scholarly journals Rapid selection of a representative monitoring location of soil water content for irrigation scheduling using surface moisture-density gauge

2016 ◽  
Vol 30 (4) ◽  
pp. 483-491 ◽  
Author(s):  
Ibrahim Mubarak ◽  
Mussadak Janat ◽  
Mohsen Makhlouf ◽  
Altayeb Hamdan
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Irrigation Scheduling ◽  
Time Stability ◽  
Agricultural Water Management ◽  
Surface Moisture ◽  
Fine Soil ◽  
Before And After ◽  
The Relationship

Abstract Establishing a representative monitoring location of soil water content is important for agricultural water management. One of the challenges is to develop a field protocol for determining such a location with minimum costs. In this paper, we use the concept of time stability in soil water content to examine whether using a short term monitoring period is sufficient to identify a representative site of soil water content and, therefore, irrigation scheduling. Surface moisture-density gauge was used as a means for measuring soil water content. Variations of soil water content in space and time were studied using geostatistical tools. Measuring soil water content was made at 30 locations as nodes of a 6×8 m grid, six times during the growing season. A representative location for average soil water content estimation was allocated at the beginning of a season, and thereafter it was validated. Results indicated that the spatial pattern of soil water content was strongly temporally stable, explained by the relationship between soil water content and fine soil texture. Two field surveys of soil water content, conducted before and after the 1st irrigation, could be sufficient to allocate a representative location of soil water content, and for adequate irrigation scheduling of the whole field. Surface moisture-density gauge was found to be efficient for characterising time stability of soil water content under irrigated field conditions.

Evapotranspiration Measurement and Irrigation Scheduling for Several Tropical Fruit Crops Using the EnviroScan System

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 549f-550
Author(s):  
Mongi Zekri ◽  
Bruce Schaffer ◽  
Stephen K. O'Hair ◽  
Roberto Nunez-Elisea ◽  
Jonathan H. Crane
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Use ◽  
National Parks ◽  
Quantitative Information ◽  
Irrigation Scheduling ◽  
Management Tool ◽  
Fruit Crops ◽  
Tropical Fruit

In southern Florida, most tropical fruit crops between Biscayne and Everglades National Parks are irrigated at rates and frequencies based on experience and observations of tree growth and fruit yield rather than on reliable quantitative information of actual water use. This approach suggests that irrigation rates may be excessive and could lead to leaching of agricultural chemicals into the groundwater in this environmentally sensitive area. Therefore, a study is being conducted to increase water use efficiency and optimize irrigation by accurately scheduling irrigation using a very effective management tool (EnviroScan, Sentek Environmental Innovations, Pty., Kent, Australia) that continuously monitors soil water content with highly accurate capacitance multi-sensor probes installed at several depths within the soil profile. The system measures crop water use by monitoring soil water depletion rates and allows the maintenance of soil water content within the optimum range (below field capacity and well above the onset of plant water stress). The study is being conducted in growers' orchards with three tropical fruit crops (avocado, carambola, and `Tahiti' lime) to facilitate rapid adoption and utilization of research results.

scholarly journals Time Stability of Soil Water Content

10.5772/52469 ◽  
2013 ◽  
Author(s):  
Wei Hu ◽  
Lindsay K. ◽  
Asim Biswas ◽  
Bing Cheng
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Time Stability

scholarly journals Estimating spatially distributed soil water content at small watershed scales based on decomposition of temporal anomaly and time stability analysis

2016 ◽  
Vol 20 (1) ◽  
pp. 571-587 ◽  
Author(s):  
W. Hu ◽  
B. C. Si
Keyword(s):  
Stability Analysis ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Spatial Patterns ◽  
Watershed Scale ◽  
Small Watershed ◽  
Time Stability ◽  
Spatially Distributed ◽  
Space Variant

Abstract. Soil water content (SWC) is crucial to rainfall-runoff response at the watershed scale. A model was used to decompose the spatiotemporal SWC into a time-stable pattern (i.e., temporal mean), a space-invariant temporal anomaly, and a space-variant temporal anomaly. The space-variant temporal anomaly was further decomposed using the empirical orthogonal function (EOF) for estimating spatially distributed SWC. This model was compared to a previous model that decomposes the spatiotemporal SWC into a spatial mean and a spatial anomaly, with the latter being further decomposed using the EOF. These two models are termed the temporal anomaly (TA) model and spatial anomaly (SA) model, respectively. We aimed to test the hypothesis that underlying (i.e., time-invariant) spatial patterns exist in the space-variant temporal anomaly at the small watershed scale, and to examine the advantages of the TA model over the SA model in terms of the estimation of spatially distributed SWC. For this purpose, a data set of near surface (0–0.2 m) and root zone (0–1.0 m) SWC, at a small watershed scale in the Canadian Prairies, was analyzed. Results showed that underlying spatial patterns exist in the space-variant temporal anomaly because of the permanent controls of static factors such as depth to the CaCO3 layer and organic carbon content. Combined with time stability analysis, the TA model improved the estimation of spatially distributed SWC over the SA model, especially for dry conditions. Further application of these two models demonstrated that the TA model outperformed the SA model at a hillslope in the Chinese Loess Plateau, but the performance of these two models in the GENCAI network (∼  250 km2) in Italy was equivalent. The TA model can be used to construct a high-resolution distribution of SWC at small watershed scales from coarse-resolution remotely sensed SWC products.

