High aluminum concentrations decrease the nodulation potential, hence the biological atmosferic nitrogen fixation of legume. This greenhouse experiment was aimed to evaluate the effects of limestone applyet on alfalfa cultivation in alic YELLOWISH RED LATOSOL SOIL, clay texture. It evaluated the ideal Ca2+ and Mg2+ ratios in neutralizing soil acidity. Treatments were two alfalfa cultivars (Florida 77 and Creoula), four limestone rates (1.2; 2.4; 4.8; 7.2t.ha-1) and five stoichiometric percentual ratios Ca:Mg between (100:0; 75:25; 50:50; 25:75; 0:100), in a factorial set up into a completely randomized design with four replications. Nodulation and nitrogen contents in the shoots increased with increased limestone rates. Shoots dry matter production of both cultivars increased with the rates of limestone, but only the cultivar Florida 77 showed significant differences among Ca:Mg ratios.
Medicago sativa; nodulation efficiency; liming
