SOIL MOISTURE VARIATIONS UNDER RURAL SURFACE COVERS AT ELLERSLIE, ALBERTA

1980 ◽  
Vol 60 (4) ◽  
pp. 613-623
Author(s):  
STEWART J. COHEN
Keyword(s):  
Soil Moisture ◽  
Water Use ◽  
Soil Moisture Content ◽  
Stand Density ◽  
Growing Season ◽  
Land Uses ◽  
Rural Land ◽  
University Of Alberta ◽  
A Site ◽  
The University

This study examines the effects of rural land uses on soil moisture and soil water use, the latter expressed in terms of vertical latent heat flux (LE). The field program took place during the 1976 growing season, utilizing a site at the University of Alberta Farm at Ellerslic, Alberta. The site contained several different rural surface plots, identically exposed to prevailing weather, thereby permitting direct comparisons of differences in soil moisture and LE between these plots. Thus, the effects of the surface cover were isolated from those of location. It was found that significant differences in soil moisture content had developed, despite the small sizes of the plots. Some generalizations appearing in the literature were evaluated, and several qualifications were found to be necessary, particularly in reference to the influence of stand density and plant activity on water use.

The effects of burning on Festuca hallii in the parklands of central Alberta

1995 ◽  
Vol 73 (6) ◽  
pp. 937-942 ◽  
Author(s):  
Heather Sinton Gerling ◽  
Arthur W. Bailey ◽  
Walter D. Willms
Keyword(s):  
Standing Crop ◽  
Growing Season ◽  
Early Spring ◽  
Leaf Length ◽  
Tiller Number ◽  
Phenological Stages ◽  
University Of Alberta ◽  
Festuca Hallii ◽  
Tiller Density ◽  
The University

The response of Festuca hallii (Vassey) Piper to time of burning was examined on the Festuca–Stipa grasslands of the Aspen Parklands at the University of Alberta Ranch located 150 km southeast of Edmonton, Alberta. Two defoliation treatments (burning and mowing) were examined on five dates in 1978 (8 April, 27 April, 1 June, 31 July, and 18 October), corresponding to different phenological stages of F. hallii. Burning and mowing reduced the standing crop of F. hallii produced in the first growing season after treatment, but tiller densities increased. Defoliation in early spring (8 April) had little effect on the standing crop; apparently the increase in tiller density compensated for the reduction in tiller length. Inflorescence density also increased following burning or mowing from 8 April to 1 June. Soil temperature (3 cm deep) on previously burned or mown sites was greater than on the control the year after treatment. Festuca hallii tolerates single burns at any time of the year, but early spring fires have the greatest benefits by increased tillering and standing crop. Key words: standing crop, tiller number, leaf length, litter, defoliation, mowing.

scholarly journals Difference in Canopy and Air Temperature as an Indicator of Grassland Water Stress

2013 ◽  
Vol 1 (No. 4) ◽  
pp. 127-138 ◽  
Author(s):  
Duffková Renata
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Moisture Content ◽  
Air Temperature ◽  
Temperature Difference ◽  
Soil Moisture Content ◽  
Growing Season ◽  
Plant Residues ◽  
Dead Plant ◽  
Linear Correlations

In 2003–2005 in conditions of the moderately warm region of the Třeboň Basin (Czech Republic) the difference between canopy temperature (Tc) and air temperature at 2 m (Ta) was tested as an indicator of grass­land water stress. To evaluate water stress ten-minute averages of temperature difference Tc–Ta were chosen recorded on days without rainfall with intensive solar radiation from 11.00 to 14.00 CET. Water stress in the zone of the major portion of root biomass (0–0.2 m) in the peak growing season (minimum presence of dead plant residues) documented by a sudden increase in temperature difference, its value 5–12°C and unfavourable canopy temperatures due to overheating (> 30°C) was indicated after high values of suction pressure approach­ing the wilting point (1300 kPa) were reached. High variability of temperature difference in the conditions of sufficient supply of water to plants was explained by the amount of dead plant residues in canopy, value of va­pour pressure deficit (VPD), actual evapotranspiration rate (ETA) and soil moisture content. At the beginning of the growing season (presence of dead plant residues and voids) we proved moderately strong negative linear correlations of Tc–Ta with VPD and Tc–Ta with ETA rate and moderately strong positive linear correlations of ETA rate with VPD. In the period of intensive growth (the coverage of dead plant residues and voids lower than 10%) moderately strong linear correlations of Tc–Ta with VPD and multiple linear correlations of Tc–Ta with VPD and soil moisture content at a depth of 0.10–0.40 m were demonstrated.

