ESTIMATING EVAPOTRANSPIRATION FROM IRRIGATED CROPS IN SOUTHWESTERN ONTARIO

Several years of daily evapotranspiration (ET) data for irrigated early potatoes, corn and processing tomatoes, grown on Fox sandy loam measured by floating lysimeters and estimated by meteorological data were used to evaluate an equilibrium evapotranspiration (ETeq) model. A reasonable relationship was obtained between values estimated by the model and those measured by floating lysimeters. The ETeq model can be used to estimate daily ET over a wide range of soil moisture and foliage cover conditions. ETeq can be estimated from readily available climatic data in the form: ETeq = (0.48 + 0.01 Ta) [(0.114 + 0.365n/N) K↓a − 0.039]; where Ta is the mean daily air temperature (°C); n is sunshine duration (h); N is maximum hours of bright sunshine (h); K↓a is solar energy received at the top of the atmosphere (mm/day). At high soil water storage in the root zone, the ET/ETeq remained constant, whereas, at low soil water storage, the ET/ETeq decreased linearly with decreasing soil water storage. The total crop yields were directly related to growing season accumulated ET.

Download Full-text

Drainage and change in soil water storage below the root-zone under long fallow and continuous cropping sequences in the Victorian Mallee

Australian Journal of Agricultural Research ◽

10.1071/ar02079 ◽

2003 ◽

Vol 54 (7) ◽

pp. 663 ◽

Cited By ~ 10

Author(s):

Mark G. O'Connell ◽

Garry J. O'Leary ◽

David J. Connor

Keyword(s):

Soil Water ◽

Root Zone ◽

Sandy Loam ◽

Water Storage ◽

Soil Water Storage ◽

Annual Rainfall ◽

Continuous Cropping ◽

Deep Drainage ◽

Mean Annual Rainfall ◽

Fallow System

A field study investigated drainage and changes in soil water storage below the root-zone of annual crops on a sandy loam soil in the Victorian Mallee for 8 years. It was designed to compare the effects of the common long (18-month) fallow in a 3-year rotation (fallow–wheat–pea, FWP) with a rotation in which the fallow was replaced with mustard (Brassica juncea), viz. mustard–wheat–pea (MWP). Drainage was measured over 2 periods (1993–98 and 1998–2001) using 9 in situ drainage lysimeters in each rotation. The first period of ~5 years was drier than average (mean annual rainfall 298 cf. 339 mm) and drainage was low and variable. Drainage was greater under the fallow rotation (average 0.24 mm/year) than under the non-fallow rotation (average <0.01 mm/year). The result for the fallow rotation did, however, include one lysimeter that recorded substantial drainage (10.6 mm over the 5 years). During the second period of measurement (~3 years), rainfall was above average (mean annual rainfall 356 cf. 339�mm) and drainage was greater. On average, drainage from the fallow rotation was 6.7 mm/year compared with the non-fallow rotation at 4.0 mm/year. There was again substantial variation between lysimeters. One lysimeter under MWP recorded 31.4 mm/year, and as in the earlier drier period, there were many lysimeters that recorded no drainage. During the drier first period (1993–98), changes in soil water storage between 1.5 and 5.5 m depth confirmed the tendency of the fallow rotation to increase deep drainage. Despite increases and decreases in subsoil water storage during the study, the cumulative change in water storage was positive and greatest under FWP (range: 2.8–14.8 mm/year, ave. 9.6 mm/year) compared with MWP (range: 5.3–9.8 mm/year, ave. 7.4 mm/year) cropping sequences. Overall, the long fallow system has the potential to increase deep drainage by approximately 2 mm/year compared with a fully cropped system, over a wide annual rainfall range (134–438 mm). Further, this experiment reinforces the focus for the reduction of fallow practices for dryland salinity control in the Mallee region.

