Mosaics of vegetation and soil salinity: a consequence of goose foraging in an arctic salt marsh

1995 ◽  
Vol 73 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Diane S. Srivastava ◽  
R. L. Jefferies
Keyword(s):  
Salt Marsh ◽  
Water Content ◽  
Soil Water ◽  
Surface Sediments ◽  
Plant Biomass ◽  
Hudson Bay ◽  
Upward Movement ◽  
High Biomass ◽  
Lesser Snow Geese ◽  
Evaporative Loss

Grubbing of roots and rhizomes of salt-marsh graminoids by lesser snow geese at La Pérouse Bay, Manitoba, on the Hudson Bay coast, has resulted in a vegetational mosaic. Bare sites, devoid of vegetation, occur adjacent to intact swards (high biomass sites). At some sites destruction of swards is incomplete (low biomass sites). In 1991 and 1992, highest soil salinities occurred in midsummer; surface sediments were flushed of salts by meltwater in spring and by tides in autumn. By late July, in both years, the soil was hypersaline in low biomass and bare sites, unlike that in the high biomass sites. The highest soil salinities were recorded in bare sites, especially in large bare patches. Aboveground plant biomass (g∙m−2) was a much better predictor of the salinity of soil water than the water content or redox potential of soil. Evaporative loss of water from tubes buried in sediments was higher in bare sites compared with that in vegetated sites. Differences in evaporation between sites led to large differences in the salinity of soil water but only small differences in soil water content. The upward movement of salts from buried Tyrell Sea sediments appears responsible for the development of hypersaline conditions. Key words: grubbing, goose grazing, plant biomass, sodium, soil water, hypersalinity.

scholarly journals Glasshouse study of a sprayable, degradable polymer to reduce water use in cotton establishment

Soil Research ◽  
2020 ◽  
Vol 58 (4) ◽  
pp. 379
Author(s):  
Priscilla Johnston ◽  
Michael Braunack ◽  
Philip S. Casey ◽  
Keith L. Bristow ◽  
Raju Adhikari
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Plant Biomass ◽  
Sandy Loam ◽  
Seedling Emergence ◽  
Chemical Properties ◽  
Water Evaporation ◽  
Degradable Polymer ◽  
Extensive Degradation

This glasshouse pot experiment demonstrated that a new sprayable and degradable polymer reduced soil water evaporation and promoted cotton seedling emergence and establishment. The polymer was tested on two contrasting soils (sandy loam and clay), representative of those used to grow cotton in Australia. Changes in soil water content in non-treated and polymer-treated pots were monitored over 80 days, after surface or subsurface watering. Plant biomass, soil water content and soil chemical properties were determined at harvest. The polymer reduced soil water evaporation by up to 35% in sandy loam and up to 20% in clay, did not compromise seedling emergence and improved plant growth per unit water applied by up to 26.2%. The polymer underwent extensive degradation after 80 days to produce low molecular-weight polymers or oligomers and water-extractable silicon species that may have implications for plant nutrition.

scholarly journals Ensuring the effects of climate warming; the sensitivity of controlling factors on soil respiration in Sub-Tropical grassland

2020 ◽  
Vol 7 (3) ◽  
pp. 529-540
Author(s):  
Deepa Dhital ◽  
◽  
Suman Prajapati ◽  
Sanu Raja Maharjan ◽  
Toshiyuki Ohtsuka ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Soil Respiration ◽  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Exponential Function ◽  
Plant Biomass ◽  
Carbon Dioxide Emission ◽  
Tropical Grassland

Prevailing climate change is expected due to carbon dioxide emission to the atmosphere through soil respiration and perhaps the alteration in the terrestrial carbon cycle. The measurements to establish the effect and sensitivity of soil temperature, soil water content and plant biomass on soil respiration was performed in the sub-tropical grassland located in Central Nepal. Field measurements of soil respiration was conducted by using the closed-chamber method, and soil temperature, soil water content and plant biomass were monitored in the years 2015 and 2016. The soil respiration showed positive significant exponential function which accounted for 74.6% (R2=0.746, p<0.05) of its variation with the soil temperature. The temperature sensitivity of soil respiration, Q10 value obtained was 2.68. Similarly, soil respiration showed a positive significant exponential function that accounted for 37.2% (R2=0.372, p<0.05) of its variation with the soil water content. Remarkable seasonal and monthly variations were observed in soil respiration, soil temperature and soil water content, and the plant biomass as well followed the seasonal trend in variation of the soil respiration. Average soil respiration during measurements period was observed 325.51 mg CO2 m-2 h-1 and the annual soil respiration of the grassland in the years 2015 and 2016 was estimated 592.35 g C m-2 y-1. The study confirmed that soil temperature is the most influential primary factor in controlling soil respiration along with the soil water content and plant biomass. This research indicates that through emissions under the increasing temperature and precipitation, in the changing climate, the sub-tropical grassland could be an additional source of carbon dioxide to the atmosphere that might spur risk for further warming.