Inoculations of Balsam Fir with Odontiabicolor: Early Establishment and Associated Microorganisms

1975 ◽  
Vol 5 (1) ◽  
pp. 130-138 ◽  
Author(s):  
Denis Lachance
Keyword(s):  
Soil Moisture ◽  
Soil Moisture Content ◽  
Balsam Fir ◽  
Soil Conditions ◽  
Trichoderma Spp ◽  
Inoculation Site ◽  
Opposite Trend ◽  
Apparent Relationship ◽  
Second Year ◽  
A Site

Balsam fir growing on a site having two different soil moisture contents (the drier soil moisture content induced artificially) were inoculated with Odontiabicolor (Alb. & Schw. ex Fr.) Quél. It is shown that the fungus infected roots more readily than trunks, that trunk wounds at 137 cm (4.5 ft) above ground were as susceptible to infection as those at 30 cm (1 ft), and that infection percentages obtained 1 and 2 years after inoculation, although generally higher the second year, were not significantly different. Other fungi, commonly associated with discolored and decayed wood in balsam fir also infected the inoculation wounds, some more frequently root wounds (e.g. Coniophoraputeana, Trichoderma spp.), others trunk wounds (e.g. Retinocyclusabietis, Tympanis spp.). Amylostereumchailletii was isolated significantly more often from roots on wetter than drier soil conditions; Trichoderma spp. showed an opposite trend. O. bicolor apparently followed Graphium spp. at the infection site and was not affected by it as it grew into the wood. An apparent relationship also existed at the inoculation site between O. bicolor and Trichoderma spp.

Effect of Stand Density on Water Use of Mulga (Acacia aneura F.muell.) Woodlands in South-Western Queensland

1976 ◽  
Vol 24 (2) ◽  
pp. 177 ◽  
Author(s):  
AJ Pressland
Keyword(s):  
Soil Moisture ◽  
Water Use ◽  
Stand Density ◽  
Tree Density ◽  
Pan Evaporation ◽  
Permanent Wilting Point ◽  
The Mean ◽  
Acacia Aneura ◽  
Soil Moisture Status ◽  
Wilting Point

The important Australian fodder tree mulga (Acacia aneura F. Muell.) was thinned to densities ranging between 0 and 4000 trees ha-1 near Charleville, Queensland. Water use by the ensuing communities was studied from December 1971 to October 1973. Evapotranspiration over this 22 month period increased with tree density from 814 mm for the totally cleared plots to 852 and 891 mm for those plots supporting 4000 and 640 trees ha-1 respectively. Regression analysis was used to relate soil moisture to time since rain; it was established that the soil had dried to its permanent wilting point within 60 days of rain sufficient to recharge the soil to a depth of 135 cm. The mean apparent maximum evapotranspiration of the mulga communities was 4.7 mm day-1. The ratios of evapotranspiration to pan evaporation (Et/Eo) were influenced by both soil moisture status and tree density. Et/Eo ratios ranged between 0.55 and 0.07 in the summer of 1972, and between 1.05 and 0.05 the following summer. In the winters of 1972 and 1973 Et/Eo ratios ranged between 0.92 and 0.04, and 1.33 and 0.09 respectively. The significance of the results to production and management of mulga lands in south-western Queensland is discussed.

scholarly journals Inter-annual variation of carbon uptake by a plantation oak woodland in south-eastern England

