soil water Articles
-
Soil water thermal liquid diffusivity
The background of the thermal liquid diffusivity (TLD) concept was reviewed. Application of TLD to matric-head-based equations for water flow when a thermal gradient is present have been contradictory to the original development by Philip and de Vries (PdV). Beginning from Darcy's law for liquid water transport and Fick's law for water vapor transport was the foundational and well-known approach ...
-
Temperature Dependence of Soil Water Potential
To understand the process of coupled heat and water transport, the relationship between temperature and soil water potential must be known. Two clays, Avonlea bentonite and Lake Agassiz clay, are being considered as the clay-based sealing materials for the Canadian nuclear fuel waste disposal vault. Avonlea bentonite is distinguished from Lake Agassiz clay by its high sealing potential in water. ...
-
Soil water reserve estimation and vegetation relationships in a Mediterranean sub-humid forested catchment
A simple water balance model was used to calculate soil water reserve in a Mediterranean forested catchment. The relationship between soil water reserve and leaf water potential and stem water content was analysed. The usefulness of these variables as plant water status indicators was tested. The analyses were developed with a seven-year-long database (2001–2007) in the case of soil water content ...
-
Performance Evaluation of Selected Soil Moisture Sensors
Abstract Irrigation water management practices could greatly benefit from using soil moisture sensors that accurately measure soil water content or potential. Therefore, an assessment on soil moisture sensor reading accuracy is important. In this study, a performance evaluation of selected sensor calibration was performed considering factory- laboratory- and field-based calibrations. The selected ...
-
An alternate wetting and moderate soil drying regime improves root and shoot growth in rice
A major challenge in rice (Oryza sativa L.) production is to achieve the dual goal of increasing food production and saving water. This study aimed to investigate if alternate wetting and drying regimes could improve root and shoot growth and consequently increase grain yield and water use efficiency (WUE). Two rice varieties were field-grown at Yangzhou, China in 2005 and 2006. Three irrigation ...
-
Weighing lysimeters for evapotranspiration research on clay soil
Local crop evapotranspiration (ET) measurements are needed for northeastern Louisiana. Objectives were to install, calibrate, and assess soil water characteristics of paired weighing lysimeters at Saint Joseph, LA. Installed in 2005, the lysimeters have inner tanks 1.5 m long, 1.5 m deep, and 1.0 m wide that rest on load cells within outer tanks. The inner tanks contain refilled Sharkey clay ...
-
Hydrological effects of revegetation on hillsides - Case Study
Project Hydrological effects of revegetation on hillsides in the Baviaanskloof, South Africa Carried out by Marjan Sommeijer Country South Africa Background research Marjan Sommeijer travelled to Baviaanskloof in South Africa in 2010 to conduct research for her placement as part of her Bachelor’s degree in International Land and Water Management at Wageningen University. The ...
-
Postanthesis moderate wetting drying improves both quality and quantity of rice yield
A major challenge in rice (Oryza sativa L.) production in China is to cope with a declining availability of fresh water without compromising grain yield and grain quality. This study was designed to determine if alternate wetting and moderate soil drying during grain filling could maintain grain yield and grain quality. Two rice cultivars, Zhendao 88 (japonica) and Shanyou 63 (indica), were ...
-
Soil Water Sensors for Agriculture – Theory and Issues
Soil water sensors have been used for irrigation and water management in agriculture for many years, but with limited success in many cases. Nonetheless, the use of soil water sensors in increasing as water scarcity increases and, conversely, problems associated with over irrigation also increase. Common problems with soil water sensing included sensor failure, problems with wiring, lack of or ...
-
Soil water movement under a drip irrigation double-point source
Particularly in dry regions, the scarcity of high-quality fresh water has heightened the importance of urban runoff water re-use, leading as well to the improvement of water use efficiency through the surface drip irrigation method. Given the limited research on wetting front migration under a surface drip irrigation emitter, soil water movement under a double-point-source irrigation emitter ...
