Effects of P and Mo applications on acid Andisol and Red Clover, Ribera et al. PHOSPHORUS-MOLYBDENUM RELATIONSHIP IN SOIL AND RED CLOVER (Trifolium pratense L.) ON AN ACID ANDISOL

We studied the phosphorous (P) and molybdenum (Mo) relationship in soil and red clover (Trifolium pratense L.) in a non limed and limed acid Andisol of Southern Chile. In soil, we evaluated the effect of different liming (0 and 2000 mg kg-1), P (0, 200 and 400 mg kg-1), and Mo (0, 0.58 and 0.96 mg kg-1) doses supply on soil available Mo. In addition, the availability of P and Calcium (Ca) in treated soils was determinated. In red clover, we studied the Mo and P shoot concentrations and dry matter yield in response to the different treatments applied to the soil. Also, we measured the changes produced by Mo uptake in shoot Cu concentrations. The results showed that both, lime and more strongly P and Mo additions significantly (P < 0.05) increased soil Mo availability. In contrast, soil available P was not significantly (P < 0.05) affected by liming and Mo treatments. A significant high correlation (r = 0.579, at P < 0.05) was observed among soil Mo availability and shoot Mo concentrations, as well as between soil available P and shoot concentration of P (r = 0.844, at P < 0.01). In this study for all fertilization treatments, shoot Cu concentrations reached values which are considered as normal fo