Results 201 to 210 of about 292,207 (255)

Interpretation of lysimeter weighing data affected by wind

Journal of Plant Nutrition and Soil Science, 2013
AbstractWeighing lysimeters are valuable devices for measuring water‐balance components with high temporal resolution and high accuracy. However, some older lysimeter facilities still operate with lever‐arm‐counterbalance weighing systems that are sensitive to disturbances, e.g., forces exerted by wind.
Reinhard Nolz, Gerhard Kammerer, Peter Cepuder   +2 more
openaire   +1 more source

An electrically-weighed lysimeter for measuring evaporation rates

Agricultural Meteorology, 1968
Abstract An electrically-weighed lysimeter using electrical resistance strain gauges has been developed to measure the daily and diurnal rates of evaporation of water from crop and/or soil surfaces. The lysimeter, with a plan area of 0.4 m 2 , records changes of weight of the order of 20 g (equivalent to 0.05 mm depth of water) over a range of 20 kg ...
openaire   +1 more source

Development and evaluation of continuously weighing mini-lysimeters

Agricultural and Forest Meteorology, 1992
Grimmond, C.S.B., Isard, S.A. and Belding, M.J., 1992. Development and evaluation of continuously weighing mini-lysimeters. Agric. For. Meteorol., 62: 205-218. Micrometeorological methods for measuring evapotranspiration are based on the assumption that the water vapor flux is constant with respect to height within the first few meters above the ground,
C.Susan B. Grimmond, Scott A. Isard, Mark J. Belding   +2 more
openaire   +1 more source

ASIMPLIFIED WEIGHING LYSIMETER FOR MONOLITHIC OR RECONSTRUCTED SOILS

Applied Engineering in Agriculture, 1998
A simplified weighing lysimeter applicable to both monolithic and reconstructed soils was developed and tested in two lysimeters installed at Ismailia, Egypt and one installed at Bushland, Texas, USA. A monolithic lysimeter was used to measure reference grass evapotranspiration (ET) at Bushland because the dense subsoil and calcic horizon of the ...
null A. D. Schneider, null T. A. Howell, null A. T. A. Moustafa, null S. R. Evett, null W. Abou-Zeid   +4 more
openaire   +1 more source

Sources of Error in Hydraulic Weighing Lysimeter Measurements

Transactions of the ASAE, 1989
ABSTRACT HYDRAULIC weighing lysimeters are widely used for determining rates of evapotranspiration of agricultural crops. Some lysimeter systems have been modified to reduce temperature errors by placing the indicating manometer below ground level where temperature fluctuations are minimized or by using dummy mechanisms to allow for temperature-induced
null E. Gordon Kruse, null Christopher M. U. Neale   +1 more
openaire   +1 more source

Weighing Lysimeters for Evapotranspiration Research on Clay Soil

Agronomy Journal, 2009
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.
Ernest L. Clawson, Sean A. Hribal, Giovanni Piccinni, Robert L. Hutchinson, Robert V. Rohli, Daniel L. Thomas   +5 more
openaire   +1 more source

Calibration and Scale Performance of Bushland Weighing Lysimeters

Transactions of the ASAE, 1995
Weighing lysimetry is the primary method to directly measure evapotranspiration, and the scale performance of weighing lysimeters is often affected by wind loading. This study was conducted to calibrate the weighing lysimeters at Bushland, Texas, and to determine the effects of wind on the measurement accuracy of the lysimeter scales.
null T. A. Howell, null A. D. Schneider, null D. A. Dusek, null T. H. Marek, null J. L. Steiner   +4 more
openaire   +1 more source

CALIBRATION AND QUALITY CONTROL OF THE COSHOCTON WEIGHING LYSIMETERS

Transactions of the ASAE, 1999
Many weighing lysimeters, including the Coshocton lysimeters, use load cells to determine evapotranspiration (ET). Because measured ET is sometimes small (less than 0.5 mm for hourly ET), these instruments must be very accurate mass measurement devices. To achieve acceptable accuracy, weighing lysimeters require calibration.
Malone RW, Stewardson DJ, Bonta JV, Nelsen T   +3 more
openaire   +1 more source

Characterizing ground water use by safflower using weighing lysimeters

Agricultural Water Management, 2003
Abstract Decades of irrigation on the west side of the San Joaquin Valley without sufficient drainage have created large areas where shallow ground water (
R.W.O. Soppe, J.E. Ayars
openaire   +1 more source

WEIGHING LYSIMETERS FOR EVAPOTRANSPIRATION RESEARCH IN A HUMID ENVIRONMENT

Transactions of the ASABE, 2006
Three weighing lysimeters were developed for evapotranspiration research at the University of Florida, Institute of Food and Agricultural Sciences, Plant Science Research and Education Unit near Citra, Florida. The lysimeter design followed accepted procedures as well as aspects unique to the study site, including a foundation designed for a perched ...
Jia, Xinhua, Dukes, Michael D., Jacobs, Jennifer M., Irmak, Suat   +3 more
openaire   +2 more sources