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Composting was tried successfully with two organic residues, namely grape seed and olive mill wastes. The resulting compost was then applied to a clay soil and a sandy soil having 0.98 % and 0.6 % organic matter content respectively, each having poor structural stability and unsuitable water retention dynamics. The purpose of the work was to ameliorate fertility and structure by evaluating structural stability, infiltration rate, hydraulic conductivity and soil respiration after compost application. Laboratory trials were conducted by amending the two soils with different amounts of either compost from grape seeds (GS compost) or compost from olive mill residues (OM compost) to increase the organic matter to 1%, 1.5%, 2%, 2.5%, 3% and 15% and assess the most efficient treatment. After addition of compost, the aggregate stability under raindrop impact was increased notably in the two soils. Also, water retention was optimised, obtaining more water availability at high matrix potential values in the sandy soil and a more even distribution of water in the range wilting point-field capacity for the clay soil. The addition of compost produced a net increase in soil respiration which may favor better biological activity. The compost treatment proved to be efficient for ameliorating structure and fertility and produced useful orientations for field application.

The kinetics of proton adsorption (or desorption) at the surface of positively charged soil particles was investigated. Variations of pH as a function of the reaction time were analyzed by a first order kinetic equation. Specific rate coefficients at t= 0 were also calculated by drawing the tangents at the beginning of each reaction. Special attention was paid to the effect of both concentration and nature of the supporting electrolyte on the specific rate values in relation to the particular surface charge distribution of the examined soil.

Rock samples from the lithologic units forming the Adamello massif were analyzed for Rb and Sr concentrations and for87Sr/86Sr and18O/16O ratios. The most important features are as follows:(a)the strontium and oxygen isotopes show a systematic variation from south to northwest across the massif, the older units in the south being lower both in87Sr and18O;(b)a good positive correlation was found between strontium and oxygen isotopic compositions.