Identification of rooting depth and measurements of plant root activity in situ and in toto under field conditions using a gamma probe technique

1984 ◽  
Vol 40 (6) ◽  
pp. 585-587 ◽  
Author(s):  
K. P. R. Vittal ◽  
B. V. Subbiah
Keyword(s):  
Plant Root ◽  
Gamma Probe ◽  
Field Conditions ◽  
Root Activity ◽  
Rooting Depth ◽  
Probe Technique

Design of a gamma probe for root activity measurement in situ

1982 ◽  
Vol 33 (3) ◽  
pp. 197-201 ◽  
Author(s):  
K.P.R. Vittal ◽  
B.V. Subbiah ◽  
S.W. Kale
Keyword(s):  
Gamma Probe ◽  
Root Activity ◽  
Activity Measurement

scholarly journals Assessment of the Accuracy of a Multi-Beam LED Scanner Sensor for Measuring Olive Canopies

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4406 ◽  
Author(s):  
Rafael Sola-Guirado ◽  
Sergio Bayano-Tejero ◽  
Antonio Rodríguez-Lizana ◽  
Jesús Gil-Ribes ◽  
Antonio Miranda-Fuentes
Keyword(s):  
Laboratory Test ◽  
Real Time ◽  
Relative Error ◽  
Laser Scanner ◽  
Field Tests ◽  
High Accuracy ◽  
Field Conditions ◽  
Canopy Trees ◽  
Canopy Volume

Canopy characterization has become important when trying to optimize any kind of agricultural operation in high-growing crops, such as olive. Many sensors and techniques have reported satisfactory results in these approaches and in this work a 2D laser scanner was explored for measuring canopy trees in real-time conditions. The sensor was tested in both laboratory and field conditions to check its accuracy, its cone width, and its ability to characterize olive canopies in situ. The sensor was mounted on a mast and tested in laboratory conditions to check: (i) its accuracy at different measurement distances; (ii) its measurement cone width with different reflectivity targets; and (iii) the influence of the target’s density on its accuracy. The field tests involved both isolated and hedgerow orchards, in which the measurements were taken manually and with the sensor. The canopy volume was estimated with a methodology consisting of revolving or extruding the canopy contour. The sensor showed high accuracy in the laboratory test, except for the measurements performed at 1.0 m distance, with 60 mm error (6%). Otherwise, error remained below 20 mm (1% relative error). The cone width depended on the target reflectivity. The accuracy decreased with the target density.

scholarly journals Root capacitance measurements allow non-intrusive in-situ monitoring of the seasonal dynamics and drought response of root activity in two grassland species

2020 ◽  
Vol 449 (1-2) ◽  
pp. 423-437
Author(s):  
Imre Cseresnyés ◽  
Kálmán Rajkai ◽  
Katalin Szitár ◽  
László Radimszky ◽  
Gábor Ónodi ◽  
...  
Keyword(s):  
Seasonal Dynamics ◽  
In Situ Monitoring ◽  
Root Activity ◽  
Drought Response ◽  
Grassland Species ◽  
Capacitance Measurements ◽  
Root Capacitance

scholarly journals Application of a Monopole Antenna Probe with an Optimized Flange Diameter for TDR Soil Moisture Measurement

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2374
Author(s):  
Jacek Majcher ◽  
Marcin Kafarski ◽  
Andrzej Wilczek ◽  
Aleksandra Woszczyk ◽  
Agnieszka Szypłowska ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Root System ◽  
Plant Root ◽  
Time Domain Reflectometry ◽  
Monopole Antenna ◽  
Field Conditions ◽  
Growth Monitoring ◽  
Electromagnetic Simulations ◽  
The Time Domain ◽  
Plant Root System

Soil volumetric water content (θ) is a parameter describing one of the most important factors conditioning proper plant growth. Monitoring soil moisture is of particular importance in the rational use of water resources for irrigation, especially during periods of water scarcity. This paper presents a method of measuring soil moisture in the vicinity of the plant root system by means of a probe designed to be mounted on a mobile device used for precise plant irrigation. Due to the specific field conditions of the measurement, the design of the probe was proposed as a monopole antenna. Electromagnetic simulations of the probe were carried out with Ansys HFSS software to optimise its dimensions. Then a prototype of the probe was manufactured to conduct laboratory measurements with the use of a vector network analyser (VNA) working in the 20 kHz to 8 GHz frequency range. The VNA analyser was configured to work in the time-domain reflectometry (TDR) mode. From measurements of the time distance between reflections from the probe’s elements it is possible to calculate the bulk dielectric permittivity of the soil surrounding the probe. Next, based on commonly used soil moisture dielectric calibrations one can determine θ of the soil sample. The paper presents simulation results and laboratory tests of an antenna probe. Due to its tough and durable design, this type of probe gives the possibility of easy application in field conditions, which makes it especially suitable for mechanically demanding measurement systems. As the sensitivity zone is comparatively large, this probe is well-suited to measuring soil moisture in the vicinity of the plant root system.

An inexpensive portable freezer for in situ freezing in the field

2002 ◽  
Vol 32 (12) ◽  
pp. 2160-2168 ◽  
Author(s):  
Yves Dubuc ◽  
Jean Dubuc ◽  
Francine J Bigras
Keyword(s):  
Picea Glauca ◽  
White Spruce ◽  
Field Conditions ◽  
Natural Conditions ◽  
Dry Ice ◽  
Ambient Temperatures ◽  
Programmable Controller ◽  
Controlled Conditions ◽  
Large Trees

A portable freezer was developed to apply frost to branches of large trees to study their growth and recuperation after frost application under natural conditions. The freezer measures 37.5 × 63.5 × 31.5 cm and weighs approximately 3 kg. It consists of two compartments, a freezing compartment and a dry ice compartment. The portable freezer provides a ramp-and-soak freezing pattern using a programmable controller. The nonfreezing temperature plateaus can be set from 1 to 6°C and maintained for 0 to 12 h. The cooling and warming rates can be programmed from 1 to 12°C·h–1. Test temperatures can be maintained for a period of time ranging from 0 to 12 h at set temperatures. Freezers were tested without samples under controlled conditions at ambient temperatures of 0, –5, –10, 5, 15, 20, and 25°C. Under these conditions, the cooling and warming rates showed a deviation of less than ±1°C·h–1 at a set rate of 2°C·h–1. The freezer provides test temperatures as low as –38°C and –47°C at ambient temperatures of 20 and –10°C, respectively. Freezers were also tested under field conditions on attached branches in mature white spruce (Picea glauca (Moench) Voss) trees under hardening conditions.

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