Download Full-text

Regression Models for Soil Water Storage Estimation Using the ESA CCI Satellite Soil Moisture Product: A Case Study in Northeast Portugal

Water ◽

10.3390/w13010037 ◽

2020 ◽

Vol 13 (1) ◽

pp. 37

Author(s):

Tomás de Figueiredo ◽

Ana Caroline Royer ◽

Felícia Fonseca ◽

Fabiana Costa de Araújo Schütz ◽

Zulimar Hernández

Keyword(s):

Soil Moisture ◽

Soil Water ◽

Regression Models ◽

Meteorological Data ◽

Water Storage ◽

Model Performance ◽

Soil Water Balance ◽

Soil Water Storage ◽

The Relationship

The European Space Agency Climate Change Initiative Soil Moisture (ESA CCI SM) product provides soil moisture estimates from radar satellite data with a daily temporal resolution. Despite validation exercises with ground data that have been performed since the product’s launch, SM has not yet been consistently related to soil water storage, which is a key step for its application for prediction purposes. This study aimed to analyse the relationship between soil water storage (S), which was obtained from soil water balance computations with ground meteorological data, and soil moisture, which was obtained from radar data, as affected by soil water storage capacity (Smax). As a case study, a 14-year monthly series of soil water storage, produced via soil water balance computations using ground meteorological data from northeast Portugal and Smax from 25 mm to 150 mm, were matched with the corresponding monthly averaged SM product. Linear (I) and logistic (II) regression models relating S with SM were compared. Model performance (r2 in the 0.8–0.9 range) varied non-monotonically with Smax, with it being the highest at an Smax of 50 mm. The logistic model (II) performed better than the linear model (I) in the lower range of Smax. Improvements in model performance obtained with segregation of the data series in two subsets, representing soil water recharge and depletion phases throughout the year, outlined the hysteresis in the relationship between S and SM.

Download Full-text

A decreasing trend in global soil water storage from 1981 to 2017

10.5194/egusphere-egu21-5756 ◽

2021 ◽

Author(s):

XinRui Luo ◽

Shaoda Li ◽

Wunian Yang ◽

Liang Liu ◽

Xiaolu Tang

Keyword(s):

Soil Water ◽

Water Loss ◽

Root Zone ◽

Carbon Sink ◽

Temporal Trends ◽

Water Storage ◽

Terrestrial Ecosystems ◽

Environmental Drivers ◽

Soil Water Storage ◽

Soil Drought

Soil water storage serves as a vital resource of the terrestrial ecosystems, and it can significantly influence water cycle and carbon cycling with the frequent occurrence of soil drought induced by land-atmosphere feedbacks. However, there are high variations and uncertainties of root zone soil water storage. This study applied comparison map profile (CMP), Mann-Kendall test, Theil-Sen estimate and partial correlation analysis to (1) estimate the global root zone (0~1 m) soil water storage, (2) and investigate the spatial and temporal patterns from 1981 to 2017 at the global scale, (3) and their relationships with environmental drivers (precipitation, temperature, potential evaportranspiration) using three soil moisture (SM) products &#8211; ERA-5, GLDAS and MERRA-2. Globally, the average annual soil water storage from 1981 to 2017 varied significantly, ranging from 138.3 (100 Pg a-1, 1 Pg = 1015 g) in GLDAS to 342.6 (100 Pg a-1) in ERA-5. Soil water storage of the three SM products consistently showed a decreasing trend. However, the temporal trend of soil water storage among different climate zones was different, showing a decreasing trend in tropical, temperate and cold zones, but an increasing trend in polar regions. On the other hand, temporal trends in arid regions differed from ERA-5, GLDAS and MERRA-2. Spatially, the SM products differed greatly, particularly for boreal areas with D value higher for 2500 Mg ha-1 a-1 and CC value lower for -0.2 between GLDAS and MERRA-2. Over 1981 to 2017, water storage of more than 50% of the global land area suffered from a decreasing trend, especially in Africa and Northeastern of China. Precipitation was the main dominated driver for variation of soil water storage, and distribution varied in different SM products. In conclusion, a global decreasing trend in soil water storage indicate a water loss from soils, and how the water loss affecting carbon sink in terrestrial ecosystems under ongoing climate change needs further investigation.

