ABSTRACT.
Crop sequence to intensify forage production in one growing season

Marcos Figueroa R.1, Patricio Soto2 y Fernando Fernández E.3
 

Production throughout the year, under two forage crop sequences (oats-corn and ryegrass-corn), was studied at the Quilamapu Experimental Station (INlA), Ñuble (36°42 S lat. and 72°04W long). Winter,summer and total yields were measured. Winter production of strigosa oats and italian ryegrass were evaluated in a split-plot design, with 4 replications. Main treatments were species (oats and ryegrass), and subtreatments were N levels (0, 60, 120 and 180 kg/ha). In the second period, using corn, the residual effect of N applied on oat was evaluated, as well as the effect of the complementary N, applied on corn after ryegrass, up lo 180 kg N/ha; a randomized block design was used. Annual production of the two rotations were analized. Production of both species were similar (P > 0.05). Response of ryegrass to differents N levels can be defined by the funclion Y = 3.34 + 0.07X - 3.26 x 10-4X2 (r2 = 0.86). Residual effect on corn of the N applied in oats, can be represented by Y = 9.03 - 5.3 x 10-3 X + 1.63 x 10-4 X2 (r2 = 0.77). Yield was greatest when N was applied on corn after ryegrass, as shown by Y= 10.03 + 0.06X (r2 = 0.74). With the ryegrass-corn rotation, fertilized with 60 and 120 kg N/ha, the yleld measured was near 24.6 ton D.M./ha/year.

Keywords:
1 Facultad de Ciencias Agrarias y Forestales, Universidad de Concepción, Casilla 537, Chillán, Chile.
2 Estación Experimental Quilamapu (INIA), Casilla 426, Chillán, Chile.
3 Trabajo basado en la Tesis de Grado para optar al título de Ingeniero Agrónomo, en la Escuela de Agronomía, Universidad de Concepción, Chile.