Flooded rice soils of Northern Australia. 1. Changes in salinity

Soil Research ◽  
1972 ◽  
Vol 10 (1) ◽  
pp. 43 ◽  
Author(s):  
BG Williams
Keyword(s):  
Soil Solution ◽  
Specific Conductivity ◽  
Northern Territory ◽  
Soil Profiles ◽  
Northern Australia ◽  
Rice Soils ◽  
Growing Period ◽  
Flooded Rice ◽  
Ion Species ◽  
Total Salinity

Soil salinity, pH, and Eh were determined in two soil types on the Adelaide River plains (Northern Territory) throughout the growing period of a rice crop. Both the total salinity, as indicated by specific conductivity values of the soil solution, and individual ion species were followed at 30 sites in each soil. The results demonstrated the existence of salt gradients within the soil profiles and these gradients, together with the total salt concentration and ion ratios, remained relatively constant throughout the growing season. The results are discussed in terms of experimental methods commonly employed for determining the effects of soil solution properties on rice culture.

Flooded rice soils of Northern Australia. II. Chemical profiles

Soil Research ◽  
1972 ◽  
Vol 10 (1) ◽  
pp. 53
Author(s):  
BG Williams
Keyword(s):  
Carbon Dioxide ◽  
Root Distribution ◽  
Calcareous Soil ◽  
Surface Soil ◽  
Specific Conductivity ◽  
Northern Australia ◽  
Bicarbonate Concentration ◽  
Rice Soils ◽  
Flooded Rice ◽  
Chemical Profiles

Changes in chemical and electrochemical properties of a flooded calcareous soil sown to rice were monitored during the season of flooding. Considerable variations in specific conductivity, individual cation concentrations, bicarbonate concentration, and carbon dioxide pressures were observed within the soil profile to depths of 30 cm. Redox potential and pH tended to be uniform within a profile except when CaSO4 or H2SO4 were added to the surface soil. Both field and pot experiments showed profile variations in soil properties and the significance of this is discussed in terms of the root distribution of rice.

Increased P diffusion as an explanation of increased p availability in flooded rice soils

1976 ◽  
Vol 45 (2) ◽  
pp. 365-377 ◽  
Author(s):  
F. T. Turner ◽  
J. W. Gilliam
Keyword(s):  
P Availability ◽  
Rice Soils ◽  
Flooded Rice ◽  
P Diffusion

scholarly journals Attributes of irrigated rice and soil solution as affected by salinity levels of the water layer

2010 ◽  
Vol 34 (4) ◽  
pp. 1049-1057 ◽  
Author(s):  
Thiago Isquierdo Fraga ◽  
Felipe de Campos Carmona ◽  
Ibanor Anghinoni ◽  
Elio Marcolin
Keyword(s):  
Soil Solution ◽  
Water Layer ◽  
Vegetative Stage ◽  
Patos Lagoon ◽  
Irrigated Rice ◽  
Flooded Rice ◽  
Salinity Levels ◽  
Growth Attributes ◽  
Water Transpiration ◽  
Over Time

In the State of Rio Grande do Sul, Brazil, flooded rice fields using Patos Lagoon as the source of water for irrigation are subject to be damaged by salinity, since this source is bound to the sea on its southern end. The sensitivity of rice is variable during plant development, being higher in the seedling and reproductive periods. However, there is not enough information about the behavior of plants under salt stress during the course of its development, especially in the vegetative stage. This study evaluated the effect of different levels of salinity of irrigation water on the salinity of soil solution over time and on some plant attributes, during the vegetative stage of rice. The study was conducted in a greenhouse, where seeds of the variety IRGA 424 were sown in pots and irrigated with water with electrical conductivity (ECi) levels of: 0.3, 0.75, 1.5, 3.0 and 4.5 dS m-1; from the tillering initiation (V4) until the panicle initiation (PI). The evaluations made were the electrical conductiviy of soil solution (ECe), the dry biomass of plants and stems, tillering, height and the transpiration of plants. The ECe increased with the ECi over time, and was determined by water transpiration flux in pots. The ECe values at the end of the experiment were high and, in most cases, higher than the critical values for flooded rice. The growth attributes of rice were negatively affected from ECi of 2.0 dS m-1 and ECe of 4.0 dS m-1.

