559 Soil Sci. Soc. Am. J. 76:2012 Posted online 6 Feb. 2012 doi:10.2136/sssaj2011.0060 Received 16 Feb. 2011. *Corresponding author ([email protected]). © Soil Science Society of America, 5585 Guilford Rd., Madison WI 53711 USA All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recordi...

Phenomena occurring in soil pores can best be studied if the geometry of the pore space is understood. A number of models for the pore space have been proposed. These have included a Boolean grain process, fractals, packed sphere and other grain models, bubble processes, cracking processes and a range of models based on simple geometrical objects. This paper considers the issues raised by these...

Gas-particle flows are involved in various industrial applications in the energy, oil and gas fields, like coal gasification, production of light hydrocarbons by fluid catalytic cracking, catalytic combustion and different treatments aiming to reduce or eliminate pollutants. In addition, gas-particle flows take part to interesting natural phenomena, like volcanic eruptions, and their understand...

Yams (Dioscorea spp.) are food crops of growing significance in sub Saharan Africa. Unfortunately, nematodes are major pests to their production. A study was undertaken in major yam growing areas of Uganda to investigate the association of plant parasitic nematodes with damage symptoms. Nematodes were assessed from tubers, roots and surrounding soil for seven cultivars belonging to Dioscorea al...

Vertisols have unique morphology and the capacity to change volume with changes in water content; therefore, they are well known for their spatial and temporal variability. Our objectives were to address the spatial variability of Vertisol surface and subsurface features, as well as the spatial and temporal variability of Vertisol cracking. First, we discuss surface and subsurface features of V...

Seasonal cracking of the soil matrix results in poor estimates of runoff and infiltration by simulation models due to the changing soil storage conditions. In this study, soil surface elevation changes were measured every two weeks and soil crack volume was calculated for a two-year period at the USDA-Agricultural Research Service, Riesel Y-2 watershed in central Texas. Soil anchors were placed...

soil water content. Mackie-Dawson et al. (1989) studied the evolution of the cracking system in the first 10 cm Electrical resistivity measurements at high resolution (1.5-cm elecof soil by using vertical image analysis. They observed trode spacing) were performed to detect, from the soil surface, small cracks developing within the soil. We recorded a vertical electrical significant soil struct...

BACKGROUND Subsurface transport via tile drains can significantly contribute to pesticide contamination of surface waters. The spatial variation in subsurface leaching of normally applied herbicides was examined together with phosphorus losses in 24 experimental plots with water sampled flow-proportionally. The study site was a flat, tile-drained area with 60% marine clay in the topsoil in sout...