scholarly journals Nitrates as a Potential N Supply for Microbial Ecosystems in a Hyperarid Mars Analog System

Life ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 79
Author(s):  
Jianxun Shen ◽  
Aubrey L. Zerkle ◽  
Eva Stueeken ◽  
Mark W. Claire
Keyword(s):  
Atacama Desert ◽  
Chemical Properties ◽  
Soil Geochemistry ◽  
Shallow Subsurface ◽  
Shock Heating ◽  
N Assimilation ◽  
Mars Analog ◽  
Study Sites ◽  
Nitrate Distribution ◽  
Physical And Chemical

Nitrate is common in Mars sediments owing to long-term atmospheric photolysis, oxidation, and potentially, impact shock heating. The Atacama Desert in Chile, which is the driest region on Earth and rich in nitrate deposits, is used as a Mars analog in this study to explore the potential effects of high nitrate levels on growth of extremophilic ecosystems. Seven study sites sampled across an aridity gradient in the Atacama Desert were categorized into 3 clusters—hyperarid, middle, and arid sites—as defined by essential soil physical and chemical properties. Intriguingly, the distribution of nitrate concentrations in the shallow subsurface suggests that the buildup of nitrate is not solely controlled by precipitation. Correlations of nitrate with SiO2/Al2O3 and grain sizes suggest that sedimentation rates may also be important in controlling nitrate distribution. At arid sites receiving more than 10 mm/yr precipitation, rainfall shows a stronger impact on biomass than nitrate does. However, high nitrate to organic carbon ratios are generally beneficial to N assimilation, as evidenced both by soil geochemistry and enriched culturing experiments. This study suggests that even in the absence of precipitation, nitrate levels on a more recent, hyperarid Mars could be sufficiently high to benefit potentially extant Martian microorganisms.

scholarly journals Atmospheric Nitrate as a Potential Nutrient for Life on Mars

2019 ◽  
Author(s):  
Jianxun Shen ◽  
Aubrey Zerkle ◽  
Mark Claire ◽  
Eva Stueeken
Keyword(s):  
Atacama Desert ◽  
Major Elements ◽  
Soil Geochemistry ◽  
Shallow Subsurface ◽  
N Assimilation ◽  
Life On Mars ◽  
Atmospheric Nitrate ◽  
Study Sites ◽  
Nitrate Distribution

Nitrate is rich in Mars sediments owing to long-term atmospheric photolysis, oxidation, and deposition coupled with a lack of leaching via rainfall. The Atacama Desert in Chile, which is similarly dry and rich in nitrate deposits, is used as a Mars analog in this study to explore the potential effects of high nitrate levels on microbial growth. Seven study sites sampled across an aridity gradient in the Atacama Desert were categorized into 3 clusters – hyperarid, intermediate, and arid sites, as defined by major elements in the regolith, associated biomass, and precipitation. Intriguingly, the distribution of nitrate concentrations in the shallow subsurface suggests that the buildup of nitrate is not solely controlled by precipitation. Correlations of nitrate with SiO2/Al2O3 and grain sizes suggest that sedimentation rates are also important in controlling nitrate distribution. At arid sites receiving more than 10 mm/yr precipitation, rainfall shows a stronger impact on biomass than nitrate does. However, high nitrate to organic carbon ratios are generally beneficial to N assimilation as evidenced both by soil geochemistry and enriched culturing experiments. This study suggests that even in the absence of precipitation on contemporary Mars, the nitrate levels are sufficiently high to benefit potentially extant Martian microorganisms.

scholarly journals Assessment of Degradation Status of Soils in Selected Areas of Ogbomoso, Oyo State, Nigeria

2015 ◽  
Vol 59 ◽  
pp. 17-25
Author(s):  
Esther Abosede Ewetola ◽  
Folasade Mary Owoade ◽  
Olayinka Olakunle Olatunji
Keyword(s):  
Crop Residues ◽  
Sandy Loam ◽  
Chemical Properties ◽  
Conservation Strategies ◽  
Available Phosphorus ◽  
Physical And Chemical Properties ◽  
Surface Sampling ◽  
Study Sites ◽  
Physical And Chemical ◽  
And Chemical Properties

