An empirical model for drainage from soil under rain fed conditions

Soil Research ◽  
1977 ◽  
Vol 15 (3) ◽  
pp. 205 ◽  
Author(s):  
AR Aston ◽  
FX Dunin
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Empirical Model ◽  
Sandy Loam ◽  
Empirical Relationship ◽  
Field Conditions ◽  
Natural Field ◽  
Moisture Contents ◽  
Weighing Lysimeter

An empirical relationship was derived for drainage from a podzolic sandy loam using a weighing lysimeter at Krawarree, N.S.W. The form of the equation was similar to those used to describe drainage following irrigation. The agreement between computed and measured soil moisture contents over a period of five years was good, and indicated the usefulness of such an approach to characterize drainage of soil water under natural field conditions.

Soil water drying and recharge rates as affected by tillage under continuous barley and barley-canola cropping systems in northwestern Canada

2001 ◽  
Vol 81 (1) ◽  
pp. 45-52 ◽  
Author(s):  
R H Azooz ◽  
M A Arshad
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Sandy Loam ◽  
Time Domain Reflectometry ◽  
Sandy Loam Soil ◽  
Soil Conditions ◽  
Silt Loam ◽  
Silt Loam Soil ◽  
Loam Soil ◽  
The Impact

In areas of the northwestern Canadian Prairies, barley and canola are grown in a short growing season with high rainfall variability. Excessively dry soil in conventional tillage (CT) in dry periods and excessively wet soil in no-tillage (NT) in wet periods could cause a significant decrease in crop production by influencing the availability of soil water. The effects of CT, NT and NT with a 7.5-cm residue-free strip on the planting rows (NTR) on soil water drying (–dW/dt) and recharge (dW/dt) rates were studied in 1992 and 1993 during wet and dry periods to evaluate the impact of NTR, NT and CT systems on soil moisture condition. The soils, Donnelly silt loam and Donnelly sandy loam (both Gray Luvisol) were selected and soil water content by depth was measured by time domain reflectometry. Water retained at 6 matric potentials from –5 to –160 kPa were observed. In the field study, –dW/dt was significantly greater in CT than in NT in the silt loam for the 0- to 30-cm layer during the first 34 d after planting in 1992. The 0- to 30-cm soil layer in CT and NTR dried faster than in NT during a period immediately following heavy rainfall in the silt loam in 1993. The drying coefficient (–Kd ) was significantly greater in CT and NTR than in NT in the silt loam soil in 1993 and in the sandy loam soil in 1992 in the top 30-cm depth. The recharge coefficient (Kr) was significantly greater in NT and NTR than in CT for the silt loam soil. The NTR system increased the –dW/dt by 1.2 × 10-2 to 12.1 × 10-2 cm d-1 in 1992 and 1993 in the silt loam soil and by 10.2 × 10-2 cm d-1 in 1993 in the sandy loam soil as compared with NT. The dW/dt was 8.1 × 10-2 cm d-1 greater in NTR in 1992 and 1993 in the silt loam soil and was 1.9 × 10-2 greater in NTR in 1992 than in CT in the sandy loam soil. The laboratory study indicated that NT soils retained more water than the CT soils. The NTR practice maintained better soil moisture conditions for crop growth than CT in dry periods than NT in wet periods. Compared with NT, the NTR avoided prolonged near-saturated soil conditions with increased soil drying rate under extremely wet soil. Key words: Water drying, water recharge, water depletion, wet and drying periods, hydraulic properties, soil capacity to retain water

scholarly journals Effects of Variable Angular Velocities and Soil Moisture Contents on Undrained Shear Strength in a Sandy Loam Soil (Eutric Leptosol)

