VARIAÇÃO SAZONAL DE SULFATO, ENXOFRE TOTAL E MATÉRIA ORGÂNICA NO GÊNERO HUMIRIANTHERA, EM FUNÇÃO DA IDADE

Twenty eight (23) H. ampla and nine (09) H. rupestris adult and young specimens were collected to determine the levels of S0₄^~ and total-S in leaf, stem, tuber and in the soil where they grow. In H. ampla the level of S0₄^~ varied from 022.-078% and in H. rupestris from 0.22-138%. The level of S in H. ampla varied from 0.74-0.96% and In H. rupestris from 0.75-1.02%. The level of S0₄^~ IH H. ampla follows the pattern leaf>tuber>stem Independent of time of year and physiological age, while in H. rupestris the pattern is tuber>leaf>stem. The 5 shows a different behavior, maintaining the pattern tuber>stem>Jeaf for H. ampla and tuber>leaf>stem for H. rupestris. In the soil where H. ampla grows no variation in level of S0₄^~ (052%) was observed while for H. rupestris the variation was from 027-0.63% being higher in the rainy season. Due to the vegetation-soil interrelationship the levels of organic C, N, P, K, Ca, Mg, Na, Mn, Fe, Al and Zn were analyzed in the vegetative material and in the soil.