Soil water status and water table depth modelling using electromagnetic surveys for precision irrigation scheduling

Geoderma ◽  
2013 ◽  
Vol 199 ◽  
pp. 22-29 ◽  
Author(s):  
C.B. Hedley ◽  
P. Roudier ◽  
I.J. Yule ◽  
J. Ekanayake ◽  
S. Bradbury
Keyword(s):  
Soil Water ◽  
Water Table ◽  
Water Status ◽  
Irrigation Scheduling ◽  
Water Table Depth ◽  
Soil Water Status ◽  
Precision Irrigation ◽  
Electromagnetic Surveys

Root-weighted soil water status for plant water deficit index based irrigation scheduling

2017 ◽  
Vol 189 ◽  
pp. 137-147 ◽  
Author(s):  
Xun Wu ◽  
Wenjing Zhang ◽  
Wen Liu ◽  
Qiang Zuo ◽  
Jianchu Shi ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Deficit ◽  
Water Status ◽  
Irrigation Scheduling ◽  
Plant Water ◽  
Soil Water Status ◽  
Plant Water Deficit

Assessing canopy temperature-based water stress indices for soybeans under subhumid conditions

2020 ◽  
Author(s):  
Angela Morales Santos ◽  
Reinhard Nolz
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Water Status ◽  
Canopy Temperature ◽  
Irrigation Scheduling ◽  
Stress Index ◽  
Crop Water ◽  
Stress Indices ◽  
Soil Water Status ◽  
Crop Water Stress

<p>Sustainable irrigation water management is expected to accurately meet crop water requirements in order to avoid stress and, consequently, yield reduction, and at the same time avoid losses of water and nutrients due to deep percolation and leaching. Sensors to monitor soil water status and plant water status (in terms of canopy temperature) can help planning irrigation with respect to time and amounts accordingly. The presented study aimed at quantifying and comparing crop water stress of soybeans irrigated by means of different irrigation systems under subhumid conditions.</p><p>The study site was located in Obersiebenbrunn, Lower Austria, about 30 km east of Vienna. The region is characterized by a mean temperature of 10.5°C with increasing trend due to climate change and mean annual precipitation of 550 mm. The investigations covered the vegetation period of soybean in 2018, from planting in April to harvest in September. Measurement data included precipitation, air temperature, relative humidity and wind velocity. The experimental field of 120x120 m<sup>2</sup> has been divided into four sub-areas: a plot of 14x120 m<sup>2</sup> with drip irrigation (DI), 14x120 m<sup>2</sup> without irrigation (NI), 36x120 m<sup>2</sup> with sprinkler irrigation (SI), and 56x120 m<sup>2</sup> irrigated with a hose reel boom with nozzles (BI). A total of 128, 187 and 114 mm of water were applied in three irrigation events in the plots DI, SI and BI, respectively. Soil water content was monitored in 10 cm depth (HydraProbe, Stevens Water) and matric potential was monitored in 20, 40 and 60 cm depth (Watermark, Irrometer). Canopy temperature was measured every 15 minutes using infrared thermometers (IRT; SI-411, Apogee Instruments). The IRTs were installed with an inclination of 45° at 1.8 m height above ground. Canopy temperature-based water stress indices for irrigation scheduling have been successfully applied in arid environments, but their use is limited in humid areas due to low vapor pressure deficit (VPD). To quantify stress in our study, the Crop Water Stress Index (CWSI) was calculated for each plot and compared to the index resulting from the Degrees Above Canopy Threshold (DACT) method. Unlike the CWSI, the DACT method does not consider VPD to provide a stress index nor requires clear sky conditions. The purpose of the comparison was to revise an alternative method to the CWSI that can be applied in a humid environment.</p><p>CWSI behaved similar for the four sub-areas. As expected, CWSI ≥ 1 during dry periods (representing severe stress) and it decreased considerably after precipitation or irrigation (representing no stress). The plot with overall lower stress was BI, producing the highest yield of the four plots. Results show that DACT may be a more suitable index since all it requires is canopy temperature values and has strong relationship with soil water measurements. Nevertheless, attention must be paid when defining canopy temperature thresholds. Further investigations include the development and test of a decision support system for irrigation scheduling combining both, plant-based and soil water status indicators for water use efficiency analysis.</p>