2016 ◽  
Vol 11 (2) ◽  
pp. 49-60
Author(s):  
David Lomeling ◽  
Juma L.L. Yieb ◽  
Modi A. Lodiong ◽  
Mandlena C. Kenyi ◽  
Moti S. Kenyi ◽  
...  
Keyword(s):  
Shear Strength ◽  
Soil Moisture ◽  
Sandy Loam ◽  
Undrained Shear Strength ◽  
Sandy Loam Soil ◽  
Moisture Contents ◽  
Angular Velocities ◽  
Loam Soil ◽  
Undrained Shear

Monitoring Shallow Soil Water Content Under Natural Field Conditions Using the Early-Time GPR Signal Technique

2013 ◽  
Vol 12 (4) ◽  
pp. vzj2012.0202 ◽  
Author(s):  
C. Ferrara ◽  
P.M. Barone ◽  
C. M. Steelman ◽  
E. Pettinelli ◽  
A.L. Endres
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Early Time ◽  
Field Conditions ◽  
Natural Field ◽  
Shallow Soil

EFFECTS OF SOIL WATER MOVEMENT ON ACTUAL EVAPOTRANSPIRATION ESTIMATED FROM THE SOIL MOISTURE BUDGET

1970 ◽  
Vol 50 (3) ◽  
pp. 409-417 ◽  
Author(s):  
WAYNE R. ROUSE
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Water Movement ◽  
Potential Evapotranspiration ◽  
Sandy Loam ◽  
Spatial Variations ◽  
Actual Evapotranspiration ◽  
Moisture Budget ◽  
Loam Soil ◽  
Soil Moisture Budget

Actual evapotranspiration was estimated from the soil moisture budget for a grass-covered sandy loam soil at Simcoe, Ontario. Soil moisture was measured at 25 sites distributed over a 6-meter-square grid. The coefficient of variation for actual evapotranspiration estimated at all sites averaged 13% and rose as high as 19%. Average actual evapotranspiration exceeded both the Penman and Thornthwaite estimates of potential evapotranspiration for three of the six measuring intervals, due to deep seepage losses. The application of corrections for the vertical water movement, determined from experimentally derived matric suction and hydraulic conductivity data, gave a substantial deep seepage loss for some periods and a capillary uptake of soil water for others. Vertical losses and gains created errors of up to + 28 and − 29%, respectively, in the standard estimates of actual evapotranspiration. The large spatial variations in evapotranspiration estimates resulted from variations in volumetric soil moisture between sample points, apparently creating differences in the magnitude and direction of vertical water movement across the terminal depth. The horizontal flux of water between measuring points was relatively unimportant in accounting for the spatial variations.

Soil water content sensors from laboratory calibration to field monitoring: discrepancies and uncertainties

2021 ◽  
Author(s):  
Angela Gabriela Morales Santos ◽  
Reinhard Nolz
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Soil Water ◽  
Root Zone ◽  
Sandy Loam ◽  
Irrigation Scheduling ◽  
Water Monitoring ◽  
Rooting Depth ◽  
Water Fraction ◽  
Laboratory Calibration

