2 results

Ion mobility in acid soils with surface application of lime, organic acid and crop residues

Milton Ferreira Moraes, Heitor Cantarella, José Antonio Quaggio, Aline Reneé Coscione

01/Aug/2007

The efficiency of subsurface acidity alleviation by surface liming in the presence of crop residues is controversial and more information is needed. The objective of this study was to quantify the contribution of cover crop residues, regarding their contents of low molar mass organic acids and soluble nutrients to mobilization in the soil profile of the reaction products of surface-applied lime. Two experiments were carried out under laboratory conditions using 30 cm high PVC cylinders filled with acid and clayey […]

Activity and chemical speciation of soil solution of an oxisol under no-tillage with different acidity conditions as affected by phosphorus addition

Antonio Nolla, Ibanor Anghinoni

01/Dec/2006

In no-tillage systems, crop residues and nutrients, namely phosphorus and calcium, accumulate in soil surface and can inactivate soil aluminum. In this way, only the presence of this element in soil analysis does not indicate plant toxicity, since organic and inorganic anions may affect the free aluminum dynamics by decreasing its activity in the soil solution. Knowledge on ion activity and speciation in soil solution is therefore useful to understand Al dynamics. Ionic activity and speciation were determined in the […]