Download Full-text

Climate Change Made Major Contributions to Soil Water Storage Decline in the Southwestern US during 2003–2014

Water ◽

10.3390/w11091947 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1947

Author(s):

Jianzhao Liu ◽

Liping Gao ◽

Fenghui Yuan ◽

Yuedong Guo ◽

Xiaofeng Xu

Keyword(s):

Climate Change ◽

Soil Water ◽

Water Resource Management ◽

Time Series Data ◽

Meteorological Data ◽

Water Storage ◽

Climate Change Impacts ◽

Soil Water Storage ◽

Series Data ◽

Atmospheric Water

Soil water shortage is a critical issue for the Southwest US (SWUS), the typical arid region that has experienced severe droughts over the past decades, primarily caused by climate change. However, it is still not quantitatively understood how soil water storage in the SWUS is affected by climate change. We integrated the time-series data of water storage and evapotranspiration derived from satellite data, societal water consumption, and meteorological data to quantify soil water storage changes and their climate change impacts across the SWUS from 2003 to 2014. The water storage decline was found across the entire SWUS, with a significant reduction in 98.5% of the study area during the study period. The largest water storage decline occurred in the southeastern portion, while only a slight decline occurred in the western and southwestern portions of the SWUS. Net atmospheric water input could explain 38% of the interannual variation of water storage variation. The climate-change-induced decreases in net atmospheric water input predominately controlled the water storage decline in 60% of the SWUS (primarily in Texas, Eastern New Mexico, Eastern Arizona, and Oklahoma) and made a partial contribution in approximately 17% of the region (Central and Western SWUS). Climate change, primarily as precipitation reduction, made major contributions to the soil water storage decline in the SWUS. This study infers that water resource management must consider the climate change impacts over time and across space in the SWUS.

Download Full-text

Effects of summertime changes in weather and root-zone soil water storage on canopy CO2 flux and evapotranspiration of two juvenile Douglas-fir stands

Agricultural and Forest Meteorology ◽

10.1016/0168-1923(91)90049-v ◽

1991 ◽

Vol 53 (4) ◽

pp. 303-323 ◽

Cited By ~ 18

Author(s):

D.T. Price ◽

T.A. Black

Keyword(s):

Soil Water ◽

Root Zone ◽

Water Storage ◽

Co2 Flux ◽

Douglas Fir ◽

Soil Water Storage

Download Full-text

Effects of Wheat and Rapeseed Production on Soil Water Storage in Mongolian Rangeland

Agriculture ◽

10.3390/agriculture11090888 ◽

2021 ◽

Vol 11 (9) ◽

pp. 888

Author(s):

Katori Miyasaka ◽

Takafumi Miyasaka ◽

Jumpei Ota ◽

Siilegmaa Batsukh ◽

Undarmaa Jamsran

Keyword(s):

Soil Water ◽

Crop Production ◽

Root Zone ◽

Water Storage ◽

Soil Water Storage ◽

Matric Potential ◽

Wheat Field ◽

Long Time ◽

Rapeseed Production ◽

Wilting Point

In recent years, Mongolia has witnessed an increase in not only wheat fields, which have been present for a long time, but also rapeseed fields. This has led to increasing concerns about soil degradation due to inappropriate cultivation. This study aims to determine the impacts of rapeseed production on soil water storage in Mongolia. The soil water content and matric potential were measured in wheat and rapeseed fields and adjacent steppe rangeland for five years, including crop production and fallow years, and the soil water storages in the fields were compared. The results demonstrated that the matric potential below the root zone in the rapeseed field and both rangelands was drier than the wilting point, whereas the potential in the wheat field was usually almost the same or wetter than this point. The comparison of the amount of soil water storage during the fallow year with that of the adjacent rangeland showed it to be 5–10% higher for the wheat field and almost equal for the rapeseed field. Field management must consider the fact that rapeseed fields use more water than is required by wheat fields and that less water is stored during fallow periods.

Download Full-text

Water use of sunflower crops

Australian Journal of Experimental Agriculture ◽

10.1071/ea9790233 ◽

1979 ◽

Vol 19 (97) ◽

pp. 233 ◽

Cited By ~ 2

Author(s):

WK Anderson

Keyword(s):

Soil Water ◽

Water Use ◽

Root Zone ◽

Water Storage ◽

Soil Water Storage ◽

Evaporative Demand ◽

Sowing Time ◽

Small Component ◽

Water Storage Capacity ◽

Water Use Efficiencies

The potential, or energy-limited evapotranspiration, and the actual, or soil water-limited evapotranspiration functions of sunflower were estimated by lysimetry and field soil water measurements. The functions show that peak water demand by the crop is in the immediate post-anthesis period and that sunflower is capable of restricting its water use when some 70% of the maximum available water remains in the root zone. With the aid of these functions, weekly estimates were made of the water use of thirteen commercial sunflower crops in northern New South Wales. Estimated water use ranged from 150 to 320 mrn and water use efficiencies from 1.9 to 10.5 kg seed mm-1 water used. Highest yields and water use efficiencies were associated with a combination of high total water supply (soil water at sowing plus rainfall during growth of 380 mm or more) high water use (220 mm or more) and low evaporative demand (below 780 mm of pan evaporation). Based on the water use characteristics of the crop the optimal sowing time in most areas is mid summer. However, spring sowings may be preferable for winter rainfall areas where soil water storage capacity is high and there is only a small component of summer rain. Crops sown in spring, even with high stored soil water (up to 200 mm) failed to yield as well as those sown in summer with much lower soil water storage.

