This study investigates the use of photoacoustic spectroscopy (PAS) for rapid soil analysis. Photoacoustic spectroscopy requires very minimal sample preparation (air-drying), which is a major advantage compared to the more traditional transmittance technique, which requires time-consuming preparation of pellets. The amount of information contained in the PAS spectra appears to be similar to tha...

the prevalent method of irrigation in paddy fields in iran is continuous ponding, which changes to intermittent method at the time of water shortage. soil cracks are the main problem in intermittent irrigation. in this study, effects of adding rice straw on some soil physical characteristics and cracks were studied in paddy soils of the guilan province of iran. the experiment was performed as s...

A survey was conducted over a 22-year period to evaluate the influence of soil texture and land use on the geographical distributions of Rotylenchulus reniformis, Meloidogyne incognita, and Tylenchulus semipenetrans in the lower Rio Grande valley. The distributions of R. reniformis and M. incognita were related to soil texture, whereas T. semipenetrans occurred wherever host plants were present...

The adsorption potential of clay and sandy soil to remove benzene from liquid-phase system was examined. A series of batch adsorption tests were carried out for various concentrations of benzene (50 250 mg/l) in tightly corked 1000 ml flasks for clay and sandy soil, respectively. Equilibrium and kinetics data were obtained from the batch experiments. Adsorption increased with increasing initial...

An initial application of CPT results is to evaluate soil type and soil stratigraphy. One of the more common CPT-based methods to estimate soil type is the chart suggested by Robertson et al (1986) based on cone resistance, qc and friction ratio, Rf. Although newer charts have been developed based on normalized parameters, the simple chart based on qc and Rf is still popular because it is easy ...

Fluctuations in numbers of Rhizobium leguminosarum biovar trifolii and its bacteriophages in two fields with different soil types were followed during a 17-month period in 1981 and 1982. Mean levels of both phage and rhizobia varied significantly (P < 0.05) on different occasions, with rhizobial levels varying from 1.6 x 10 to 2.0 x 10 cell per g of soil and phage from 0 to 1.7 x 10 PFU/g of so...

Woody plant expansion into grasslands and savannas is a global concern. Rapid expansion of Juniperus virginiana, a tree native to North America, has profound ecological consequences. We used transplanted J. virginiana seedlings to investigate the role of resource availability on J. virginiana expansion following the removal of fire, the factor historically limiting range expansion of this firei...

The mineralization of phenanthrene in pure cultures of a Pseudomonas fluorescens strain, isolated from soil, was measured in the presence of soil humic fractions and montmorillonite. Humic acid and clay, either separately or in combination, shortened the acclimation phase. A higher mineralization rate was measured in treatments with humic acid at 100 microg/ml. Humic acid at 10 microg/ml stimul...

Soil variability is a complex attribute that can affect geotechnical engineering design. This paper presents the initial stage of a study into the variability of soil proprieties at the Port of Navegantes, southern Brazil. This study is based on laboratory and field tests that were done as part of the Port enlargement planning. The database consisted of SPT, Vane, soil characterization, oedomet...

A new approach was developed for reducing leaching of herbicides and contamination of groundwater. Liposome-clay formulations of the anionic herbicides sulfometuron and sulfosulfuron were designed for slow release by incorporating the herbicide in positively charged vesicles of didodecyldimethylammonium (DDAB), which were adsorbed on the negatively charged clay, montmorillonite. Freeze fracture...