Determination of growing season soil water deficits on a forested slope using water balance analysis

1985 ◽  
Vol 15 (1) ◽  
pp. 107-114 ◽  
Author(s):  
D. G. Giles ◽  
T. A. Black ◽  
D. L. Spittlehouse
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Root Zone ◽  
Growing Season ◽  
Conifer Forest ◽  
Soil Water Retention ◽  
Water Balance Components ◽  
Water Deficits ◽  
Water Storage Capacity ◽  
Zone Depth

Coefficients for the calculation of soil water balance components at seven sites on a forested slope were determined using only measurements of daily solar irradiance, maximum and minimum air temperature and rainfall, and weekly root zone soil water content during a 2-year period. Site parameters required were root zone depth, soil water retention characteristics, and rainfall interception coefficients. Based on daytime net radiation, the Priestley–Taylor evapotranspiration coefficient (α) was found to be 0.73 ± 0.07, which is similar to values reported in other conifer forest studies. Growing season water deficit increased with decreasing root zone water storage capacity, which was mainly a function of root zone depth. A comparison between high and low elevations on the slope showed 100-year site indices ranging from 17 to 53 m corresponding to growing season soil water deficits during the driest year of the study, ranging from 79 to 4 mm. Basal area annual increments were found to be correlated with soil water deficits and growing season transpiration, both for the study period and when both variables were averaged over the last 18 years.

Estimation of Soil Water Balance Components Based on Continuous Soil Moisture Measurement and Inversed Richards Method in an Irrigated Agricultural Field of a Desert Oasis

2020 ◽  
Author(s):  
Hu Liu ◽  
Yang Yu ◽  
Zhongkai Li ◽  
Wenzhi Zhao ◽  
Qiyue Yang ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Soil Water ◽  
Estimation Method ◽  
Growing Season ◽  
Soil Water Balance ◽  
Richards Equation ◽  
Water Balance Components ◽  
Sustainable Water Resources Management ◽  
Irrigation Drainage

<p>An accurate assessment of soil water balance components (<em>SWBCs</em>) is necessary for improving irrigation strategies in any water-limited environment. However, quantitative information of <em>SWBCs</em> is usually challenging to obtain, because none of the components (i.e., irrigation, drainage, and evapotranspiration) can be easily measured under actual conditions. Soil moisture is a variable that integrates the water balance components of land surface hydrology, and the evolution of soil moisture is assumed to contain the memory of antecedent hydrologic fluxes, and thus can be used to determine <em>SWBCs</em> from a hydrologic balance. A database of soil moisture measurements from six experimental plots with different treatments in the middle Heihe River Basin of China was used to test the potential of a soil moisture database in estimating the <em>SWBCs</em>. We first compared the hydrophysical properties of the soils in these plots, such as vertical saturated hydraulic conductivity (<em>K</em><sub>s</sub>) and soil water retention features, for supporting the <em>SWBC</em> estimations. Then we determined evapotranspiration and other SWBCs through a method that combined the soil water balance method and the inverse Richards equation (a model of unsaturated soil water flow based on the Richards equation). To test the accuracy of our estimation, we used both indirect methods (such as power consumption of the pumping irrigation well, and published SWBCs values at nearby sites), and the water balance equation technique to verify the estimated <em>SWBCs</em> values, all of which showed a good reliability of our estimation method. Finally, the uncertainties of the proposed methods were analyzed to evaluate the systematic error of the <em>SWBC</em> estimation and any restrictions on its application. The results showed significant variances among the film-mulched plots in both the cumulative irrigation volumes (652.1~ 867.3 mm) and deep drainages (170.7~364.7 mm). Moreover, the unmulched plot had remarkably higher values in both cumulative irrigation volumes (1186.5 mm) and deep drainages (651.8 mm) compared with the mulched plots. Obvious correlation existed between the volume of irrigation and that of drained water. However, the ET demands for all the plots behaved pretty much the same, with the cumulative ET values ranging between 489.1 and 561.9 mm for the different treatments in 2016, suggesting that the superfluous irrigation amounts had limited influence on the accumulated ET throughout the growing season because of the poor water-holding capacity of the sandy soil. This work confirmed that relatively reasonable estimations of the <em>SWBCs</em> in coarse-textured sandy soils can be derived by using soil moisture measurements; the proposed methods provided a reliable solution over the entire growing season and showed a great potential for identifying appropriate irrigation amounts and frequencies, and thus a move toward sustainable water resources management, even under traditional surface irrigation conditions.</p>

scholarly journals Quantification of soil water balance components based on continuous soil moisture measurement and the Richards equation in an irrigated agricultural field of a desert oasis

