Effect of P Fertilization on Alfalfa Production, Winter Survival, and P Balances when Grown Alone or in Combination with Russian Wildrye in a Semiarid Environment.
(S04-selles573583-oral)
Authors:
F. Selles* - Agriculture Canada, Semiarid Prairie Agricultural Research Centre P.G. Jefferson - Agriculture Canada, Semiarid Prairie Agricultural Research Centre S.V. Angadi - Agriculture Canada, Semiarid Prairie Agricultural Research Centre
Abstract:
A field experiment designed to determine the effect of P fertilization on the survival of alfalfa seeded in pure stands or mixed with Russian Wildrye was started in 1997 on a Swinton Silt Loam (Aridic Haploboroll) in southwestern Saskatchewan, Canada. Phosphorus as triple superphosphate was applied either prior to seeding at rates of 20, 40 or 80 or as annual band applications of 10, 20 or 40 kg P2O5/ha. The A40 treatment was the only fertilizer regime that consistently produced the highest forage yields and forage P concentration. The P40 and P80 treatments were equal to A40 in the first two years of the study. All P treatments increased forage P concentration, especially A40 that consistently produced the highest P concentration. In the last year, however the preplant treatments failed to increase P concentration. Cumulative P balances for the check and preplant treatments had identical negative slopes and intercepts proportional to the rate of P applied. Balances for the annual treatments had intercepts proportional to applied P; while the A10 treatment had a zero slope, A20 and A40 had positive slopes proportional to the application of P. The level of Olsen P in the soil followed a trend similar to that described for the balance, and was proportional to the it, increasing by 0.61 mg/kg with an increase of 1 kg in the P balance (R2=0.70).
Speaker Information: Fernando Selles, Agriculture Canada, Semiarid Prairie Agricultural, P.O. Box 1030, Swift Current, SK S9H 3X2; Phone: (306) 778-7245; E-mail: [email protected]
Session Information: Tuesday, November 4, 2003, 2:55 PM-5:30 PM Presentation Start: 3:15 PM
Keywords: Phosphorus availability; Hay production; phosphorus uptake; Alfalfa winter kill