WATER UPTAKE BY ORCHARDGRASS AND EVAPORATION FROM BARE SOIL IN THE PRESENCE OF SHALLOW WATER TABLES

Lysimeter studies in 1967 showed that evapotranspiration by orchardgrass from June 16 to September 15 was 38.8, 37.2, and 34.9 cm with water tables at depths of 91, 122, and 152 cm. This amounted to about 60% of the potential evapotranspiration and was nearly all due to transpiration. Evaporation from a bare soil in 1967 was not high enough to influence salt concentration of the surface soil. Most salinization of the cropped soil is expected to occur outside the growing season, if the water tables do not fluctuate.

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THREE YEARS OF EVAPOTRANSPIRATION AT TORONTO

Canadian Journal of Research ◽

10.1139/cjr50c-028 ◽

1950 ◽

Vol 28c (5) ◽

pp. 482-492 ◽

Cited By ~ 6

Author(s):

Marie Sanderson

Keyword(s):

Water Loss ◽

Surface Soil ◽

Potential Evapotranspiration ◽

Bare Soil ◽

Potential Evaporation ◽

Moist Soil ◽

Growing Seasons ◽

Dry Soil

An experiment to measure the daily potential evapotranspiration from vegetation-covered soil surfaces was conducted in Toronto during the 1947, 1948, and 1949 growing seasons. The potential evaporation from moist bare soil was also measured and compared with the evaporation from dry soil. Results indicate that the Thornthwaite formula for computing potential water loss is valid at this latitude for both vegetation-covered and moist soil. When drying of the surface soil occurred, the water loss was diminished.

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IS DEEP SOWING BENEFICIAL FOR DRY SEASON CROPPING WITHOUT IRRIGATION ON SANDY SOIL WITH SHALLOW WATER TABLE?

Experimental Agriculture ◽

10.1017/s0014479713000161 ◽

2013 ◽

Vol 49 (3) ◽

pp. 366-381

Author(s):

B. BUAKUM ◽

V. LIMPINUNTANA ◽

N. VORASOOT ◽

K. PANNANGPETCH ◽

R. W. BELL

Keyword(s):

Shallow Water ◽

Water Content ◽

Soil Water ◽

Water Table ◽

Growing Season ◽

Dry Season ◽

Shallow Water Table ◽

Water Tables ◽

Permanent Wilting Point ◽

Wilting Point

SUMMARYDeep sowing (15 cm) on sands in the dry season is a practice used in post-rice sowing of legumes without irrigation, designed to increase moisture access for germination, growth and crops yield. However, with such deep sowing there can be a penalty for emergence and growth if there is abundant water stored in the upper soil profile during the growing season. Hence, there is a need to define the soil water regimes under which deep sowing is advantageous for different legumes. To investigate the adaptation of legume crop species to deep sowing, we studied their emergence, growth and yield on three deep soils (3–16% clay) with shallow water tables during two years in northeast Thailand. At site 1 and 2, peanut, cowpea, mungbean and soybean were sown shallow (~5 cm) or deep (~15 cm). At site 3, only cowpea and peanut were shallow or deep sown. Shallow water tables maintained soil water content (0–15 cm) above permanent wilting point throughout the growing season. Deep sowing of all legumes delayed emergence by 3–7 days at all locations. Shoot dry weight of legumes after deep sowing was mostly similar or lower than weight after shallow sowing. Yield and harvest index of legumes did not differ meaningfully among sowing depths. Therefore, deep sowing was not beneficial for dry season cropping without irrigation when there was a shallow water table and sufficient water for crop growth throughout soil profiles in the growing season. Taken together with previous studies, we conclude that shallow rather than deep sowing of legumes was preferred when the soil water content at 0–15-cm depth remained higher than permanent wilting point throughout the growing season due to shallow water table.