2019 ◽  
Vol 23 (11) ◽  
pp. 4685-4706 ◽  
Author(s):  
Zhongkai Li ◽  
Hu Liu ◽  
Wenzhi Zhao ◽  
Qiyue Yang ◽  
Rong Yang ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Soil Water ◽  
Estimation Method ◽  
Growing Season ◽  
Soil Water Balance ◽  
Richards Equation ◽  
Water Balance Components ◽  
Sustainable Water Resources Management ◽  
Irrigation Drainage

Abstract. An accurate assessment of soil water balance components (SWBCs) is necessary for improving irrigation strategies in any water-limited environment. However, quantitative information on SWBCs is usually challenging to obtain, because none of the components (i.e., irrigation, drainage, and evapotranspiration) can be easily measured under actual conditions. Soil moisture is a variable that integrates the water balance components of land surface hydrology, and the evolution of soil moisture is assumed to contain the memory of antecedent hydrologic fluxes, and can thus be used to determine SWBCs from a hydrologic balance. A database of soil moisture measurements from six experimental plots with different treatments in the middle Heihe River basin of China was used to test the potential of a such a database for estimating SWBCs. We first compared the hydrophysical properties of the soils in these plots, such as vertical saturated hydraulic conductivity (Ks) and soil water retention features, for supporting SWBC estimations. We then determined evapotranspiration and other SWBCs using a method that combined the soil water balance method and the inverse Richards equation (a model of unsaturated soil water flow based on the Richards equation). To test the accuracy of our estimation, we used both indirect methods (such as power consumption of the pumping irrigation well and published SWBCs values at nearby sites) and the water balance equation technique to verify the estimated SWBCs values, all of which showed good reliability with respect to our estimation method. Finally, the uncertainties of the proposed methods were analyzed to evaluate the systematic error of the SWBC estimation and any restrictions regarding its application. The results showed significant variances among the film-mulched plots in both the cumulative irrigation volumes (652.1–867.3 mm) and deep drainages (170.7–364.7 mm). Moreover, the un-mulched plot had remarkably higher values in both cumulative irrigation volumes (1186.5 mm) and deep drainages (651.8 mm) compared with the mulched plots. Obvious correlation existed between the volume of irrigation and that of drained water. However, the ET demands for all of the plots behaved pretty much the same, with the cumulative ET values ranging between 489.1 and 561.9 mm for the different treatments in 2016, suggesting that the superfluous irrigation amounts had limited influence on the accumulated ET throughout the growing season due to the poor water-holding capacity of the sandy soil. This work confirmed that relatively reasonable estimations of the SWBCs in coarse-textured sandy soils can be derived by using soil moisture measurements; the proposed methods provided a reliable solution over the entire growing season and showed a great potential for identifying appropriate irrigation amounts and frequencies, and thus a move toward sustainable water resources management, even under traditional surface irrigation conditions.

Effect of Crop Geometry (Row Proportions) on the Water Balance of the Root Zone of a Pigeonpea and Rice Intercropping System

1988 ◽  
Vol 24 (3) ◽  
pp. 385-391 ◽  
Author(s):  
D. Jena ◽  
C. Misra
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Rainfall Intensity ◽  
Root Zone ◽  
Growing Season ◽  
Soil Water Depletion ◽  
Dry Spells ◽  
Dry Spell ◽  
The Mean ◽  
Crop Geometry

SUMMARYRice, pigeonpea and rice + pigeonpea systems (in the row proportions of 1:2 and 2:5) were compared. Soil water depletion and percolation were determined during selected dry spells and yields ascertained after harvest. The mean evapotranspiration rates of rice, pigeonpea, rice + pigeonpea (1:2) and rice + pigeonpea (2:5) were 0.28, 0.79, 0.40 and 0.35 cm d−1, respectively, during a dry spell around 60 days after sowing. In general low rainfall intensity and frequent dry spells in the growing season increased pigeonpea yield but depressed that of rice. Intercropping thus ensured yield stability and hence the profitability of the system as a whole.

