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

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.

2008 ◽  
Vol 5 (2) ◽  
pp. 1237-1261 ◽  
Author(s):  
A. P. Schrier-Uijl ◽  
E. M. Veenendaal ◽  
P. A. Leffelaar ◽  
J. C. van Huissteden ◽  
F. Berendse

Abstract. Our research investigates the spatial and temporal variability of methane (CH4) emissions in two drained eutrophic peat areas (one intensively managed and the other less intensively managed) and the correlation between CH4 emissions and soil temperature, air temperature, soil moisture content and water table. We stratified the landscape into landscape elements that represent different conditions in terms of topography and therefore differ in moisture conditions. There was great spatial variability in the fluxes in both areas; the ditches and ditch edges (together 27% of the landscape) were methane hotspots whereas the dry fields had the smallest fluxes. In the intensively managed site the fluxes were significantly higher by comparison with the less intensively managed site. In all the landscape element elements the best explanatory variable for CH4 emission was temperature. Neither soil moisture content nor water table correlated significantly with CH4 emissions, except in April, where soil moisture was the best explanatory variable.


10.29007/5swr ◽  
2018 ◽  
Author(s):  
Paolina Bongioannini Cerlini ◽  
Silvia Meniconi ◽  
Bruno Brunone

With the aim of refining a reliable tool for groundwater management, the ERA-Interim and ERA5 global atmospheric datasets provided by the European Centre for Medium- Range Weather Forecasts (ECMWF) are examined. Attention is focused on the analysis of the behavior of the soil moisture content. The performance of ERA-Interim and ERA5 is evaluated by considering the water table measurements at three sites in the Umbria region as well as the dynamics of water flow towards the groundwater.


2013 ◽  
Vol 1 (No. 4) ◽  
pp. 127-138 ◽  
Author(s):  
Duffková Renata

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.


1982 ◽  
Vol 62 (2) ◽  
pp. 407-413 ◽  
Author(s):  
T. G. SOMMERFELDT ◽  
C. CHANG ◽  
J. M. CAREFOOT

A column study was conducted to determine the effects of soil texture, initial soil moisture content and timing of leaching on N removal from two irrigated soils of southern Alberta. Pelleted NH4NO3 fertilizer (0.639 g N per column = 336 kg∙ha−1) was applied to Lethbridge loam (Leth L) and Cavendish fine sandy loam (CV FSL) at three initial levels of soil moisture: air dry (AD), 0.5 field capacity (0.5 FC), and wet (W, 25 cm suction). Leaching began immediately after the fertilizer application or was delayed 1 wk. Water was applied in 1400-mL (7.6 cm depth) increments every 2nd day for a total of 33 600 mL (175 cm depth). The leachate was collected, measured, and analyzed for NH4-N and NO3-N. The soil was analyzed for N content before and after leaching. More N was leached from CV FSL (0.600 g) than from Leth L (0.521 g). Responses to initial soil moisture were similar for both soils; the NO3-N concentration peak followed the advancing wetting front more closely in the AD than in the W systems and leaching losses were greatest from the 0.5 FC treatment. Delayed leaching did not significantly affect the amount of N leached. N losses, other than from leaching, were greatest in the W and AD treatments, in the AD treatment these losses were attributed to volatilization and, in the W soils, to denitrification.


2012 ◽  
Vol 9 (12) ◽  
pp. 5373-5389 ◽  
Author(s):  
M. Wilkinson ◽  
E. L. Eaton ◽  
M. S. J. Broadmeadow ◽  
J. I. L. Morison

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.


2011 ◽  
Vol 48 (No. 3) ◽  
pp. 89-95
Author(s):  
R. Duffková

&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.


1988 ◽  
Vol 68 (2) ◽  
pp. 337-344 ◽  
Author(s):  
C. A. CAMPBELL ◽  
R. P. ZENTNER ◽  
F. SELLES

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


1970 ◽  
Vol 50 (1) ◽  
pp. 43-45
Author(s):  
D. N. GRAVELAND

A saline sodic soil with a fluctuating water table was sampled once a week during the growing season and once every ten days until January to study the migration of soluble salts. The area, which was in pasture, was irrigated three times during the summer. The changes in soluble salt concentration were compared with the precipitation records, soil moisture content and water table levels. During the growing season, the soluble salt content varied over 100% and had an inverse relationship with moisture content.


Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3351
Author(s):  
Tianxing Zhao ◽  
Yan Zhu ◽  
Jingwei Wu ◽  
Ming Ye ◽  
Wei Mao ◽  
...  

Water storage in unsaturated and saturated zones during the crop non-growing season is one of the important supplementary water resources to meet crop water requirements in arid areas with shallow water table depth. It is necessary to analyze utilization of the soil-ground water storage during the crop growing season and its attribution to irrigation during the non-growing season. To facilitate the analysis, a new method based on measurements of soil moisture content and water table depth is developed. The measurements used in this study include (1) 15-year data of soil moisture content within a depth of 1 m from the land surface and water table depth measured in Jiefangzha, including its four subareas and (2) 4-year data of the same kind in Yonglian, located in arid northern China. The soil-ground water storage utilization is calculated as the difference of water storage between the beginning and end of the crop growing season in the whole computational soil profile. The results of average soil-ground water storage utilization in Jiefangzha and its four subareas and Yonglian are 121 mm, 126 mm, 113 mm, 124 mm, 185 mm and 117 mm, and the corresponding average utilization efficiencies in the non-growing season are 32.2%, 32.5%, 31.5%, 31.6%, 57.3% and 47.6%, respectively. Further, the water table fluctuation method was used to estimate the variation in water storage. The coefficients of soil-ground water storage utilization, soil-ground water storage utilization below 1 m soil depth and ground water utilization are defined, and their average values are 0.271, 0.111 and 0.026 in Jiefangzha, respectively. Then, the contribution of soil-ground water storage utilization to actual evapotranspiration is evaluated, which are over 23.5% in Jiefangzha and Yonglian. These results indicate that the soil-ground water storage plays an important role in the ecological environment in arid areas with shallow water table depth.


1974 ◽  
Vol 54 (1) ◽  
pp. 141-147 ◽  
Author(s):  
I. V. HALL ◽  
R. A. MURRAY ◽  
L. P. JACKSON

Spiraea latifolia (Ait.) Borkh., broad-leaved meadowsweet (Rosaceae), is a weed of pastures, lowbush blueberry (Vaccinium angustifolium Ait. and V. myrtilloides Mich.) fields and cranberry (V. macrocarpon Ait.) bogs of Eastern Canada, especially where soil moisture content is high during the growing season. Where S. latifolia occurs, other vegetation is lacking or depressed. Much time is lost in harvesting lowbush blueberries due to jamming of the S. latifolia stems among the tines of the rake or in cranberries due to mechanical damage to the harvesters. In Canada, S. latifolia occurs in Newfoundland, Prince Edward Island, Nova Scotia, New Brunswick, Quebec, Ontario, and Manitoba.


Sign in / Sign up

Export Citation Format

Share Document