internodes (on average, cyanobacteria covered 8.4% ± 4.4% and 6.2% ± 5.0% of the surface area in the nodes and internodes, respectively). Epiphytic cyanobacteria were also quantified by using a fluorometer. This made it possible to discriminate which algal groups were the source of chlorophyll a. Chlorophyll a measurements confirmed that cyanobacteria were more abundant in nodes than in internodes (on average, the chlorophyll a concentrations were 17.2 ± 28.0 and 4.0 ± 3.8 μg mg [dry weight] of Chara −1 in the nodes and internodes, respectively). These results indicate that this macrophyte, which is usually considered a weed in the context of rice cultivation, may help maintain soil N fertility in the rice field ecosystem.

scholarly journals Analysis of Reduce Potential Methane Gas Emission by Methanotrofic Bacteria from Rice Field in Gowa

2016 ◽  
Vol 10 (7) ◽  
pp. 183
Author(s):  
Maymuna Nontji ◽  
Baharuddin Patenjengi ◽  
Burhanuddin Rasyid ◽  
Pirman Pirman
Keyword(s):  
Energy Source ◽  
Incubation Period ◽  
Rice Field ◽  
Rice Fields ◽  
Gas Emission ◽  
Gas Emissions ◽  
Gas Concentration ◽  
Methane Gas ◽  
Rice Plants ◽  
Needed Information

<p>The Increase of temperature in atmosphere caused by increasing concentrations of methane in rice field affects to metabolism of rice plants, it can reduce productivity of rice. <em>Methanotrofic</em> bacteria are one of the organisms that can reduce methane gas emissions, because the bacteria use methane as an energy source. Based on the fact, needed information about the reduce potential of methane gas by the bacteria. The aim of this study was to analyze reduce potential of <em>methanotrofic</em> bacteria have been previously isolated that from rice fields in Gowa. The Analysis was done by measuring concentration of methane gas using chromatography gas techniques. Observations of remaining gas concentration were done four times during 13-days incubation period. All isolates were able to reduce methane with varies potential. The highest reduction shown by isolates GMP 2 with the reduction about 88%. The Lowest reduction shown by GMV 3 with the reduction about 51.9%.</p><p><strong>Keywords</strong>: emission, methane, <em>methanotrofic</em></p>

scholarly journals Pengaruh Dosis Herbisida Ethoxysulfuron 15 WG Terhadap Gulma, Pertumbuhan Dan Hasil Tanaman Padi Varietas Ciherang

Agrologia ◽  
2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Dedi Widayat ◽  
Dani Riswandi ◽  
Aty Fujiaty Setiawan
Keyword(s):  
Rice Field ◽  
Block Design ◽  
Rice Fields ◽  
Growth And Yield ◽  
Experimental Result ◽  
Rice Plants ◽  
Randomized Block Design ◽  
Ludwigia Adscendens

Weeds in rice fields decrease the quantity and quality of yield. One of the methods used to control weeds is chemical herbicide. The objective of this research was to find out the effective dosages of herbicide Ethoxysulfuron 15 WG on weeds growth as well as growth and yield of rice plants var. Ciherang. This experiment was used Randomized Block Design with seven treatments and four replication. The Ethoxysulfuron doses trated to rice field  6 g/ha,  9 g/ha, 12 g/ha, 15 g/ha and 18 g/ha. The two control treatments were  mechanical weeding, and without weeding and herbicide. The experimental result showed that Ethoxusylfuron herbicide with the dosage of 9 g/ha could suppress the growth of weed Ludwigia adscendens, Ludwigia perrenis, Fimbristylis miliacea,other weeds, and total weeds and give a good impact on yield of rice plants.

scholarly journals Methane and Carbon Dioxide Flux from Rice Field: Contribution of Environmental Controls

2012 ◽  
Vol 4 (2) ◽  
pp. 1-6
Author(s):  
MB Khan ◽  
S Boult ◽  
P Duy ◽  
E Sharmin ◽  
MA Baten
Keyword(s):  
Production Rate ◽  
Rice Field ◽  
Dry Weight ◽  
Carbon Dioxide Flux ◽  
Gas Production ◽  
In Situ Measurement ◽  
Ex Situ ◽  
Rice Soil ◽  
Rice Soils

