ChileanJAR

The pH of the rhizosphere of wheat (Triticum aestivum), variety Maitén-INIA, and lupine (Lupinus albus), growing in a phosphorus defficient Vilcun Soil (Typic Dystrandept) and kept in plexiglass boxes, were determined by infiltration of the soil with agar containing a pH indicator. Compared to the bulk soil (pH 5.9), the pH increased to more than 6.8 in the rhizosphere of wheat plants and decreased to less than 5.2 in the rhizosphere of lupine plants. These results contributes to explain the more efficient phosphate uptake by lupine compared with wheat, in phosphorus defficient soils, since acidification of the rhizosphere can increase the solubility of phosphate compounds in the soil.