Influence of Rice Husk - Mulch on Soil Water Balance Components under Sorghum and Millet Crops in Maiduguri, Semi Arid Northeast Nigeria

2019 ◽  
pp. 1-7
Author(s):  
P. C. Eze ◽  
A. J. Odofin ◽  
I. N. Onyekwere ◽  
J. J. Musa ◽  
P. A. Tsado
Keyword(s):  
Moisture Content ◽  
Water Balance ◽  
Soil Water ◽  
Rice Husk ◽  
Root Zone ◽  
Soil Water Balance ◽  
Annual Rainfall ◽  
Crop Evapotranspiration ◽  
Water Balance Components ◽  
Moisture Storage

A 2 x 3 factorial experiment was conducted at two sites in Maiduguri, Borno State during the 2009 cropping season. The objective was to evaluate the influence of rice husk-mulch on soil water balance components under sorghum and millet crops. The treatments comprised of two test crops (sorghum and millet) and three rates of application (0, 10 and 15 t ha-1) of rice husk mulch, fitted in a split-plot design. The test crops were assigned to the main plot, while the mulch application rates were assigned to the sub-plot. The treatments were replicated three times.  The components of soil water balance determined were annual rainfall, moisture storage within sorghum and millet root zone, drainage below crop root zone and seasonal crop evapotranspiration. Profile moisture content was measured weekly with the aid of a neutron probe installed at a depth of 2.0 m using access tubes. Also, soil (0 – 30 cm depth) moisture content was determined gravimetrically on weekly basis. Rainfall was measured using a manual rain gauge installed at each of the two sites. Findings in this study indicated that, under the prevailing circumstances, annual rainfall was lower than the amount observed over a ten-year period in Maiduguri. Consequently, soil moisture storage, drainage and seasonal crop evapotranspiration generally declined. An average of over 90 % of this low annual rainfall was lost as seasonal crop evapotranspiration. Sorghum plots stored higher moisture within the root zone, had higher drainage and lower seasonal evapotranspiration than millet plots. Moisture storage and drainage increased with increasing mulch application rate, while, seasonal crop evapotranspiration decreased with it.

scholarly journals Calculation of available water supply in crop root zone and the water balance of crops

2015 ◽  
Vol 45 (4) ◽  
pp. 285-298 ◽  
Author(s):  
Jan Haberle ◽  
Pavel Svoboda
Keyword(s):  
Water Balance ◽  
Water Supply ◽  
Soil Water ◽  
Root Zone ◽  
Potential Evapotranspiration ◽  
Pedotransfer Functions ◽  
Soil Water Retention ◽  
Available Water ◽  
Available Water Content ◽  
Access To Data

Abstract Determination of the water supply available in soils for crops is important for both the calculation of water balance and the prediction of water stress. An approach to calculations of available water content in layers of the root zone, depletion of water during growth, and water balance, with limited access to data on farms, is presented. Soil water retention was calculated with simple pedotransfer functions from the texture of soil layers, root depth, and depletion function were derived from observed data; and the potential evapotranspiration was calculated from the temperature. A comparison of the calculated and experimental soil water contents showed a reasonable fit.

