ChileanJAR

Red dover showed a response both to deficiency and excess of micronutrients. To study these two effects, dry matter production was measured when B, Cu, Mn, Mo and Zn was added to the PKCaMgS basic fertilization and when these micronutrients were not added. Increased productions with the complete formulation indicate a micronutrient deficiency and reduced productions with this same formulation indicate excess of one or more micronutrients. In 8 out of 19 soils a micronutrient deficiency was detected. In most cases, this deficiency occurs together with a macronutrient deficiency. Mo was deficient in 8 soils; B, in 5; and Zn, in 1 (or possibly 2). No deficiency in Mg or Cu was detected. Mo deficiency was observed independently of the other micronutrients; but B and Zn deficiency occurred always in addition to Mo deficiency. Nevertheless, the most intensive deficiency was observed in a soil (Puren) low in B. B showed a negative effect in 7 soils, Cu, in 6; Mg, in 5 ;and Zn, n 4. No negative effect was found with Mo. The technique by omision was effective to detect a deficiency of 2 ormoremicronutrients;in these cases, the technique by addition was not adequate. Nitrogen nutrition was provided by symbiotic fixation due to natural inoculum; no bacteria or N was added to the experimental material.