Rj. Campo et Af. Lantmann, EFFECTS OF MICRONUTRIENTS ON BIOLOGICAL NITROGEN-FIXATION AND SOYBEANPRODUCTIVITY, Pesquisa agropecuaria brasileira (1977), 33(8), 1998, pp. 1245-1253
The effects of micronutrients on biological nitrogen fixation (BNF) an
d on soyabean yield were studied in two sets of field experiments. The
effects of Zn, Co, B and Mo were tested at three sites (soils LRe, LE
a and, LRd) where soyabean had been cultivated for more than eight yea
rs. In the other set, the effects of Mo (9.0 g) were tested at two sit
es of acid soils (LBd and LRa), in a first-year soyabean crop producti
on, at different levels of lime. The micronutrients were applied on th
e seeds,just before inoculation with Bradyrhizobium elkanii, using 80
kg of seeds by hectare: 15 g of Zn, 0.75 g of Co, 4.5 and 9.0 g of Mo
and 3.0 g of B. In soils already cultivated with soyabean, Zn, Co and
B did not increase BNF and soyabean yield, but Mo increased BNF and so
yabean yield in two of these soils. Mo did not increase BNF and soyabe
an yield in LBd soil. In the other soil (LRa soil), Mo increased BNF a
nd soyabean yield, but only without lime.