scholarly journals Soil contribution to CO2 fluxes in Chinampa ecosystems, Mexico

2020 ◽  
Vol 10 ◽  
Author(s):  
Elena Nikolaevna Ikkonen ◽  
Norma Eugenia García-Calderón ◽  
Ervin Stephan-Otto ◽  
Elizabeth Fuentes-Romero ◽  
Abel Ibáñez-Huerta ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Plant Growth ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Seasonal Dynamics ◽  
Plant Biomass ◽  
Vegetation Type ◽  
Ecosystem Carbon ◽  
Dominant Plant Species

Since soil CO<sub>2</sub> flux is a key component of ecosystem carbon balance, quantifying its contribution to the ecosystem carbon flux and understanding the factors that underlie its temporal variation is crucial for a better comprehension of ecosystem carbon dynamics under climate change and for optimal ecosystem use and management. Our objectives were to quantify the contributions of total soil CO<sub>2</sub> efflux (<em>F</em><sub>S</sub>) to ecosystem respiration (<em>R</em><sub>E</sub>) and heterotrophic soil CO<sub>2</sub> efflux (<em>F</em><sub>H</sub>) to <em>F</em><sub>S</sub> in two <em>chinampa</em> ecosystems with different natural grass covers. We also aimed to identify the main environmental drivers of seasonal variability of these contributions. The CO<sub>2</sub> fluxes were measured on each site about every 14 days from September 2008 to August 2009 in the Xochimilco Ecological Park in Mexico City using dark chamber techniques. For two studied sites, <em>R</em><sub>E</sub>,<em> F</em><sub>S</sub> and <em>F</em><sub>H</sub> were estimated on average as 94.1 ± 8.5, 34.7 ± 3.5 and 16.5 ± 1.7 (± S.E.) mg C-CO<sub>2</sub> m<sup>-2</sup> h<sup>-1</sup>, respectively. &nbsp;On average over the study period and sites, the annual cumulative <em>R</em><sub>E</sub>, <em>F</em><sub>S</sub> and <em>F</em><sub>H</sub> fluxes were 824 ± 74, 304 ± 31 and 145 ± 15 g C m<sup>-2</sup> year, respectively. The <em>R</em><sub>E</sub>, <em>F</em><sub>S</sub> and <em>F</em><sub>H</sub> varied between the winter and summer seasons; this variation was explained mostly by seasonal variations of soil temperature, soil water content and shoot plant biomass. Temperature sensitivity of CO<sub>2</sub> fluxes depended on vegetation type and plant growth differences among the sites and decreased in the following order: <em>R</em><sub>E</sub> &gt; <em>R</em><sub>s</sub> &gt; <em>R</em><sub>H</sub>. The contribution of <em>F</em><sub>S</sub> to <em>R</em><sub>E</sub> and <em>F</em><sub>H</sub> to <em>F</em><sub>S</sub> for the two studied sites and period averaged about 38% and 50%, respectively regardless of the site vegetation type, but the degree of <em>F</em><sub>S</sub>/<em>R</em><sub>E</sub> and <em>F</em><sub>H</sub>/<em>F</em><sub>S</sub> variability depended on the differences in seasonal dynamics of plant cover. The contribution of <em>F</em><sub>H </sub>to <em>F</em><sub>S</sub> varied from 37% in summer to 73% in winter at the site without a seasonal shift in dominant plant species, but <em>F</em><sub>H</sub>/<em>F</em><sub>S</sub> was close to constant during the year at the site with a seasonal change in dominant plant species. During the cold period, the contribution of <em>F</em><sub>H </sub>to <em>F</em><sub>S</sub> increased following plant growth decrease. The linear regression analysis showed that plant biomass was the dominant factor controlling the seasonal variation of <em>F</em><sub>H</sub>/<em>F</em><sub>S</sub> ratios, whereas the plant biomass dynamic followed the dynamics of soil water content, water table depth, and soil temperature. Our results suggest that seasonal variation of soil contribution to total fluxes from the <em>chinampa</em> ecosystem is locally differentiated. These differences were related to differences in seasonal dynamics of cover productivity which has been associated with localization of soil water content. This finding has important implications for assessing the contribution of the chinampa ecosystem to the global carbon budget.

