Greater exploitation of subsoil resources by annual crops would afford multiple benefits, including greater water and N acquisition in most agroecosystems, and greater sequestration of atmospheric C. Constraints to root growth in the subsoil include soil acidity (an edaphic stress complex consisting of toxic levels of Al, inadequate levels of P and Ca, and often toxic levels of Mn), soil compac...

We provide a simple mathematical model of the bioremediation of contaminated wastewater leaching into the subsoil below a septic tank percolation system. The model comprises a description of the percolation system's flows, together with equations describing the growth of biomass and the uptake of an organic contaminant concentration. By first rendering the model dimensionless, it can be partial...

The Iowa soil-test interpretations and fertilizer recommendations for phosphorus (P) and potassium (K) were last updated in 1996 and 1999. The 1996 update involved the most important changes compared with previous recommendations. New soil-test P and K interpretation classes (very low, low, optimum, high, and very high) were developed to classify soil-test values into two sets corresponding to ...

Drinking-water quality in both urban and rural areas of Pakistan is not being managed properly. Results of various investigations provide evidence that most of the drinking-water supplies are faecally contaminated. At places groundwater quality is deteriorating due to the naturally occurring subsoil contaminants or to anthropogenic activities. The poor bacteriological quality of drinking-water ...

We assessed the impacts of hay-scented fern (Dennstaedtia punctilobula (Michx.) Moore) and subsoil liming (CaO amendments) on root and shoot growth of greenhouse-grown, first-year, northern red oak (Quercus rubra L.) seedlings. Red oak seedlings and ferns were grown in reconstructed soil profiles of four common Pennsylvanian forest soils. When grown in the presence of hay-scented ferns, with or...

Eastern gamagrass, Tripsacum dactyloides L., has been reported to tolerate a wide variety of soil conditions, including drought, flooding, and acidity, but its specific tolerance to aluminum (Al) has not been tested. One strain of this species, PMK Select Lot 94 SFG-1, was tested for its tolerance to excess Al in an acid, Al-toxic Tatum subsoil (clayey, mixed, thermic, Typic Hapludult) and in n...

The deposition of high levels of reactive nitrogen (N) and sulphur (S), or the legacy of that deposition, remain among the world's most important environmental problems. Although regional impacts of acid deposition in aquatic ecosystems have been well documented, quantitative evidence of wide-scale impacts on terrestrial ecosystems is not common. In this study we analysed surface and subsoil ch...

Ground Penetrating Radar (GPR) and airborne thermography have been used for the location of buried spring barrier ponds and for the investigation of the shallow subsoil. Thermography has been selected for its ability to cover a wide area in a short time, the GPR has been chosen for the ability to distinguish, in great detail the presence of permeable layers composing the subsoil. Very positive ...