The relationship between solar radiation interception and soil water content in a tropical deciduous forest in Mexico

CATENA ◽  
1999 ◽  
Vol 36 (1-2) ◽  
pp. 153-164 ◽  
Author(s):  
L Galicia ◽  
J López-Blanco ◽  
A.E Zarco-Arista ◽  
V Filips ◽  
F Garcı́a-Oliva
Keyword(s):  
Solar Radiation ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Deciduous Forest ◽  
Tropical Deciduous Forest ◽  
Radiation Interception ◽  
The Relationship

scholarly journals Canopy Solar-Induced Chlorophyll Fluorescence and Its Link to Transpiration in a Temperate Evergreen Needleleaf Forest during the Fall Transition

Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 74
Author(s):  
Weiwei Cong ◽  
Kaijie Yang ◽  
Feng Wang
Keyword(s):  
Chlorophyll Fluorescence ◽  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Air Temperature ◽  
Pearson Correlation ◽  
Evergreen Forest ◽  
Spatiotemporal Resolution ◽  
The Relationship

Northern hemisphere evergreen needleleaf forest (ENF) contributes a significant fraction of global water exchange but regional transpiration (T) observation in ENF ecosystems is still challenging. Traditional remote sensing techniques and terrestrial biosphere models reproduce the transpiration seasonality with difficulty, and with large uncertainties. Solar-induced chlorophyll fluorescence (SIF) emission from vegetation correlates to photosynthesis at multiple spatial and temporal scales. However, how SIF links to transpiration of evergreen forest during seasonal transition is unclear. Here, we explored the relationship between canopy SIF and T retrieved from ground observation towers in ENF. We also examined the role of meteorological and soil factors on the relationship between SIF and T. A slow decrease of SIF and T with a fast reduction in photosynthetically active radiation (PAR), air temperature, vapor pressure deficit (VPD), soil temperature and soil water content (SWC) were found in the ENF during the fall transition. The correlation between SIF and T at hourly and daily scales varied significantly among different months (Pearson correlation coefficient = 0.29–0.68, p < 0.01). SIF and T were significantly linearly correlated at hourly (R2 = 0.53, p < 0.001) and daily (R2 = 0.67, p < 0.001) timescales in the October. Air temperature and PAR were the major moderating factors for the relationship between SIF and T in the fall transition. Soil water content (SWC) influenced the SIF-T relationship at an hourly scale. Soil temperature and VPD’s effect on the SIF-T relationship was evident at a daily scale. This study can help extend the possibility of constraining ecosystem T by SIF at an unprecedented spatiotemporal resolution during season transitions.

scholarly journals Limitations in Validating Derived Soil Water Content from Thermal/Optical Measurements Using the Simplified Triangle Method

2020 ◽  
Vol 12 (7) ◽  
pp. 1155 ◽  
Author(s):  
Abba Aliyu Kasim ◽  
Toby Nahum Carlson ◽  
Haruna Shehu Usman
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Surface Soil ◽  
Optical Measurements ◽  
Field Site ◽  
Surface Moisture ◽  
Thermal Measurements ◽  
Triangle Method ◽  
Good Agreement

We assess the validity of the surface moisture availability parameter (Mo) derived from satellite-based optical/thermal measurements using the simplified triangle method. First, we show that Mo values obtained from the simplified triangle method agree closely with those generated from a soil/vegetation/atmosphere/transfer (SVAT) model for scenes over a field site at the Allahabad district, India. Next, we compared Mo values from the simplified triangle method for these same overpass scenes with surface soil water content measured at depths of 5 and 15 cm at this field site. Although a very weak correlation exists between remotely sensed values of Mo for the full scenes and measured soil water content measured at both depths, correlations increasingly improve for the 5 cm samples (but not for the 15 cm samples) as pixels were limited to increasingly smaller vegetation fractions. We conclude that the simplified triangle method would yield reasonable values of Mo and demonstrate good agreement with ground measurements, provided that validation is limited to pixels with little or no vegetation and to soil depths of 5 cm or less.

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