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Climate Change Patterns of Wild Blueberry Fields in Downeast, Maine over the Past 40 Years

Water ◽

10.3390/w13050594 ◽

2021 ◽

Vol 13 (5) ◽

pp. 594

Author(s):

Rafa Tasnim ◽

Francis Drummond ◽

Yong-Jiang Zhang

Keyword(s):

Climate Change ◽

Vegetation Index ◽

Potential Evapotranspiration ◽

Growing Season ◽

Spatial Average ◽

Climate Variables ◽

Threshold Values ◽

The Past ◽

Wild Blueberry ◽

Crop Health

Maine, USA is the largest producer of wild blueberries (Vaccinium angustifolium Aiton), an important native North American fruit crop. Blueberry fields are mainly distributed in coastal glacial outwash plains which might not experience the same climate change patterns as the whole region. It is important to analyze the climate change patterns of wild blueberry fields and determine how they affect crop health so fields can be managed more efficiently under climate change. Trends in the maximum (Tmax), minimum (Tmin) and average (Tavg) temperatures, total precipitation (Ptotal), and potential evapotranspiration (PET) were evaluated for 26 wild blueberry fields in Downeast Maine during the growing season (May–September) over the past 40 years. The effects of these climate variables on the Maximum Enhanced Vegetation Index (EVImax) were evaluated using Remote Sensing products and Geographic Information System (GIS) tools. We found differences in the increase in growing season Tmax, Tmin, Tavg, and Ptotal between those fields and the overall spatial average for the region (state of Maine), as well as among the blueberry fields. The maximum, minimum, and average temperatures of the studied 26 wild blueberry fields in Downeast, Maine showed higher rates of increase than those of the entire region during the last 40 years. Fields closer to the coast showed higher rates of warming compared with the fields more distant from the coast. Consequently, PET has been also increasing in wild blueberry fields, with those at higher elevations showing lower increasing rates. Optimum climatic conditions (threshold values) during the growing season were explored based on observed significant quadratic relationships between the climate variables (Tmax and Ptotal), PET, and EVImax for those fields. An optimum Tmax and PET for EVImax at 22.4 °C and 145 mm/month suggest potential negative effects of further warming and increasing PET on crop health and productivity. These climate change patterns and associated physiological relationships, as well as threshold values, could provide important information for the planning and development of optimal management techniques for wild blueberry fields experiencing climate change.

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COMPUTER ASSISTED MAPPING OF SOIL EROSION POTENTIAL

Canadian Journal of Soil Science ◽

10.4141/cjss85-045 ◽

1985 ◽

Vol 65 (3) ◽

pp. 411-418 ◽

Cited By ~ 3

Author(s):

T. VOLD ◽

M. W. SONDHEIM ◽

N. K. NAGPAL

Keyword(s):

Soil Erosion ◽

Soil Loss ◽

Surface Soil ◽

Mineral Soil ◽

Weighted Average ◽

Bare Soil ◽

Computer Assisted ◽

Additional Information ◽

Potential Map ◽

Fraser Valley

Soil erosion potential maps and summary statistics can be produced from existing information with relative ease with the aid of computers. Soil maps are digitized and survey information is stored as attributes for each soil. Algorithms are then prepared which evaluate the appropriate data base attributes (e.g. texture, slope) for each interpretation. Forty surface soil erosion potential maps were produced for the Lower Fraser Valley which identify the most erosion-prone areas and indicate average potential soil losses to be expected under assumed conditions. The algorithm developed follows the universal soil loss equation. Differences across the landscape in the R, K, and S factors are taken into account whereas the L factor is considered as a constant equal to 1.0. Worst conditions of bare soil (no crop cover, i.e. C = 1.0) and no erosion control practices (i.e. P = 1.0) are assumed. The five surface soil erosion potential classes are determined by a weighted average annual soil loss value based both on the upper 20 cm of mineral soil and on the proportion of the various soils in the polygon. A unique polygon number shown on the erosion potential map provides a link to computer tables which give additional information for each individual soil within that polygon. Key words: Erosion, computer mapping, USLE

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Alfalfa water use pinpointed in saline, shallow water tables of Imperial Valley

California Agriculture ◽

10.3733/ca.v055n04p38 ◽

2001 ◽

Vol 55 (4) ◽

pp. 38-43 ◽

Cited By ~ 7

Author(s):

Khaled M. Bali ◽

Mark E. Grismer ◽

Richard L. Snyder

Keyword(s):

