scholarly journals Water track modification of soil ecosystems in the Lake Hoare basin, Taylor Valley, Antarctica

2013 ◽  
Vol 26 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Joseph S. Levy ◽  
Andrew G. Fountain ◽  
Michael N. Gooseff ◽  
J.E. Barrett ◽  
Robert Vantreese ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Salinity ◽  
Shallow Groundwater ◽  
Dry Valleys ◽  
Solute Content ◽  
Ecological Zones ◽  
High Soil Moisture ◽  
Taylor Valley ◽  
High Soil ◽  
Soil Ecosystems

AbstractWater tracks are zones of high soil moisture that route shallow groundwater down-slope, through the active layer and above the ice table. A water track in Taylor Valley, McMurdo Dry Valleys, was analysed for surface hydrogeological, geochemical, and biological characteristics in order to test the hypothesis that water tracks provide spatial structure to Antarctic soil ecosystems by changing the physical conditions in the soil environment within the water tracks from those outside the water tracks. The presence of the water track significantly affected the distribution of biotic and abiotic ecosystem parameters: increasing soil moisture, soil salinity, and soil organic matter within the water track relative to soils outside the water track, and reducing soil phosphate, soil pH, and the population of nematodes and other invertebrates in water track soils relative to off track soils. These results suggest that water tracks are distinct and extreme ecological zones in Taylor Valley that provide long-range (kilometre to multi- kilometre) structure to Antarctic hillslope ecosystems through physical control on soil moisture and solute content. Contrary to expectations, these high soil-moisture sites are not hotspots for faunal biological activity because high soil salinity makes them suitable habitats for only the most halo-tolerant organisms.

scholarly journals White Root Rot of Raspberries

1951 ◽  
Vol 4 (3) ◽  
pp. 211
Author(s):  
GC Wade
Keyword(s):  
Soil Moisture ◽  
Root Rot ◽  
Soil Moisture Content ◽  
Soil Conditions ◽  
Causal Organism ◽  
White Root Rot ◽  
High Soil Moisture ◽  
High Soil ◽  
Soil Temperatures ◽  
Dry Soil

The disease known as white root rot affects raspberries, and to a less extent loganberries, in Victoria. The causal organism is a white, sterile fungus that has not been identified. The disease is favoured by dry soil conditions and high soil temperatures. It spreads externally to the host by means of undifferentiated rhizomorphs; and requires a food base for the establishment of infection. The spread of rhizomorphs through the soil is hindered by high soil moisture content and consequent poor aeration of the soil.

Environment and Chlorsulfuron Phytotoxicity

Weed Science ◽  
1985 ◽  
Vol 33 (3) ◽  
pp. 395-399 ◽  
Author(s):  
John D. Nalewaja ◽  
Zenon Woznica
Keyword(s):  
Soil Moisture ◽  
Soil Nitrogen ◽  
Setaria Viridis ◽  
Kochia Scoparia ◽  
Humidity Effects ◽  
High Soil Moisture ◽  
High Soil ◽  
Green Foxtail ◽  
Temperature And Humidity ◽  
Reduced Toxicity

Glasshouse and growth chamber experiments were conducted to determine chlorsulfuron {2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino] carbonyl] benzenesulfonamide} phytotoxicity to kochia [Kochia scoparia(L.) Schrad. ♯ KCHSC] and green foxtail [Setaria viridis(L.) Beauv. ♯ SETVI] as influenced by temperature and humidity for 1 week after treatment, and by soil moisture and nitrogen. Chlorsulfuron was more phytotoxic to both kochia and green foxtail at 95 to 100% than at 45 to 50% relative humidity for 1 week after treatment whether at 10, 20, or 30 C. Chlorsulfuron phytotoxicity was similar with all posttreatment temperatures at each humidity, except that phytotoxicity was lower at 30 C than at 10 or 20 C at 90 to 100% humidity. Surfactant added to chlorsulfuron exhanced control of kochia more than that of green foxtail and overcame temperature and humidity effects on chlorsulfuron phytotoxicity. A simulated rainfall of 2 mm after chlorsulfuron application reduced toxicity of chlorsulfuron to green foxtail more than to kochia. Chlorsulfuron was more phytotoxic to green foxtail growing with a high than a low soil nitrogen level. High soil moisture following chlorsulfuron application enhanced phytotoxicity to kochia and green foxtail compared to high soil moisture before treatment.

A GREENHOUSE EVALUATION OF THE EFFECTS OF SOIL MOISTURE, RELATIVE HUMIDITY, AND HELMINTHOSPORIUM SATIVUM INFECTION ON BRITTLENESS OF BARLEY AWNS

1964 ◽  
Vol 44 (2) ◽  
pp. 157-160
Author(s):  
R. B. MacLaren ◽  
J. D. E. Sterling
Keyword(s):  
Soil Moisture ◽  
Relative Humidity ◽  
Cell Structure ◽  
Ash Content ◽  
High Relative Humidity ◽  
High Soil Moisture ◽  
High Soil ◽  
Greenhouse Evaluation ◽  
Helminthosporium Sativum

High soil moisture and high relative humidity gave a higher incidence of brittle awns on barley than did restricted soil moisture and low relative humidity. Ash content of awns was highest when soil moisture and relative humidity were maintained at high levels. Helminthosporium sativum (P, K and B) infection reduced awn brittleness of one variety and had no effect on the others.No differences in cell structure of the awns were attributed to treatment.

MICROORGANISMS IN THE ROOT ZONE IN RELATION TO SOIL MOISTURE

1965 ◽  
Vol 11 (3) ◽  
pp. 483-489 ◽  
Author(s):  
E. A. Peterson ◽  
J. W. Rouatt ◽  
H. Katznelson
Keyword(s):  
Soil Moisture ◽  
Soil Moisture Content ◽  
Root Colonization ◽  
Microbial Population ◽  
Root Zone ◽  
Root Surface ◽  
High Soil Moisture ◽  
High Soil ◽  
High Level ◽  
Taxonomic Studies

The influence of soil moisture on the microbial population of rhizosphere soil and of the root surface (rhizoplane) of wheat was studied under controlled conditions. Fertile soil adjusted to 30%, 60%, and 90% of its moisture-holding capacity was used. Bacterial counts and numbers of specific "physiological groups" of bacteria all increased in the rhizosphere and the rhizoplane as soil moisture decreased. Taxonomic studies of the bacteria isolated from the rhizoplane showed a marked preponderance of species of Pseudomonas under conditions of low and intermediate soil moisture content. On the other hand species of Arthrobacter, Bacillus, and Cytophaga dominated the population at high soil moisture. Although the distribution of fungi on the roots was very similar for the low and intermediate moisture levels, there was some restriction of colonization at the high level. Species of Mortierella, Rhizopus, Chaetomium, Curvularia, and Helminthosporium were not represented among isolates from roots at high soil moisture and the relative incidence of species of Fusarium and Phoma decreased. However, high soil moisture favored root colonization by species of Rhizoctonia and sterile dark fungi.

Use of in situ soil moisture network for estimating regional-scale soil moisture during high soil moisture conditions

2015 ◽  
Vol 40 (4) ◽  
pp. 343-351 ◽  
Author(s):  
Tracy Rowlandson ◽  
Sarah Impera ◽  
Jonathon Belanger ◽  
Aaron A. Berg ◽  
Brenda Toth ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Regional Scale ◽  
High Soil Moisture ◽  
High Soil ◽  
Moisture Conditions
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