This study aimed to evaluate the effects of salinity in the growth and nitrogen fixation in leucaena. Plants were cultivated in Leonard pots containing clean and sterilized sand. The treatments were distributed in a completely randomized design, in a 3x3 factorial, with five replicates. The first factor corresponded to no inoculation and inoculation with Bradyrhizobium sp SEMIA 6070 and SEMIA 6153 strains. The second factor corresponded to NaCl concentrations: 0, 25 and 50 mol m-3. Were analyzed the height and dry matter accumulation, the number of nodules and nitrogen in plants. The inoculation of plants with the strain SEMIA 6070 provided higher growth and greater nitrogen accumulation in plants thar were not subject to salinity. Nodulation was not affected by salinity. Inoculation with SEMIA 6153 strain provided greater tolerance to salinity.

This work had the objective of checking the echophysiological behavior of cowpea [Vigna unguiculata (L.) Walp.] cv. BRS Xique-xique cultivated under different levels of hydric deficit. The plants were cultivated in vases with capacity for 10L, containing one substratum composed by: 88,45% sand, 3,71% of clay, 7,84 % of silte. The experimental design was entirely randomized with three treatments (TO- reposition of 100% of lost water by evapotranspiration, T1- reposition of 50% and T2- reposition of 25%) and five repelicates. Previously, T1 and T2 suffered a period of stress and were later rehydrated. In the day of the assessment, the plants of T1 had been undergone to stress for three days, while the plants T2 for 5 days. The variables analyzed were: leaf water potential, net photosynthesis, stomatal conductance, transpiration, internal CO2 concentration and foliar temperature. The fewest availability of water caused reductions in the net photosynthesis rates, stomatal conductance and transpiration in T1 and T2 when they were compared to T0. The internal CO2 concentration in T2 was the greater among analyzed treatments. The reposition of 50 % of the lost water hasn´t caused any damage in the net photosynthesis.

The mobility and persistency of cadmium in the soil are determined by the intensity of adsorption by colloids. The evaluation of the free energy of cadmium adsorption by the soil is a measurement of the reaction strength. This study was carried out to evaluate the free energy of cadmium adsorption reaction in Luvisol and Cambisol samples after addition of different cadmium level. Cadmium adsorption was considered spontaneous, since free energy was negative. Free energy values decreased with increasing cadmium concentration and they were higher in samples with higher organic matter levels. Luvisol showed higher values of free energy of adsorption.