Solid phase microextraction (SPME) coupled with gas chromatography was employed to estimate bioavailability of pyrene in soils with different properties of textures, organic matter contents (SOM) and aging periods. Experimental results indicated that biodegradation rates increased from 0.10 (sandy loam) to 0.15 (silty loam) microg g-1 hr1. By contrast, biodegradation rate decreased from 0.10(1....

Quantitative growth response of watermelon (Citrullus lanatus) sensitive to Meloidogyne incognita is poorly understood. Determination of soil population densities of second-stage juveniles (J2) of M. incognita with Baermann funnel extraction often is inaccurate at low soil temperatures. In greenhouse experiments, three sandy soils were inoculated with dilution series of population densities of ...

The incorporation of biochar into soils has been proposed as a means to sequester carbon from the atmosphere. An added environmental benefit is that biochar has been shown to increase soil retention of agrochemicals, and recent research has indicated that biochar may be effective in increasing soil retention of bacteria. In this study we investigate the transport behavior of Escherichia coli O1...

Most of the Tylenchulus semipenetrans larvae applied on the surface of four soils in pots 14.5-cm deep moved no further downward than 6.5 crn, and remained in the upper half of the pot. The percentage of second-stage larvae that developed into adult females on 'Homosassa' sweet orange in the soils were: sandy loam, 6.8% in the same soil with inoculation holes, 8.6%; loamy sand, 5.4%; coarse san...

Two soils spiked with lead at different rates were stabilised/solidified using Portland cement and fly ash at different soil:binder ratios and tested for their setting time, unconfined compressive strength (UCS), leachability and durability. Results show that soil texture, percentage of binders and lead concentration play an important part in the treatment, significantly influencing the perform...

Some of these soil orders such as Ultisols and Oxisol account for 34% of the area of major soil orders in the tropics. These orders occupy great amounts of land (approximately 1,666 million hectares) in Africa and South and Central America (Fig. 2). Histosols and sandy Entisols also contain low levels of Si (57). As a result of Si leaching, the soluble Si content of tropical soils, such as Ulti...

in-situ testing techniques have proven to be successful in improving the speed and reliability of geotechnical investigations. one of the most common in-situ methods in engineering geology and site investigation is cone penetration test (cpt), which is mainly used for characterization of soils, as it is a robust, simple, fast, reliable and economic test that can provide continuous soundings of ...