One-time application of biosolids to ungrazed semiarid rangelands: 14 yr soil responses

2018 ◽  
Vol 98 (4) ◽  
pp. 696-708 ◽  
Author(s):  
E. Avery ◽  
M. Krzic ◽  
B. Wallace ◽  
R.F. Newman ◽  
S.M. Smukler ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Plant Biomass ◽  
Soil Aggregates ◽  
Mineral Soil ◽  
Total Carbon ◽  
Forage Production ◽  
Soil C ◽  
Biosolids Application

Biosolids have been shown to improve forage production and soil quality on semiarid rangelands in the short term, but less is known about longer-term impacts of one-time biosolids applications. The objective of this study was to determine the effects of a single, surface biosolids application (at 20 dry Mg ha−1) on stability of soil aggregates, bulk density, total carbon (C) and nitrogen (N), permanganate-oxidizable carbon (POXC), polysaccharides, pH, nutrient availability, and soil water content (all at 0–7.5 cm depth) 14 yr following application to ungrazed rangelands in the Central interior of British Columbia. Fourteen years following the biosolids application, aboveground plant biomass was almost two times greater with biosolids application than on control, while exposed mineral soil and microbiotic crust significantly decreased in biosolids plots. Despite differences in aboveground biomass, there was no difference in total soil C and N, POXC, and polysaccharides between biosolids and control plots. Biosolids-amended soil did exhibit significantly greater mean weight diameter of water-stable aggregates, lower pH, increased spring soil water content, and increased availability of Fe3+, Zn2+, Cu2+, and phosphate ions. These findings indicate that the long-term improvements to soil on ungrazed rangeland are possible even from a single biosolids application.

SOIL WATER CONTENT AFFECTS THE AVAILABILITY OF PHOSPHATE

1985 ◽  
pp. 185-189
Author(s):  
M.C.H.Mouat Pieter Nes
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Solution ◽  
Equivalent Reduction

Reduction in water content of a soil increased the concentration of ammonium and nitrate in solution, but had no effect on the concentration of phosphate. The corresponding reduction in the quantity of phosphate in solution caused an equivalent reduction in the response of ryegrass to applied phosphate. Keywords: soil solution, soil water content, phosphate, ryegrass, nutrition.

Effect of inter-row cultivation on soil carbon dioxide emission in a peach plantation

2010 ◽  
Vol 59 (1) ◽  
pp. 157-164 ◽  
Author(s):  
E. Tóth ◽  
Cs. Farkas
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Carbon Dioxide Emission ◽  
Nutrient Content ◽  
Soil Disturbance ◽  
Biological Properties ◽  
Soil Tillage ◽  
Favourable Effect ◽  
Volumetric Soil Water Content

Soil biological properties and CO2emission were compared in undisturbed grass and regularly disked rows of a peach plantation. Higher nutrient content and biological activity were found in the undisturbed, grass-covered rows. Significantly higher CO2fluxes were measured in this treatment at almost all the measurement times, in all the soil water content ranges, except the one in which the volumetric soil water content was higher than 45%. The obtained results indicated that in addition to the favourable effect of soil tillage on soil aeration, regular soil disturbance reduces soil microbial activity and soil CO2emission.

Evaluation of a Multi-Rod Probe Performance for Accurate Measurements of Soil Water Content

2020 ◽  
Author(s):  
Justyna Szerement ◽  
Aleksandra Woszczyk ◽  
Agnieszka Szyplowska ◽  
Marcin Kafarski ◽  
Arkadiusz Lewandowski ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content

Effects of soil water content and temperature on Bt protein degradation in leaves at thinning stage and buds of Bt cotton

2014 ◽  
Vol 22 (3) ◽  
pp. 300-307
Author(s):  
Meijun ZHANG ◽  
Wude YANG ◽  
Meichen FENG ◽  
Yun DUAN ◽  
Mingming TANG ◽  
...  
Keyword(s):  
Protein Degradation ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Bt Cotton ◽  
Bt Protein
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