<p>Monitoring soil water status is one key option to optimise water use in agriculture. Soil moisture sensors are widely used for investigating available soil water to optimally adapt irrigation scheduling to crop water requirements. Although reliable measurements are subject to proper soil-specific calibration of sensors, meaningful calibration functions are not always available. Another question is the plausibility of soil water monitoring under field conditions. The objective of this study was to calibrate four multi-sensor capacitance probes in the laboratory and  to evaluate the calibrated water content readings under natural conditions in an irrigated field by means of a modelling approach.</p><p>The multi-sensor capacitance probes (SM1 by ADCON Telemetry) were of 90 cm length and contained nine sensors (S1 to S9) at 10 cm spacing. The digital output values were given in scaled frequency units (SFU). The laboratory calibration was carried out on sandy loam and sand. Measurements were undertaken by placing the probes inside a PVC tube backfilled with soil at different water contents. Soil samples were collected using metallic cylinders of 250 cm<sup>3</sup>, from which volumetric water content (θ) was determined gravimetrically. The sensor readings in soil were normalised by using sensor readings in air and water as lower and upper limit, respectively. The pairs of measured θ and normalised SFU were related to each other by curve fitting. For each soil type, eight sensor-specific calibration functions were developed that allowed the calculation of θ in cm<sup>3</sup> cm<sup>−</sup><sup>3</sup> from SM1 readings.</p><p>After calibration, the SM1 probes were installed in a field in Obersiebenbrunn, Lower Austria, where sandy loam is the main soil. Three of the probes monitored irrigated plots and the fourth a rainfed plot. To obtain reference values, one HydraProbe soil moisture sensor (Stevens Water Monitoring Systems) was installed in 20 cm depth, near each SM1. The average daily θ-values from the S2 (20 cm depth) contained in each SM1 probe were compared to the water fraction collected with the corresponding HydraProbe. Moreover, the SM1 θ-values were used to determine the daily soil water depletion in the root zone (Dr) for a rooting depth of 1 m. The obtained Dr datasets were compared to Dr simulated using CROPWAT 8.0 by FAO.</p><p>The field results showed that the SM1 probes were able to reproduce the HydraProbe dynamics of wetting and drying periods during the crop season. Nevertheless, a considerable difference was noted between the sensor measurements. The SM1 overestimated θ in the irrigated plots, whereas it underestimated θ in the rainfed plot. The discrepancies can be attributed mainly to the different physical mechanisms behind the sensors and to the unfeasible reproduction of field bulk density and soil structure in the laboratory. Furthermore, the operational frequency and permittivity response of the SM1 probes should be revised for future versions. The simulation results showed that the observed Dr values were more consistent with CROPWAT Dr results at the end of the simulation period, suggesting that the SM1 required several weeks to consolidate and give representative θ-values for the soil profile.</p>

INFLUENCE OF SOIL MOISTURE ON COLD TOLERANCE OF ALFALFA

1980 ◽  
Vol 60 (1) ◽  
pp. 139-147 ◽  
Author(s):  
ROGER PAQUIN ◽  
GUY R. MEHUYS
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Sandy Loam ◽  
Freezing Process ◽  
Plant Survival ◽  
Hardening Process ◽  
Ap Horizon ◽  
Soil Water Holding Capacity ◽  
Water Treatments ◽  
Water Holding

Drought stress applied to alfalfa seedlings (Medicago media Pers.) grown at 20–22 °C by reducing soil moisture from 100 to 30% of soil water holding capacity prior to freezing increased their LT50 by 4–7 °C. The tests were performed in 12-cm pots containing either a greenhouse sandy loam potting mixture or material sampled in the Ap horizon of several soils of varying texture. Similar increases were obtained when identical soil water treatments were applied to plants hardened for 2 or 4 wk at 1 °C. Both stresses, drought and low temperature, have additive influences on plant survival following freezing. Low soil moisture increased both the level of cold hardening achieved and plant survival to freezing, but it had a larger effect on the freezing process than on the hardening process. Freezing tests carried out with insulated pots, in order to simulate field conditions where frost comes from above, did not affect the survival of alfalfa in spite of a delay in the cooling of the soil. Differences in cooling rates during freezing could not be correlated with the higher mortality observed with moist soils.

The root growth of irrigated perennial pastures and its effect on soil structure.

1953 ◽  
Vol 4 (3) ◽  
pp. 283 ◽  
Author(s):  
KP Barley
Keyword(s):  
Soil Moisture ◽  
Root Growth ◽  
Soil Structure ◽  
Sandy Loam ◽  
Perennial Grass ◽  
Infiltration Rate ◽  
Matter Content ◽  
Infiltration Rates ◽  
Moisture Contents ◽  
Organic Particles

