Phytoextraction may be applied at field scale when the removal of bioavailable metals is the specific target of the technology. Residual metals in soil can be considered substantially inert or to be evaluated by site specific risk analysis.

In PNAS, Sebilo et al. (1) present the fate of labeled nitrate in the soil–plant system over three decades and attempt to determine “to which extent and over which time periods fertilizer N stored in soil organic matter is rereleased for either uptake in crops or export into the hydrosphere.” I suspect that this mechanism of immobilization-mineralization turnover described by Sebilo et al. (1) ...

Soil alkalinisation generally constitutes a major threat to irrigated agriculture in the semiarid regions of West Africa. The improvement of sodic soils is generally difficult and expensive. However, a recent study in the Niger valley in NIGER, reveals that a natural dealkalinisation is possible under natural conditions in a semi-arid climate. Transformation of non-saline sodic soil into brown ...

The indigenous microflora of soil were released from the soil materials and concentrated without the occurrence of growth by use of a blending-simple centrifugation procedure. The cell concentrate was then frozen-etched and viewed by transmission electron microscopy. Criteria were established for detecting microbial cells among the residual soil debris. The freeze-etching of the soil cell conce...

•An improved YASSO model is proposed by considering residual spatial autocorrelation.•Model prediction errors are minimised using GIS data at the appropriate spatial scale.•Topographical factors describe 24-49% of variation in soil carbon.

Soil compaction was identified as the cause of ‘growth stunting disease’ in sultana grapes and ‘red death’ in cotton at the Lower Orange River and Vaalharts irrigation schemes. In an experiment growth stunting disease was eradicated completely and yields of sultanas increased substantially by deep cultivation, which eliminated compacted soil layers. Ripping increased the quality of tobacco, and...

In 1999, the Fall River Long-Term Site Productivity study began in coastal Washington to investigate how intensive management practices affect soil processes and forest productivity. By comparing conventional harvests to more intensive wood removal treatments, researchers are answering long-standing questions about how residual organic matter influences future growth. Also, by using herbicides ...

The removal of cadmium and turbidity from contaminated soil-washing water was studied by Electroflotation (EF) at the laboratory scale by using sodium lauryl sulfate (SLS) as an anionic surfactant, and calcium hydroxide (Ca(OH)2) as a coagulant. The stoichiometric cadmium to collector (SLS) and coagulant (Ca(OH)2) ratio was 1:4.5. Significant removal of cadmium (100 %, not detected in the resid...

Thirty-six fluoroaliphatic sulfones were tested to determine their residual toxicity to Solenopsis invicta Buren in soil. Six of the compounds gave >90% kill of the ants after they were exposed for 4 days at 10 ppm. When tested at 1.0 ppm, only one compound, AI3-10841, gave appreciable mortality. This compound was tested at 10 ppm in soil held outdoors under ambient summer conditions. Mortality...

Closing the energy budget at flux measurement sites is problematic, even when the fetch extends over flat, homogeneous surfaces with low vegetation cover. We used the residual energy balance and ordinary least square (OLS) linear regression methods to quantify spatial variability in soil heat flux contributing to energy balance closure (EBC), by deploying a mobile energy system within the footp...