2012 ◽  
Vol 9 (12) ◽  
pp. 5373-5389 ◽  
Author(s):  
M. Wilkinson ◽  
E. L. Eaton ◽  
M. S. J. Broadmeadow ◽  
J. I. L. Morison
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Eddy Covariance ◽  
Carbon Balance ◽  
Annual Variation ◽  
Soil Moisture Content ◽  
Growing Season ◽  
Co2 Uptake ◽  
Growing Season Length ◽  
Net Co2 Uptake

Abstract. The carbon balance of an 80-yr-old deciduous oak plantation in the temperate oceanic climate of the south-east of Great Britain was measured by eddy covariance over 12 yr (1999–2010). The mean annual net ecosystem productivity (NEP) was 486 g C m−2 yr−1 (95% CI of ±73 g C m−2 yr−1), and this was partitioned into a gross primary productivity (GPP) of 2034 ± 145 g C m−2 yr−1, over a 165 (±6) day growing season, and an annual loss of carbon through respiration and decomposition (ecosystem respiration, Reco) of 1548 ± 122 g C m−2 yr−1. Although the maximum variation of NEP between years was large (333 g C m−2 yr−1), the ratio of Reco/GPP remained relatively constant (0.76 ± 0.02 CI). Some anomalies in the annual patterns of the carbon balance could be linked to particular weather events, such as low summer solar radiation and low soil moisture content (values below 30% by volume). The European-wide heat wave and drought of 2003 did not reduce the NEP of this woodland because of good water supply from the surface-water gley soil. The inter-annual variation in estimated intercepted radiation only accounted for ~ 47% of the variation in GPP, although a significant relationship (p < 0.001) was found between peak leaf area index and annual GPP, which modified the efficiency with which incident radiation was used in net CO2 uptake. Whilst the spring start and late autumn end of the net CO2 uptake period varied substantially (range of 24 and 27 days respectively), annual GPP was not related to growing season length. Severe outbreaks of defoliating moth caterpillars, mostly Tortrix viridana L. and Operophtera brumata L., caused considerable damage to the forest canopy in 2009 and 2010, resulting in reduced GPP in these two years. Inter-annual variation in the sensitivity of Reco to temperature was found to be strongly related to summer soil moisture content. The eddy covariance estimates of NEP closely matched mensuration-based estimates, demonstrating that this forest was a substantial sink of carbon over the 12-yr measurement period.

scholarly journals The effect of rainfall and extensive use of grasslands on water regime

2011 ◽  
Vol 48 (No. 3) ◽  
pp. 89-95
Author(s):  
R. Duffková
Keyword(s):  
Land Use ◽  
Soil Moisture ◽  
Moisture Content ◽  
Water Regime ◽  
Soil Moisture Content ◽  
Growing Season ◽  
Water Runoff ◽  
Botanical Composition ◽  
Significant Difference ◽  
Determinant Factor

&nbsp;Water regimes of extensively used grasslands (one cut per year, two cuts per year, no cut, mulching) were determined and compared by drainage lysimeters in 1998&ndash;2000. Although the botanical composition and yields of experimental swards were different, there was no statistically significant difference in their water regime (only the soil moisture content of no-cut variant was significantly higher than in other variants). A&nbsp;determinant factor for the water regime of grasslands (GR) is the sum of rainfall over the growing season while the GR water regime is influenced by land use immediately after the cut. Water runoff from the soil profile 0.0&ndash;0.60 m (water supply to the groundwater level) was found to be negligible in the growing season, a&nbsp;substantial groundwater recharge occurs in an off-season period and/or at the beginning of growing season. Mulching was not proved to reduce evaporation. The best type of management providing for the economical water regime appears to be a&nbsp;one-cut variant. Relationships between botanical composition and GR water regime are also described.

