X-ray microcomputed tomography (μCT) is an invaluable tool for visualizing plant root systems within their natural soil environment noninvasively. However, variations in the x-ray attenuation values of root material and the overlap in attenuation values between roots and soil caused by water and organic materials represent major challenges to data recovery. We report the development of automati...

Many applications for irrigation management and environment monitoring exploit buried sensors wired-connected to the soil surface for information retrieval. Wireless Underground Sensor Networks (WUSNs) is an emerging area of research that promises to provide communication capabilities to these sensors. To accomplish this, a reliable wireless underground communication channel is necessary, allow...

Sulfonamide antibiotics are a commonly used group of compounds in animal husbandry. They are excreted with manure, which is collected in a storage lagoon in certain types of confined animal feeding operations. Flood irrigation of forage fields with this liquid manure creates the potential risk of groundwater contamination in areas with shallow groundwater levels. We tested the hypothesis that-i...

Unlike terrestrial Wireless Sensor Networks (WSNs), communication between buried nodes in WUSNs happens through the ground. Due to the complexity of soil, accurate estimation of the underground signal attenuation is challenging. Existing path loss models mainly rely on semi-empirical and empirical mixing models for calculating the dielectric properties of the soil. In this paper, two existing m...

A diesel fuel spill was simulated on a 12-m(2) plot of agricultural land, at a concentration of 1 Lm(-2) of soil. The natural attenuation of Volatile Aromatic Hydrocarbons (VAHs) was monitored at different soil depths over a period of 50 days. The natural attenuation of VAHs in the surface layer would be attributed to two processes, namely: volatilisation (mainly linked to the boiling point of ...

In 1992 a new method of soil particle-size analysis was introduced, which coupled sedimentation to gamma-ray attenuation. The theoretical possibility of an alternative for this method is here presented, which includes the necessity of sieving soil samples, but simpli®es the gamma-ray measurements. Advantages and disadvantages of this alternative are discussed. # 1999 Elsevier Science B.V. All r...

2,4,6-Trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (Royal Demolition Explosive, or RDX) deposited on hand grenade training ranges can leach through the soil and impact shallow groundwater. A 27-mo field monitoring project was conducted to evaluate the transport and attenuation of high explosives in variably saturated soils at an active grenade range located at Fort Bragg, N...

The objective of this paper is threefold: 1) To present a working methodology for the combined use of modeling technology and microwave remote sensing measurements in the assessment of attenuation of electromagnetic waves by the vegetation cover; 2) To illustrate this methodology with computer calculations of the attenuation for various soil-plant formations; 3) To give a perspective of the dev...

Although macropore flow is recognized as an important process for the transport of pesticides through a wide range of soils, none of the existing spatially distributed methods for assessing the risk of pesticide leaching to groundwater account for this phenomenon. The present paper presents a spatially distributed modelling system for predicting pesticide losses to groundwater through micro- an...