The assessment of degradation status of soils in selected areas of Ogbomoso, Oyo state wascarried out. The soil physical and chemical properties were evaluated using mini pits and surface sampling. The laboratory results obtained were compared with the standard indicators and criteria for land degradation assessment according to FAO, 1979. The results revealed that most of the cultivated parts of the study sites were very highly degraded compared to the soil under vegetative fallow which were moderately degraded. The textural class of the soil ranged from loamy sand to sandy loam. Saturated hydraulic conductivity ranged from 1.54 to 3.4 cm hr-1 corresponding low to moderate permeability. Bulk density ranged from 1.53 to 1.60 g cm-3. Organic matter was very low in all the study sites. Available phosphorus was low in all the locations. Total nitrogen was predominantly low in most of the cultivated and fallow soils. Exchangeable Sodium Percentage (ESP) of the sites depicted that most of the soils were slightly sodic. Summarily, the soil physical and chemical properties status when compared with the FAO standard show that the area either cultivated or fallow is under degradation. In order to optimize crop production in these areas, there may be need to introduce soil conservation strategies. The practice may include use of crop residues, green manure or poultry manure to boost soil fertility. Also regular monitoring of the fertility status of the soils is required.

scholarly journals Assessment of the Impact of Distinct Vineyard Management Practices on Soil Physico-Chemical Properties

2020 ◽  
Vol 13 ◽  
pp. 117862212094484
Author(s):  
Carla SS Ferreira ◽  
Adélcia Veiga ◽  
Ana Caetano ◽  
Oscar Gonzalez-Pelayo ◽  
Anne Karine-Boulet ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Quality ◽  
Management Practices ◽  
Chemical Properties ◽  
Sampling Campaign ◽  
Physico Chemical ◽  
Study Sites ◽  
Wine Region ◽  
Physical And Chemical ◽  
The Impact

Vines are one of the most ancient crops, with great relevance worldwide but especially in wine-growing areas in Southern Europe. In the Bairrada wine region of north-central Portugal, vineyards have long been managed intensively, with frequent tillage and application of fertilizers and phytochemical products. During the last decade, however, these conventional practices are increasingly becoming substituted by more sustainable management practices, in particular integrated production (IP) and, to a lesser degree, no-tillage (NT) and biodynamic (BD). This study investigated differences in soil quality of 4 vineyards managed with each of these practices for at least 6 years. Twelve topsoil (0-15 cm) samples were collected in vineyard rows and inter-rows, during one sampling campaign, and analyzed for selected physical and chemical properties. These physical properties were texture, bulk density and penetration resistance, while the chemical properties included pH, electrical conductivity, and the contents of organic matter, nutrients, cations, and metals. Nearby forest soils were also sampled as a reference, since this was the prior land-use in the study sites. The obtained results demonstrated that conventional practices were associated with diminished soil quality, as indicated by lower contents of organic matter and nutrients, such as total nitrogen (TN) and phosphorus (TP), and exchangeable cations, as well as by a higher concentration of Cu and, in some samples, of Ni and Pb. Cu concentrations were also relatively high under NT, so that overall soil quality, particularly associated with fertility, was best under IP.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Biophysical Measurement of Molecular Weight of Foot-and-Mouth Disease RNA Fragments

1974 ◽  
Vol 32 ◽  
pp. 262-263
Author(s):  
Sydney S. Breese ◽  
Howard L. Bachrach
Keyword(s):  
Chemical Properties ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Distilled Water ◽  
Bovine Plasma ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Carbon Coated ◽  
Rna Fragments ◽  
Physical And Chemical

Continuing studies on the physical and chemical properties of foot-and-mouth disease virus (FMDV) have included electron microscopy of RNA strands released when highly purified virus (1) was dialyzed against demlneralized distilled water. The RNA strands were dried on formvar-carbon coated electron microscope screens pretreated with 0.1% bovine plasma albumin in distilled water. At this low salt concentration the RNA strands were extended and were stained with 1% phosphotungstic acid. Random dispersions of strands were recorded on electron micrographs, enlarged to 30,000 or 40,000 X and the lengths measured with a map-measuring wheel. Figure 1 is a typical micrograph and Fig. 2 shows the distributions of strand lengths for the three major types of FMDV (A119 of 6/9/72; C3-Rezende of 1/5/73; and O1-Brugge of 8/24/73.

Tailoring microstructures of materials through biomimetics

1993 ◽  
Vol 51 ◽  
pp. 500-501
Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Chemical Properties ◽  
Design And Synthesis ◽  
Structure Sensitive ◽  
Macro Scale ◽  
Methods Of Synthesis ◽  
Successive Level ◽  
Engineering Materials ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Synthesis Of Materials

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Chemical Properties ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Physical And Chemical Properties ◽  
Total N ◽  
Randomized Complete Block Design ◽  
Physical And Chemical ◽  
And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

Sign in / Sign up

Export Citation Format

Share Document