EFFECT OF SOIL WATER STATUS AND STRENGTH ON TRAFFICABILITY

1979 ◽  
Vol 59 (3) ◽  
pp. 313-324 ◽  
Author(s):  
C. L. PAUL ◽  
J. DE VRIES
Keyword(s):  
Soil Water ◽  
Water Table ◽  
Structural Damage ◽  
Water Status ◽  
Water Table Depth ◽  
Silty Clay ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
Soil Water Tension ◽  
Farm Vehicles

Trafficability tests with typical farm vehicles were carried out on three lowland fields at various degrees of wetness. Structural damage after the first and third passes was assessed in terms of bulk density, aeration porosity, pore-size distribution and rut depth. These indices could not be used per se as criteria for trafficable conditions because of lack of information concerning their relationship to plant growth. Instead, a trafficability criterion oriented toward traction efficiency was established by determining for each soil the relationship between its strength (assessed with a cone penetrometer) and traction efficiency measured by wheelslip. A critical value of strength for trafficability was inferred from this relationship. This was then used to obtain soil water tension limits for trafficability from known relations between tension and strength. Soil strength was found to be linearly dependent upon water table depth in spring when evapotranspiration was small and when the water table depth was less than 80 cm. Consideration of these relationships led to the establishment of critical water table limits for trafficability. These were 53, 45, and 60 cm for Lumbum muck, Hallart silty clay loam (SiCL) (grassland), and Hallart silty clay loam (cultivated), respectively.

Modelling soil water status for irrigation scheduling in potatoes II. Validation

1993 ◽  
Vol 23 (4) ◽  
pp. 343-358 ◽  
Author(s):  
Gurmeet Singh ◽  
D.M. Brown ◽  
A.G. Barr ◽  
R. Jung
Keyword(s):  
Soil Water ◽  
Water Status ◽  
Irrigation Scheduling ◽  
Soil Water Status

scholarly journals Irrigation Scheduling for Agriculture in the United States: The Progress Made and the Path Forward

2020 ◽  
Vol 63 (5) ◽  
pp. 1603-1618
Author(s):  
Saleh Taghvaeian ◽  
Allan A. Andales ◽  
L. Niel Allen ◽  
Isaya Kisekka ◽  
Susan A. O’Shaughnessy ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Status ◽  
The United States ◽  
Irrigation Scheduling ◽  
Crop Modeling ◽  
Soil Water Status ◽  
The Past ◽  
Plant Characteristics ◽  
Scheduling Strategies ◽  
Made In

HighlightsThe progress made in agricultural irrigation scheduling in the past ten years and the current challenges are discussed.The main scientific scheduling strategies are based on soil water status, plant characteristics, and crop modeling.Challenges include large time and data requirements and availability of decision support systems.Opportunities include integration of scheduling strategies and demonstrating their effectiveness through local studies.Abstract. Irrigation scheduling is the process of determining the appropriate amount and timing of water application to achieve desired crop yield and quality, maximize water conservation, and minimize possible negative effects on the environment, such as nutrient leaching below the crop root zone. Effective irrigation scheduling has been shown to save water, save energy, and help agricultural producers achieve improved yields and quality. However, scientific irrigation scheduling methods generally have remained limited to mostly research applications with relatively low adoption by irrigators. There are several main approaches to irrigation scheduling, including those based on soil water status, plant characteristics, and/or crop modeling. Each of these approaches has advantages as well as limitations and sources of uncertainty and variability, depending on application conditions. This article summarizes progress made in the U.S. in each of the main scheduling approaches in the past ten years (since the 2010 Decennial Irrigation Symposium) and existing challenges and opportunities that should be considered moving forward. This article is intended to guide future research and extension projects in improving adoption of scientific irrigation scheduling approaches. Keywords: Computer modeling, Plant characteristics, Soil water status.

Numerical investigation of irrigation scheduling based on soil water status

2011 ◽  
Vol 31 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Sharon Dabach ◽  
Naftali Lazarovitch ◽  
Jirka Šimůnek ◽  
Uri Shani
Keyword(s):  
Numerical Investigation ◽  
Soil Water ◽  
Water Status ◽  
Irrigation Scheduling ◽  
Soil Water Status
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