Comparative assessment of soil water balance under wheat in a subtropical environment with simplified models

1997 ◽  
Vol 128 (4) ◽  
pp. 461-468 ◽  
Author(s):  
V. K. ARORA ◽  
CHARANJIT SINGH ◽  
KULDEEP SINGH
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Root Zone ◽  
Balance Model ◽  
Soil Water Storage ◽  
Water Evaporation ◽  
Deep Drainage ◽  
Water Balance Components ◽  
Area Index ◽  
Empirical Coefficients

Water balance components under wheat were assessed by employing two simple models, differing in their structure and data requirements, namely the soil-plant–atmosphere–water (SPAW) model of Saxton (1989) and the water balance model (WBM) of Arora et al. (1987). A few modifications based on the SPAW model procedure for the estimation of green canopy were used in a modified WBM and its performance was also tested. Soil water loss (the sum of interception evaporation, soil evaporation, plant transpiration and deep drainage) from sowing to harvest, simulated with the WBM, modified WBM and the SPAW model, had a close correspondence with the measured sum of profile water depletion, rainfall and irrigation for values ranging between 18·3 and 42·7 cm. Estimates of drainage with the WBM and modified WBM using empirical coefficients were greater than those calculated using the SPAW model for situations where the upward flow of water into the root-zone was negligible. Estimates of soil water evaporation using the WBM and modified WBM were invariably smaller than those using the SPAW model. A comparison of simulated and measured soil water storage and a correlation analysis of simulated transpiration with measured biomass at harvest showed that the performance of the WBM was the most realistic of the three models. However, it requires the input of leaf area index values to infer green canopy for each water supply regime. In the absence of this information, the modified WBM and SPAW models are more useful for assessing water balance components in cropped soils.

Soil water retention dynamics in a Mollisol during a maize growing season under contrasting tillage systems

2021 ◽  
Vol 209 ◽  
pp. 104953
Author(s):  
Xinjun Huang ◽  
Hengfei Wang ◽  
Meng Zhang ◽  
Rainer Horn ◽  
Tusheng Ren
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Growing Season ◽  
Soil Water Retention ◽  
Tillage Systems

scholarly journals Water and salt transport in daily irrigated root zone.

1987 ◽  
Vol 35 (3) ◽  
pp. 395-406
Author(s):  
C. Dirksen
Keyword(s):  
Soil Water ◽  
Water Uptake ◽  
Gamma Ray ◽  
Root Zone ◽  
Root Water Uptake ◽  
Salt Transport ◽  
Soil Water Retention ◽  
Transport Models ◽  
Leaching Fraction ◽  
Water Contents

With closed, high-frequency irrigation systems, the water supply can be tailored to the instant needs of plants. To be able to do this optimally, it is necessary to understand how plants interact with their environment. To study water uptake under a variety of non-uniform conditions in the root zone, lucerne was grown in laboratory soil columns with automated gamma ray attenuation, tensiometer and salinity sensor equipment to measure soil water contents, pressure potentials and osmotic potentials, respectively. The columns were irrigated with water of different salinity at various frequencies and leaching fractions. This paper presents results obtained in a column irrigated daily with water of conductivity 0.33 S/m (h0 = -13.2 m) at a target leaching fraction of 0.08. This includes the drying and wetting patterns under daily irrigations in deficit and excess of evapotranspiration, respectively. After 230 days the salination of the column had still not reached a steady state. Salinity increased rapidly with depth and root water uptake was shallow for the deep-rooting lucerne. Water and salt transport under daily irrigation cannot be described without taking hysteresis of soil water retention into account. The data presented are suitable for testing various water uptake models, once numerical water and salt transport models of the required complexity are operational. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Modelling of Soil Respiration in Hungary

2006 ◽  
Vol 55 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Ferenc Ács ◽  
H. Breuer
Keyword(s):  
Soil Respiration ◽  
Water Balance ◽  
Air Temperature ◽  
Sandy Loam ◽  
Growing Season ◽  
Biogeochemical Model ◽  
Clay Loam ◽  
Water Balance Components ◽  
Linear Relationships ◽  
Time Periods

The climatology of soil respiration in Hungary is presented. Soil respiration is estimated by a Thornthwaite-based biogeochemical model using soil hydrophysical data and climatological fields of precipitation and air temperature. Soil respiration fields are analyzed for different soil textures (sand, sandy loam, loam, clay loam and clay) and time periods (year, growing season and months).  Strong linear relationships were found between soil respiration and the actual evapotranspiration for annual and growing season time periods. In winter months soil respiration is well correlated with air temperature, while in summer months there is a quite variable relationship with water balance components. The strength of linear relationship between soil respiration and climatic variables is much better for coarser than for finer soil texture.

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