Surface soil-pH map of Queensland

Abstract

Surface soil pH can influence biological activity, nutrition and various chemical processes in the soil. Low pH or acidity is causing major concern in southern Australia, prompting requests for details on the extent, severity and distribution of acidic soils in Queensland. By creating a soil pH database, using an appropriate base map, rainfall isohyets and GIS technology, a coloured pH map of surface soils was produced at a 1:5000000 scale for the entire State. As most samples were from virgin or little disturbed sites, the map generally reflects naturally occurring soil pH. Developed horticultural, agricultural and fertilized pastoral areas are likely to have lower pH than that mapped. About two thirds (63.1%) of Queensland's soils have acidic surfaces, 9.5% neutral and the remaining 26.9% are alkaline. The major proportion (74%) of the > 1200 mm rainfall zone is strongly acid, and the remainder is medium acid or acid. Much of the sugar growing areas occur in this zone. Surface soil pH generally decreases as rainfall increases and to a lesser extent from subtropical to tropical climate. In addition to climate, identification of the soil type assists with predicting pH, as the organic, coarse and medium textured soils and massive earths are more likely to be acid and have low buffering capacity. Depending on the land use, such soils may require regular liming or minimizing of net acidifying practices for long term sustainability.

Increased diversification rates are coupled with higher rates of climate space exploration in Australian Acacia (Caesalpinioideae)

“…Within ES 1, rhizosphere adaptations may be a key trait to cope with the annual extremes of cyclically waterlogged and parched tropical monsoon soils (Bui et al , ). Soil pH tends to decrease with rainfall: tropical monsoon soils tend to be acidic, whereas those to the south are often more alkaline (Ahren et al , ; Henderson et al , ). The concentration of tropical monsoon species into a few diverse clades (Fig.…”

Australia-wide predictions of soil properties using decision trees

“…6. Compared to a map generated by linking a chloropleth map to a soil database such as the one presented in Ahern et al (1994) for surface pH in Queensland, the ASRIS map clearly represents much more local variability. The digital maps for all soil property predictions are available at http://audit.ea.…”

Molecular Characterization of Indigenous Rhizobia from Kenyan Soils Nodulating with Common Beans

“…The soil pH at the two experimental sites was 5.20 in Kakamega and 6.08 in Busia and, therefore, officially characterized as acidic (less than 6.5) [35]. The exchangeable amounts of Al, Mn, and Cu were 1.72 Cmol/kg, 63.1 ppm, and 2.3 ppm in Kakamega and 0.95 Cmol/kg, 35.1 ppm, and 1.60 ppm in Busia soils, respectively.…”