An investigation was carried out to quantify the present fluxes of CH4 and CO2 from rice soils and also to investigate the controls on gas production. Soil samples were collected from rice field at Mymensingh, Bangladesh to characterize the samples and for ex-situ measurement. Water content was determined by drying to constant weight at 50°C from rice soils. To determine the organic compound present in rice soil, normal pyrolysis was done. Gasclam® was used to measure the gas concentration from both ex-situ and in-situ measurement. Ex-situ measurement was conducted to measure the gas fluxes from the soil and which was validated by measuring concentration ratios in-situ. Moreover, in-situ measurement was carried out to investigate the influences of controls of environment on gas production and migration. In ex-situ measurement the production rate of CH4 at shallow and deep rice soil was 0.07 mole/tonne dry weight/day and 0.09 mole/tonne dry weight/day, respectively. On the otherhand, the production rate of CO2 in shallow and deep borehole was 0.23 mole/tonne dry weight/day and 0.29 mole/tonne dry weight/day, respectively. In in-situ measurement the average production rate of CH4 in shallow soil was 0.34 % while at deep soil it was very low. The CO2 concentration at shallow and deep soil was 6.37 % and 24.70 %, respectively. The ex-situ measurements of greenhouse gas fluxes are not reliable enough for rice soil as they are invalidated by comparison with concentration ratios of insitu measurements of greenhouse fluxes. There is no strong relationship between atmospheric pressure and patterns of greenhouse gas production in rice soils. Gas concentrations are remarkably constant despite varying pressure. However, the gas production and atmospheric pressure showed fluctuation during the measurement period. There was not enough organic matter in rice soil for detection organic analysis. However in future the organic matter can be extracted and analysed. Key Words: Methane and carbon dioxide flux; Rice field; Environmental controls; Organic analysisDOI: http://dx.doi.org/10.3329/jesnr.v4i2.10123 J. Environ. Sci. & Natural Resources, 4(2): 1-6, 2011

scholarly journals Research trends of microplastics in the soil environment: Comprehensive screening of effects

2021 ◽  
Author(s):  
Shin Woong Kim ◽  
Matthias C. Rillig
Keyword(s):  
Soil Properties ◽  
Additional Data ◽  
Soil Property ◽  
Dry Weight ◽  
Current Data ◽  
Soil Biota ◽  
Soil Parameters ◽  
Soil Environment ◽  
Soil System ◽  
Sensitivity Distribution

AbstractWe collated and synthesized previous studies that reported the impacts of microplastics on soil parameters. The data were classified and integrated to screen for the proportion of significant effects, then we suggest several directions to alleviate the current data limitation in future experiments. We compiled 106 datasets capturing significant effects, which were analyzed in detail. We found that polyethylene and pellets (or powders) were the most frequently used microplastic composition and shape for soil experiments. The significant effects mainly occurred in broad size ranges (0.1–1 mm) at test concentrations of 0.1%–10% based on soil dry weight. Polyvinyl chloride and film induced significant effects at lower concentrations compared to other compositions and shapes, respectively. We adopted a species sensitivity distribution (SSD) and soil property effect distribution (SPED) method using available data from soil biota, and for soil properties and enzymes deemed relevant for microplastic management. The predicted-no-effect-concentration (PNEC)-like values needed to protect 95% of soil biota and soil properties was estimated to be between 520 and 655 mg kg−1. This study was the first to screen microplastic levels with a view toward protecting the soil system. Our results should be regularly updated (e.g., quarterly) with additional data as they become available.

High-temperature-adaptedAzospirillum brasilensestrains: growth and interaction response on associative nitrogen fixation, mineral uptake and yield of cheena (Panicum miliaceumL.) genotypes in calcareous soil

1988 ◽  
Vol 110 (2) ◽  
pp. 321-329 ◽  
Author(s):  
R. Rai
Keyword(s):  
Nitrogen Fixation ◽  
High Temperature ◽  
Calcareous Soil ◽  
Nitrogenase Activity ◽  
Dry Weight ◽  
Cross Resistance ◽  
Mineral Uptake ◽  
Associative Nitrogen Fixation ◽  
Seed Inoculation ◽  
Resistance To Penicillin

SummaryHigh-temperature-adapted strains RAU 1, RAU 2 and RAU 3 ofAzospirillum brasilenseC 7 were isolated from stepwise transfer to higher temperature (30 to 42 °C). One of the strains (RAU 1) showed more growth, greater nitrogenase and hydrogenase activities at 30 and 42 °C than parental and other temperature-adapted strains. This strain also showed growth and more nitrogenase activity from pH 6·5 to 8·0. Strain RAU 1 showed cross-resistance to penicillin (300/µg/ml) but not to streptomycin, kanamycin, viomycin and polymixin B at 30 and 42 °C. It was demonstrated in field plots in calcareous soil that seed inoculation with RAU 1 enhanced mineral uptake of cheena. Inoculation with RAU 1 led to a significant increase in associative nitrogen fixation, dry weight of roots, grain and straw yield of cheena compared with the uninoculated control with or without applied N, but the effect of seed inoculation with high-temperature-adapted strains was variable with different genotypes of cheena.