Shallow Water ◽

Water Use ◽

Imperial Valley ◽

Water Tables

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SALT ACCUMULATION IN A GLACIAL TILL SOIL IN THE PRESENCE OF SALINE GROUNDWATER AT SHALLOW DEPTHS

Canadian Journal of Soil Science ◽

10.4141/cjss63-016 ◽

1963 ◽

Vol 43 (1) ◽

pp. 135-140 ◽

Cited By ~ 1

Author(s):

J. C. van Schaik ◽

R. A. Milne

Keyword(s):

Shallow Water ◽

Glacial Till ◽

Salt Accumulation ◽

Saline Groundwater ◽

Low Salinity ◽

Saturation Extract ◽

Tile Drains ◽

Southern Alberta ◽

Water Tables ◽

Fallow Soil

Considerable salt accumulation occurred in a grass-covered soil in southern Alberta where the saline groundwater was maintained at a depth of 3 feet. The SAR values of the saturation extract increased significantly under grass, and indications are that this increase was mainly due to precipitation of calcium. A fallow soil did not show a significant salt accumulation above the water table.It is suggested that a leaching program is necessary to maintain low salinity where shallow water tables are present and shallow tile drains are used.

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Soil Hydraulic Parameters and Surface Soil Moisture of a Tilled Bare Soil Plot Inversely Derived from L-Band Brightness Temperatures

Vadose Zone Journal ◽

10.2136/vzj2013.04.0075 ◽

2014 ◽

Vol 13 (1) ◽

pp. vzj2013.04.0075 ◽

Cited By ~ 10

Author(s):

M. Dimitrov ◽

J. Vanderborght ◽

K. G. Kostov ◽

K. Z. Jadoon ◽

L. Weihermüller ◽

...

Keyword(s):

Soil Moisture ◽

Surface Soil ◽

Bare Soil ◽

Hydraulic Parameters ◽

Surface Soil Moisture ◽

Brightness Temperatures ◽

Soil Hydraulic Parameters ◽

L Band ◽

Soil Hydraulic

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Soil Moisture Analysis by Means of Multispectral Images According to Land Use and Spatial Resolution on Andosols in the Colombian Andes

Applied Sciences ◽

10.3390/app10165540 ◽

2020 ◽

Vol 10 (16) ◽

pp. 5540 ◽

Cited By ~ 1

Author(s):

Maria Casamitjana ◽

Maria C. Torres-Madroñero ◽

Jaime Bernal-Riobo ◽

Diego Varga

Keyword(s):

Soil Moisture ◽

Vegetation Index ◽

Surface Soil ◽

Vegetation Indices ◽

Bare Soil ◽

Multispectral Images ◽

Surface Soil Moisture ◽

Mountain Environments ◽

Tropical Mountain ◽

Moisture Analysis

Surface soil moisture is an important hydrological parameter in agricultural areas. Periodic measurements in tropical mountain environments are poorly representative of larger areas, while satellite resolution is too coarse to be effective in these topographically varied landscapes, making spatial resolution an important parameter to consider. The Las Palmas catchment area near Medellin in Colombia is a vital water reservoir that stores considerable amounts of water in its andosol. In this tropical Andean setting, we use an unmanned aerial vehicle (UAV) with multispectral (visible, near infrared) sensors to determine the correlation of three agricultural land uses (potatoes, bare soil, and pasture) with surface soil moisture. Four vegetation indices (the perpendicular drought index, PDI; the normalized difference vegetation index, NDVI; the normalized difference water index, NDWI, and the soil-adjusted vegetation index, SAVI) were applied to UAV imagery and a 3 m resolution to estimate surface soil moisture through calibration with in situ field measurements. The results showed that on bare soil, the indices that best fit the soil moisture results are NDVI, NDWI and PDI on a detailed scale, whereas on potatoes crops, the NDWI is the index that correlates significantly with soil moisture, irrespective of the scale. Multispectral images and vegetation indices provide good soil moisture understanding in tropical mountain environments, with 3 m remote sensing images which are shown to be a good alternative to soil moisture analysis on pastures using the NDVI and UAV images for bare soil and potatoes.

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