A separate of coherent organic particles obtained from soil suspensions by flotation and filtration is termed macroorganic matter. Three-year-old irrigated perennial pastures were found to have added 10 tons per acre of oven-dry macroorganic matter to a sandy loam at Deniliquin. Over half of this material hail been added to the top three inches of the soil. For any one pasture, as the macroorganic matter content of the top three inches of soil increased, infiltration rate decreased. When comparison was made at common macroorganic matter and soil moisture contents, soils under co-dominant white clover-perennial grass pastures were found to have higher infiltration rates than soils under lucerne-dominant pastures. The variability of the quantities measured is described.

scholarly journals YIELD AND QUALITY OF ONION VARIETIES TO THREE SOIL MOISTURE REGIMES IN LYSIMETERS AND FIELD CONDITIONS IN NIGER, WEST AFRICA.

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 587a-587
Author(s):  
CHIT RK PRASHAR ◽  
GOVIND C. SHARMA
Keyword(s):  
Soil Moisture ◽  
Sandy Loam ◽  
Soil Depth ◽  
Field Conditions ◽  
Medium Size ◽  
The Past ◽  
Yield And Quality ◽  
Moisture Regimes ◽  
The Mean

Yield and quality responses to Galmi Violet, Galmi White and Sumrana Violet were studied during 1990-91 and 1991-92 in Maradi region in Niger. Three regimes comprised of irrigating when the soil moisture depletion in 20 cm of soil depth was 40%, 60% and 80%. Investigations were carried out both under field conditions and in the lysimeters. The soil was sandy loam to loam. The lysimeters were 2m×2m×1m drainage type and well set over the past twenty years. The crop was raised during the dry season from October to March with no rainfall. Despite the low temperatures the radiation levels were high. Onion yield was higher under low irrigation regime. The mean yield was 32.5 tons/ha. However, the bulk density was higher under higher moisture regimes. The keeping quality over eight month period was not affected by soil moisture regimes. The bulbs of Sumrana Violet were of medium size whereas the bulbs of Galmi Violet and White were larger size. From a market acceptability standpoint violet onions were preferred over the white ones.

scholarly journals Irrigation Scheduling Based on Wireless Sensors Output and Soil-Water Characteristic Curve in Two Soils

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1336 ◽  
Author(s):  
J.D. Jabro ◽  
W.B. Stevens ◽  
W.M. Iversen ◽  
B.L. Allen ◽  
U.M. Sainju
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Water ◽  
Root Zone ◽  
Sandy Loam ◽  
Characteristic Curve ◽  
Field Capacity ◽  
Irrigation Scheduling ◽  
Clay Loam ◽  
Soil Water Characteristic Curve

Data-driven irrigation planning can optimize crop yield and reduce adverse impacts on surface and ground water quality. We evaluated an irrigation scheduling strategy based on soil matric potentials recorded by wireless Watermark (WM) sensors installed in sandy loam and clay loam soils and soil-water characteristic curve data. Five wireless WM nodes (IRROmesh) were installed at each location, where each node consisted of three WM sensors that were installed at 15, 30, and 60 cm depths in the crop rows. Soil moisture contents, at field capacity and permanent wilting points, were determined from soil-water characteristic curves and were approximately 23% and 11% for a sandy loam, and 35% and 17% for a clay loam, respectively. The field capacity level which occurs shortly after an irrigation event was considered the upper point of soil moisture content, and the lower point was the maximum soil water depletion level at 50% of plant available water capacity in the root zone, depending on crop type, root depth, growth stage and soil type. The lower thresholds of soil moisture content to trigger an irrigation event were 17% and 26% in the sandy loam and clay loam soils, respectively. The corresponding soil water potential readings from the WM sensors to initiate irrigation events were approximately 60 kPa and 105 kPa for sandy loam, and clay loam soils, respectively. Watermark sensors can be successfully used for irrigation scheduling by simply setting two levels of moisture content using soil-water characteristic curve data. Further, the wireless system can help farmers and irrigators monitor real-time moisture content in the soil root zone of their crops and determine irrigation scheduling remotely without time consuming, manual data logging and frequent visits to the field.

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