Integration of the rice field design software with AutoCAD Сivil 3D

2021 ◽  
pp. 347-351
Author(s):  
E.E. Dmitrieva ◽  
E.V. Kalinova
Keyword(s):  
Rice Field ◽  
Field Model ◽  
Rice Fields ◽  
Engineering System ◽  
Design Software

The article discusses the use of AutoCAD Civil 3D engineering system with the software for rice fields designing. The article contains the examples of graphic materials (rice field model) created in AutoCAD Civil 3D based on the design results in RIS software.

scholarly journals Polarisasi etnis dan potensi konflik dalam kebijakan pencetakan sawah baru: Sebuah kajian kepustakaan

2021 ◽  
Vol 16 (1) ◽  
pp. 81
Author(s):  
Dwi Wulan Pujiriyani
Keyword(s):  
Literature Review ◽  
Ethnic Groups ◽  
Ethnic Conflict ◽  
Rice Field ◽  
Aging Population ◽  
Rice Fields ◽  
Ethnic Composition ◽  
Productive Labor ◽  
Potential Problems ◽  
Future Potential

This study aims to analyse the implementation of new rice field plan  policies in Indonesia and their impacts on population and ethnic composition in new rice field locations. This research is conducted by applying a literature review method. It is shown that the implementation of the policies had two major implications. Firstly, it creates assimilation opportunities through collaboration between ethnic migrants and local ethnic groups to work on or cultivate new rice fields. Secondly, the great flows of transmigrants that move to the new rice field locations trigger ethnic polarization, which is prone to cause inter-ethnic conflict. In the future, potential problems associated with the provision of new rice fields are available are the risk of having aging population. The aging population indicates a decrease in productive labor that may also affect on decreasing attractiveness of the rice fields to the younger generation. This situation can lead to the re-involvement of older generation in managing the new rice fields. However, it can raise a new concern on their ability to improve the rice fields’ productivity or, even worse, the new rice fields might be neglected or be sold. 

scholarly journals Potential of Phototrophic Purple Nonsulfur Bacteria to Fix Nitrogen in Rice Fields

2021 ◽  
Vol 10 (1) ◽  
pp. 28
Author(s):  
Isamu Maeda
Keyword(s):  
Nitrogen Fixation ◽  
Regulatory Networks ◽  
Nitrogenase Activity ◽  
Field Studies ◽  
Rice Fields ◽  
Purple Nonsulfur Bacteria ◽  
Available Nitrogen ◽  
Nitrogenase Activities ◽  
Plant Available Nitrogen ◽  
Biological Nitrogen

Biological nitrogen fixation catalyzed by Mo-nitrogenase of symbiotic diazotrophs has attracted interest because its potential to supply plant-available nitrogen offers an alternative way of using chemical fertilizers for sustainable agriculture. Phototrophic purple nonsulfur bacteria (PNSB) diazotrophically grow under light anaerobic conditions and can be isolated from photic and microaerobic zones of rice fields. Therefore, PNSB as asymbiotic diazotrophs contribute to nitrogen fixation in rice fields. An attempt to measure nitrogen in the oxidized surface layer of paddy soil estimates that approximately 6–8 kg N/ha/year might be accumulated by phototrophic microorganisms. Species of PNSB possess one of or both alternative nitrogenases, V-nitrogenase and Fe-nitrogenase, which are found in asymbiotic diazotrophs, in addition to Mo-nitrogenase. The regulatory networks control nitrogenase activity in response to ammonium, molecular oxygen, and light irradiation. Laboratory and field studies have revealed effectiveness of PNSB inoculation to rice cultures on increases of nitrogen gain, plant growth, and/or grain yield. In this review, properties of the nitrogenase isozymes and regulation of nitrogenase activities in PNSB are described, and research challenges and potential of PNSB inoculation to rice cultures are discussed from a viewpoint of their applications as nitrogen biofertilizer.

scholarly journals Cekaman Garam NaCl danTeknik Aplikasi Azolla pada Tanaman Padi

2020 ◽  
Vol 25 (3) ◽  
pp. 349-355
Author(s):  
Fitri Krismiratsih ◽  
Sugeng Winarso ◽  
Slamerto Slamerto
Keyword(s):  
Salt Stress ◽  
Block Design ◽  
Ground Cover ◽  
Dry Weight ◽  
Soil Conditions ◽  
Application Technique ◽  
Rice Plants ◽  
Root Dry Weight ◽  
Randomized Block Design ◽  
Salinity Levels

Efforts to increase production potential can be carried out by extensification in a less productive saline land. Salinity is a major problem in the growth of most plants. Azolla is a plant that is sensitive to salinity, but if it is applied well, it can grow optimally at high salinity levels. The purpose of this study is to obtain an azolla application technique that is effective in increasing the adaptation of rice plants to NaCl saline soil conditions. The experimental design used was Randomized Block Design (RBD) with 2 factors and 3 replications. The first factor was the azolla application technique consisted of 3 levels: fresh azolla composted, fresh azolla immersed, and fresh azolla as a ground cover. The second factor was the levels of NaCl salt stress consisted of 4 levels: control DHL 0, 2, 4, and 8 dS m-1. The adaptation ability of rice plants based on variable plants height growth rate, number of tillers, strove dry weight, root dry weight, stomata density, leaf chlorophyll (SPAD), age of flowering, number of paddy grain, and harvest index. The results showed how to test content up to 2 dS m-1 which increased rice growth especially the application of azolla composted. Increasing stress to 4 and 8 dS m-1showed bad effects on vegetative, physiology, and yields of rice components. The stronger of salt stress the higher all plants growth variables except the age of flowering that actually showed the acceleration of flowering. Application of composted azolla can increase the root dry weight and azolla as a ground cover can increase the numbers of paddy grains.   Keywords: azolla, NaCl, rice, stress

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