scholarly journals Evaluation of a Ground Penetrating Radar to Map the Root Architecture of HLB-infected Citrus Trees

Agronomy ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 354 ◽  
Author(s):  
Zhang ◽  
Derival ◽  
Albrecht ◽  
Ampatzidis
Keyword(s):  
Ground Penetrating Radar ◽  
Crop Production ◽  
Field Experiments ◽  
Structural Characteristics ◽  
Root Diameter ◽  
Moisture Level ◽  
Limiting Factors ◽  
Horizontal Distance ◽  
Tree Root System ◽  
Ground Penetrating

This paper investigates the influences of several limiting factors on the performance of ground penetrating radar (GPR) in accurately detecting huanglongbing (HLB)-infected citrus roots and determining their main structural characteristics. First, single-factor experiments were conducted to evaluate GPR performance. The factors that were evaluated were (i) root diameter; (ii) root moisture level; (iii) root depth; (iv) root spacing; (v) survey angle; and, (vi) soil moisture level. Second, two multi-factor field experiments were conducted to evaluate the performance of the GPR in complex orchard environments. The GPR generated a hyperbola in the radar profile upon root detection; the diameter of the root was successfully determined according to the width of the hyperbola when the roots were larger than 6 mm in diameter. The GPR also distinguished live from dead roots, a capability that is indispensable for studying the effects of soil-borne and other diseases on the citrus tree root system. The GPR can distinguish the roots only if their horizontal distance is greater than 10 cm and their vertical distance is greater than 5 cm if two or more roots are in proximity. GPR technology can be applied to determine the efficacy of advanced crop production strategies, especially under the pressures of disease and environmental stresses.

Modeling tree root diameter and biomass by ground-penetrating radar

2010 ◽  
Vol 54 (5) ◽  
pp. 711-719 ◽  
Author(s):  
XiHong Cui ◽  
Jin Chen ◽  
JinSong Shen ◽  
Xin Cao ◽  
XueHong Chen ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Root Diameter ◽  
Ground Penetrating

Ground-penetrating radar estimates of tree root diameter and distribution under field conditions

Trees ◽  
2018 ◽  
Vol 32 (6) ◽  
pp. 1657-1668 ◽  
Author(s):  
Keitaro Yamase ◽  
Toko Tanikawa ◽  
Masako Dannoura ◽  
Mizue Ohashi ◽  
Chikage Todo ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Root Diameter ◽  
Field Conditions ◽  
Ground Penetrating

scholarly journals Influences of water deficiency on the productivity of young plants at different sites

2018 ◽  
pp. 371-378
Author(s):  
Katalin Sárdi
Keyword(s):  
Crop Production ◽  
Production Efficiency ◽  
Field Experiments ◽  
Nutrient Supply ◽  
Limiting Factors ◽  
Nutrient Concentrations ◽  
Growth Stages ◽  
Water Deficiency ◽  
Negative Effects ◽  
Site Characteristics

Water deficiency has become one of the most limiting factors of crop production in Hungary as the tendency in annual amounts of precipitation shows a decreasing tendency; therefore, it has become similar to those of Southern Europe. The most significant decrease in precipitation occurs typically during spring, approximately 20% of the data expressed in the averages of the last century. Studying the relationship between water deficiency as a stress factor and nutrient supply is important in order to improve the production efficiency of crops. Nowadays, this problem receives outstanding attention presented in numerous papers both in Hungary and globally, however, there are several questions yet to be answered. Our pot experiments were carried out under controlled greenhouse conditions in order to establish new data on these relationships. Experimental soils were typical for Western Transdanubia, taken from long-term field experiments representing four different site characteristics of the region. It was concluded from the results that drought periods during the early growth stages (i.e. 4–5 weeks after emergence) of plants may result in significant decreases in both dry matter production, nutrient concentrations, nutrient uptake and shoot:root ratios. Better nutrient supply, especially potassium, plays a significant role in reducing the negative effects of water deficiency.

scholarly journals Ground-penetrating-radar response to fracture-fluid salinity: Why lower frequencies are favorable for resolving salinity changes

Geophysics ◽  
2008 ◽  
Vol 73 (5) ◽  
pp. J25-J30 ◽  
Author(s):  
Georgios P. Tsoflias ◽  
Matthew W. Becker
Keyword(s):  
Electrical Conductivity ◽  
Ground Penetrating Radar ◽  
Field Experiments ◽  
Fractured Rock ◽  
Low Frequency ◽  
Signal Amplitude ◽  
Time Lapse ◽  
Fracture Aperture ◽  
Fracture Fluid ◽  
Ground Penetrating