-
Effect of N-(n-butyl) Thiophosphoric Triamide and 3,4 Dimethylpyrazole Phosphate on gaseous emissions from grasslands under different soil water contents
The intensification of grassland systems is leading to serious environmental risks due to the large input of nitrogen (N) in fertilizers and the subsequent gaseous losses. Addition of nitrification inhibitors (NI) or urease activity inhibitors to fertilizers could reduce these losses to the atmosphere. In the present study, the effects of the nitrification inhibitor 3,4-dimethylpyrazole phosphate ...
-
Yield and water use response of cuphea to irrigation in the Northern Corn belt
Cuphea (Cuphea viscosissima Jacq. x C. lanceolata W.T. Aiton) may be prone to drought stress, yet little is known about the yield response of this new oilseed crop to irrigation. A field study was conducted in western Minnesota on a Barnes loam soil (fine-loamy, mixed, superactive, frigid Calcic Hapludolls) in 2002 and 2003 to compare yield and water use of irrigated and nonirrigated cuphea. ...
-
Nitrous oxide production in an eastern corn belt soil: sources and redox range
Nitrous oxide derived from soils is a main contributor to the greenhouse gas effect and a precursor to ozone-depleting substrates; however, the source processes and interacting controls are not well established. This study was conducted to estimate the magnitude and source (nitrification vs. denitrification) of N2O production as affected by the form of N fertilizer, soil water content, and redox ...
-
Effects of silicon and drought stress on tuber yield and leaf biochemical characteristics in potato
Silicon has beneficial effects on many crops, mainly under biotic and abiotic stresses. Silicon can affect biochemical, physiological, and photosynthetic processes and, consequently, alleviates drought stress. However, the effects of Si on potato (Solanum tuberosum L.) plants under drought stress are still unknown. The objective of this study was to evaluate the effect of Si supply on some ...
-
Canopy gas exchange measurements of cotton in an open system
A portable, open transparent chamber system for measuring canopy gas exchanges was developed and tested. Differentials between incoming and outgoing atmospheric H2O and CO2 concentrations were used to calculate canopy transpiration (E) and net assimilation (A) at 10-s intervals using solenoid valve actuated sample lines connected to an infrared gas analyzer. A programmable data logger controlled ...
-
Environmental impacts of community-based forest management in the Philippines
Community-based forest management (CBFM) is a major strategy in managing forest lands in the Philippines. Forest and land management activities implemented in CBFM project sites include management of tropical forests (enrichment planting, timber stand improvement or TSI and limited harvesting), rehabilitation of degraded lands (reforestation, assisted natural regeneration (ANR)) and agroforestry. ...
-
Soil CO2 Flux Measurements -- Addressing Spatial Variability: Determining the Number of Readings Required
Soils can be highly variable in terms of CO2 flux values. Even at a seemingly uniform site, the soil CO2 flux might range from 2 μmol/m2/s at one location to over 4 mol/m2/s just a few meters away. To obtain reliable site mean flux values, it is important to determine how many readings might be required so that time and resources can be properly allocated before starting an investigation. In ...
By LI-COR
-
Aquacrop—the FAO crop model to simulate yield response to water
This article introduces the FAO crop model AquaCrop. It simulates attainable yields of major herbaceous crops as a function of water consumption under rainfed, supplemental, deficit, and full irrigation conditions. The growth engine of AquaCrop is water-driven, in that transpiration is calculated first and translated into biomass using a conservative, crop-specific parameter: the biomass water ...
-
Effect of deficit irrigation and fertilization on cucumber
Soil water budgets are essential in determining the proper timing and amount of irrigation. Organic fertilizers can be substituted for commercial fertilizers; however, information is sparse on the interaction of irrigation management and nutrient source on cucumber (Cucumis sativus L.) production. This study evaluated nutrient source and irrigation management on growth and yield of cucumber grown ...
-
Soil tensiometer
What is a soil tensimeter? Soil tensimeter uses the principle of negative pressure to measure soil moisture and studies soil moisture movement from the perspective of energy. Transparent PVC pipe can clearly see the amount of water, low-end with high-quality clay head, fast sealing, accurate measurement. Soil tensiometer is a practical method to measure soil condition by using a negative pressure ...
Need help finding the right suppliers? Try XPRT Sourcing. Let the XPRTs do the work for you