REGRESSIONS FOR ESTIMATING STRAW YIELDS AND N AND P CONTENTS OF SPRING WHEAT AND N MINERALIZATION IN A BROWN LOAM SOIL

1988 ◽  
Vol 68 (2) ◽  
pp. 337-344 ◽  
Author(s):  
C. A. CAMPBELL ◽  
R. P. ZENTNER ◽  
F. SELLES
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Spring Wheat ◽  
N Mineralization ◽  
Soil Moisture Content ◽  
N Uptake ◽  
Growing Season ◽  
Net N Mineralization ◽  
Loam Soil ◽  
Growing Season Precipitation

Data from an 18-yr crop rotation study carried out on a Brown loam soil at Swift Current, Saskatchewan, were used to estimate equations that relate spring wheat straw yields, and N and P content of grain and straw to moisture use (MU). Moisture use was defined as soil moisture content in 0- to 120-cm depth at seeding, less soil moisture content at harvest, plus growing season precipitation. Grain yields were also related to straw yields and to N content of the straw. Potential net N mineralization (Nmin) in summerfallow (periods during the growing season with negative Nmin omitted) was related (r = 0.74**) to precipitation received during the spring to fall period. An attempt to relate apparent net Nmin (determined by N balance) in cropped systems to growing season precipitation or to MU was not successful. Highly significant linear regressions were obtained for straw yields, grain N and P contents vs. MU, and for grain yield vs. straw yield (r = 0.66** – 0.83**), but the other relationships were less reliable (r = 0.41** – 0.55**) though still significant. We discussed how these relationships might be used to estimate fertilizer N requirements, for examining N immobilization-mineralization, and for estimating residue sufficiency for erosion control on summerfallowed land. Key words: Straw:grain ratio, N uptake, P uptake, crop residues, N mineralization

scholarly journals WATER TABLE BEHAVIOR AND SOIL MOISTURE CONTENT DURING THE WINTER

1970 ◽  
Vol 50 (3) ◽  
pp. 361-366 ◽  
Author(s):  
J. C. van SCHAIK ◽  
E. RAPP
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Water Table ◽  
Soil Moisture Content ◽  
Growing Season ◽  
Grass Cover ◽  
Irrigation Project ◽  
Southern Alberta

Water table recession in an irrigation project in southern Alberta was compared with moisture translocation in covered lysimeters during two winters. Upward translocation to the surface 60 cm during one winter amounted to 1 to 2 cm of water in dry soils having a grass cover, and 2 to 2.3 cm in moist soils with no vegetation. Observations between growing season and freeze-up indicated that a considerable amount of water may drain downward. The upper 30 cm of soil generally is not influenced by upward translocation if the soil is dry before freeze-up.

scholarly journals Physiological responses to drought of Cnidoscolus quercifolius Pohl in semi-arid conditions

2019 ◽  
Vol 6 (1) ◽  
pp. 493 ◽  
Author(s):  
Fabio Rodrigues Ramos ◽  
Antonio Lucineudo Oliveira Freire
Keyword(s):  
Soil Moisture ◽  
Stomatal Conductance ◽  
Moisture Content ◽  
Water Content ◽  
Water Use ◽  
Transpiration Rate ◽  
Relative Water Content ◽  
Soil Moisture Content ◽  
Relative Water ◽  
Use Efficiency

This study aimed to evaluate the physiological behavior of faveleira (Cnidoscolus quercifolius Pohl) plants grown in the field, in Caatinga, during wet and dry seasons. Adult plants were selected for evaluation in March and April (wet season) and May and June (dry season), during 2016. We evaluated the soil water content, water potential (Ψw), osmotic potential (Ψπ), relative water content (RWC), stomatal conductance (gs), transpiration rate (E), photosynthetic rate (A), intercellular CO2 concentration (Ci), instantaneous water use efficiency (A/E) and carboxylation efficiency (A/Ci). The reduction in water availability in the soil promoted a marked decrease in soil water potential, which was more affected than the relative water content. The opening of the stomata was affected by the decrease in soil moisture content, reducing the stomatal conductance, transpiration rate, photosynthesis rate, instantaneous water use efficiency and carboxylation efficiency. The photosynthesis was more affected than transpiration by the reduction in soil moisture content.

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