Alfalfa (Medicago sativa L.) improvement with fertilization in different soil conditions

Patricio Soto O.1, Ernesto Jahn B. , Isaac Maldonado I . y Nicasio Rodríguez S.

Alfalfa pasture productivity is affected by the water table depth (WTD) in which it is established. In an alfalfa field three sites were selected that represented different WTD conditions: deep (NFP), intermediate (NFI) and superficial (NFS). A complete randomized block design experiment was established to study the response to different fertilizer applications (N, P, K, S, Ca, Mg) during two seasons. The objective was to determine the effect of the different fertilization treatments on dry matter production under different WTD. Parameters evaluated were: variations in WTD, soil moisture, DM production, and soil contents of N, P and K. With deep (D) condition WTD was 30 and 40 cm deeper than for Intermediate (I) and Superficial (S), respectively, during the winter period. Dry matter production of alfalfa increased (P<0.05) with complete fertilization; the average effect for the two seasons was 31; 183 and 177% for D, I and S soil conditions, respectively. The addition of N to the complete fertilization had a significant (P<0.05) effect on dry matter production only on the first season. For D application of N with the complete fertilization had no effect on production. Application of P increased content of P. Content of K in the soil decreased only for D.

Keywords: alfalfa yield, drainage, N, P, K.
1 Instituto de Investigaciones Agropecuarias. Centro Regional de Investigación Quilamapu, Casilla 426, Chillán, Chile. E-mail: psoto@inia.cl.