Chemical characterisation of deep profile Ferrosols under sugarcane in wet tropical northern Queensland

Soil Research ◽  
2004 ◽  
Vol 42 (1) ◽  
pp. 69 ◽  
Author(s):  
M. J. Donn ◽  
N. W. Menzies ◽  
V. Rasiah
Keyword(s):  
Soil Solution ◽  
Management Practices ◽  
Major Ions ◽  
Chemical Properties ◽  
Soil Profiles ◽  
Current Management ◽  
Selectivity Coefficients ◽  
Deep Profile

The chemical properties of deep profile samples (up to 12 m) of Ferrosols from northern Queensland were investigated to provide an understanding of the accumulation of nitrate (NO3) within these soil profiles. The influence of other cations and anions present in the soil solution or on the exchange and the charge chemistry of the profiles were examined with respect to the NO3 accumulations. The major ions in the soil solution were Na, NO3, and chloride (Cl). Distinct regions of anion accumulation were observed; SO4 accumulated in the upper profile of all cores, whereas NO3 and Cl accumulations were restricted to the lower profile of cores with appreciable AEC (>1�cmolc/kg). Gaines-Thomas selectivity coefficients were used to indicate exchange preference for cations and anions, and are as follows: Al > Ca ~ Mg > K > Na and sulfate (SO4) > Cl ~ NO3. The selectivity of SO4 increased and the extractable SO4 decreased in the lower profile of all cores. This has important implications for the adsorption of NO3 and Cl. The NO3 and Cl accumulations were shown to correspond to a region of low SO4 occupancy of the exchange sites in the lower profile. Along with the high SO4 selectivity, this suggests that SO4 may control the positioning of the NO3 accumulations. It was concluded that the NO3 accumulations were relatively stable under current management practices, although the reduction in NO3 inputs would likely see the gradual replacement of NO3 with Cl as a result of their comparable selectivity for exchange sites.

Parameters of Kava Used as a Challenge to Alcohol

1986 ◽  
Vol 20 (1) ◽  
pp. 70-76 ◽  
Author(s):  
John Cawte
Keyword(s):  
Alcohol Abuse ◽  
Northern Territory ◽  
Clinical Effects ◽  
Pacific Island ◽  
Human Metabolism ◽  
Northern Australia ◽  
Surprising Effect ◽  
Greek Tradition ◽  
High Level

The kava bowl, a traditional feature of Pacific Island societies, has been adopted and adapted by a number of Aboriginal (Yolngu) communities of northern Australia, where it was introduced in the hope that it would challenge alcohol. This paper reports a study of its usage at Elcho Island, Northern Territory. At the high level of intake in this community, medical effects hitherto unreported are being observed. Some, such as a condition of detachment, reminiscent of the archetypal ‘blissful indolence’ of the lotus-eaters of Greek tradition as limned by the poet Homer, are obvious to the lay observer. Other effects are apparently advantageous for the management of alcohol abuse and some forms of psychosis. A surprising effect is the occurrence of a pellagrinous reaction. These observations indicate that further studies of the clinical effects and the human metabolism of high dosage kava are needed. Looming over all are questions of pharmacology. Do the kava pyrones possess anxiolytic or antipsychotic properties? Do they indeed have the property for which Pacific missionaries introduced them to Australia, as an alternative to alcoholism?

A plethora of planigales: genetic variability and cryptic species in a genus of dasyurid marsupials from northern Australia

2016 ◽  
Vol 64 (5) ◽  
pp. 303 ◽  
Author(s):  
Michael Westerman ◽  
Mark J. Blacket ◽  
Ashley Hintz ◽  
Kyle Armstrong ◽  
Patricia A. Woolley ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Nuclear Gene ◽  
Taxonomic Diversity ◽  
Sensu Stricto ◽  
Northern Territory ◽  
Eastern Coast ◽  
Northern Australia ◽  
Gene Sequences ◽  
Geographic Ranges ◽  
Genetic Lineages

Multiple mitochondrial and nuclear gene sequences reveal substantial genetic variation within the dasyurid marsupial genus Planigale, suggesting greater taxonomic diversity than is currently recognised. To further investigate planigale relationships 116 new mitochondrial and nuclear gene sequences, including 16 new specimens, were added to our database. We confirm the presence of an unrecognised species (Planigale ‘species 1’) limited to the Pilbara region of Western Australia and suggest that the ‘Mt Tom Price’ animals may be closely related to Planigale ingrami subtilissima. We also confirm that at least four distinct genetic lineages make up what is currently recognised as P. maculata. This complex of closely related taxa represents a radiation of sibling species rather than a single, genetically diverse one. Three of these lineages (M1 + M2, M3 and M4) are distributed sympatrically across the Top End of Australia and one (M5 = P. maculata sensu stricto) is localised to the eastern coast of Australia. Within the Planigale ingrami complex, Planigale ‘Mt Tom Price’ (lineage Ing. 1) occurs in the Pilbara in sympatry with Planigale ‘species 1’ and lineage Ing. 2 is found in the Northern Territory in sympatry with species of the P. maculata complex. There is thus a plethora of northern Australian planigales, many of which are formally undescribed and whose geographic ranges require careful re-evaluation.

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