Response to phosphorus during the establishment of Lotus corniculatus L. in the Andeans foothills

Hernán Acuña P.1

Using a 4 x 2 factorial in a randomized blocks design, the effect on the establishment of Lotus corniculatus of four P levels, 0; 32.7; 65.5; and 131 kg/ha (0, 75, 150, and 300 kg of P2O5/ha), applied at planting, with and without N (32 kg/ha) was studied. The planting was in Unes, spaced 20 cm, on October 1981 and the seeding rate was 12 kg/ha of seed inoculated with the specific Rhizobium. A basic ferti)jzation with potassium and sulphur was used. Plant population was measured,two andtive months after planting; and cuttings tordry matter (D.M.) determination were done until November 1983. No significant differences (P > 0.05) were observed in population (approximately 70 plants/m2 in March 1982). The first season (September 1982 te April 1983) DM. increased significantly (P < 0.01) in a lineal fashion between 0 and 300 kg of P2O5/ha (0 and 131 kg of P/ha) and a detrimental effect of N was observed (2.6 to 8.3 ton D.M./ha, without N, and 1 .6 te 5.1, with N). In the November 1983 cutting, the treatments without P improved their yields, in comparison with the same cutting the previous year, and the positive response te P was maintained only when N was not applied.

1 Estación Experimental Quilamapu (INIA), Casilla 426, Chillán, Chile.