Download Full-text

Comparison between climatological and field water balances for a coffee crop

Scientia Agricola ◽

10.1590/s0103-90162007000300001 ◽

2007 ◽

Vol 64 (3) ◽

pp. 215-220 ◽

Cited By ~ 7

Author(s):

Isabeli Pereira Bruno ◽

Adriana Lúcia da Silva ◽

Klaus Reichardt ◽

Durval Dourado-Neto ◽

Osny Oliveira Santos Bacchi ◽

...

Keyword(s):

Soil Water ◽

Root Zone ◽

Water Storage ◽

Crop Management ◽

Soil Water Storage ◽

Water Runoff ◽

Available Water ◽

Water Balances ◽

Runoff Losses

The use of climatological water balances in substitution to complete water balances directly measured in the field allows a more practical crop management, since the climatological water balances are based on data monitored as a routine. This study makes a comparison between these methods in terms of estimatives of evapotranspiration, soil water storage, soil available water, runoff losses, and drainage below root zone, during a two year period, taking as an example a coffee crop of the variety Catuaí, three to five years old. Climatological water balances based on the estimation of the evapotranspiration through the methods of Thornthwaite and Penman-Monteith, can reasonably substitute field measured balances, however underestimating the above mentioned variables.

Download Full-text

Effects of Frozen Soil on Snowmelt Runoff and Soil Water Storage at a Continental Scale

Journal of Hydrometeorology ◽

10.1175/jhm538.1 ◽

2006 ◽

Vol 7 (5) ◽

pp. 937-952 ◽

Cited By ~ 248

Author(s):

Guo-Yue Niu ◽

Zong-Liang Yang

Keyword(s):

Thermal Properties ◽

Soil Water ◽

Liquid Water ◽

Water Storage ◽

Frozen Soil ◽

Soil Water Storage ◽

Continental Scale ◽

Community Land Model ◽

Wide Range ◽

Ice Content

Abstract The presence of ice in soil dramatically alters soil hydrologic and thermal properties. Despite this important role, many recent studies show that explicitly including the hydrologic effects of soil ice in land surface models degrades the simulation of runoff in cold regions. This paper addresses this dilemma by employing the Community Land Model version 2.0 (CLM2.0) developed at the National Center for Atmospheric Research (NCAR) and a simple TOPMODEL-based runoff scheme (SIMTOP). CLM2.0/SIMTOP explicitly computes soil ice content and its modifications to soil hydrologic and thermal properties. However, the frozen soil scheme has a tendency to produce a completely frozen soil (100% ice content) whenever the soil temperature is below 0°C. The frozen ground prevents infiltration of snowmelt or rainfall, thereby resulting in earlier- and higher-than-observed springtime runoff. This paper presents modifications to the above-mentioned frozen soil scheme that produce more accurate magnitude and seasonality of runoff and soil water storage. These modifications include 1) allowing liquid water to coexist with ice in the soil over a wide range of temperatures below 0°C by using the freezing-point depression equation, 2) computing the vertical water fluxes by introducing the concept of a fractional permeable area, which partitions the model grid into an impermeable part (no vertical water flow) and a permeable part, and 3) using the total soil moisture (liquid water and ice) to calculate the soil matric potential and hydraulic conductivity. The performance of CLM2.0/SIMTOP with these changes has been tested using observed data in cold-region river basins of various spatial scales. Compared to the CLM2.0/SIMTOP frozen soil scheme, the modified scheme produces monthly runoff that compares more favorably with that estimated by the University of New Hampshire–Global Runoff Data Center and a terrestrial water storage change that is in closer agreement with that measured by the Gravity Recovery and Climate Experiment (GRACE) satellites.

Download Full-text