Time-lapse ground-penetrating-radar (GPR) surveys exploit signal-amplitude changes to monitor saline tracers in fractures and to identify groundwater flow paths. However, the relationships between GPR signal amplitude, phase, and frequency with fracture aperture and fluid electrical conductivity are not well understood. We used analytical modeling, numerical simulations, and field experiments of multifrequency GPR to investigate these relationships for a millimeter-scale-aperture fracture saturated with water of varying salinity. We found that the response of lower-frequency radar signals detects changes in fluid salinity better than the response of higher-frequency signals. Increasing fluid electrical conductivity decreases low-frequency GPR signal wavelength, which improves its thin-layer resolution capability. We concluded that lower signal frequencies, such as [Formula: see text], and saline tracers of up to [Formula: see text] conductivity are preferable when using GPR to monitor flow in fractured rock. Furthermore, we found that GPR amplitude and phase responses are detectable in the field and predictable by EM theory and modeling; therefore, they can be related to fracture aperture and fluid salinity for hydrologic investigations of fractured-rock flow and transport properties.

Limiting factors in the detection of tree roots using ground-penetrating radar

2008 ◽  
Vol 319 (1-2) ◽  
pp. 15-24 ◽  
Author(s):  
Yasuhiro Hirano ◽  
Masako Dannoura ◽  
Kenji Aono ◽  
Tetsurou Igarashi ◽  
Masahiro Ishii ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Limiting Factors ◽  
Tree Roots ◽  
Ground Penetrating

Detecting stemflow-induced preferential flow pathways through time-lapse ground-penetrating radar surveys

2021 ◽  
Author(s):  
Ludmila Roder ◽  
Simone Di Prima ◽  
Sergio Campus ◽  
Filippo Giadrossich ◽  
Ryan D. Stewart ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Preferential Flow ◽  
Overland Flow ◽  
Root Systems ◽  
Time Lapse ◽  
Water Infiltration ◽  
Blue Dye ◽  
Horizontal Distance ◽  
Tree Trunk ◽  
Ground Penetrating

<p>Research over the past several decades has shown that preferential flow is more the rule than the exception. However, our collective understanding of preferential flow processes has been limited by a lack of suitable methods to detect and visualize the initiation and evolution of non-uniform wetting at high spatial and temporal resolutions, particularly in real-world settings. In this study, we investigate water infiltration initiation by tree trunk and root systems. We carried out time-lapse ground penetrating radar (GPR) surveys in conjunction with a simulated stemflow event to provide evidence of root-induced preferential flow and generate a three-dimensional representation of the wetted zone.</p><p>We established a survey grid (3.5 m × 5 m, with a local slope of 10.3°), consisting of ten horizontal and thirteen vertical parallel survey lines with 0.5 m intervals between them. The horizontal lines were downslope-oriented. The grid was placed around a Quercus suber L. We collected a total of 46 (2 GPR surveys × 23 survey lines) radargrams using an IDS (Ingegneria Dei Sistemi S.p.A.) Ris Hi Mod v. 1.0 system with a 900-MHz antenna mounted on a GPR cart. Two grid GPR surveys were carried out before and after the artificial stemflow experiment. In the experiment, we applied 100 L of brilliant blue dye (E133) solution on the tree trunk. The stemflow volume of 100 L corresponded to 63.2 mm of incident precipitation, considering a crown projected area of 201 m<sup>2</sup> and a 1.3% conversion rate of rainfall to stemflow. Trench profiles were carefully excavated with hand tools to remove soil and detect both root location and size and areas of infiltration and preferential pathways on the soil profile.</p><p>The majority (84.4%) of artificially applied stemflow infiltrated into the soil, while the remaining 15.6% generated overland flow, which was collected by a small v-shaped plastic channel placed into a groove previously scraped on the downhill side of the tree. The 3D diagram clearly demarcated the dimension and shape of the wetted zone, thus providing evidence of root-induced preferential flow along coarse roots. The wetted zone extended downslope up to a horizontal distance of 3 m from the trunk and down to a depth of approximately 0.7 m. Put all together, this study shows the importance of accounting for plant and trees trunk and root systems when quantifying infiltration.</p>

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