Yield, quality and cost effectiveness of using fertilizer and/or alfalfa to improve meadow bromegrass pastures

Abstract

A 4-yr study was conducted to determine the effects of forage type and fertilization on yield and quality of dryland pastures on the Canadian prairies. Pastures contained either meadow bromegrass (Bromus biebersteinii Roem & Schult.) (G) or alfalfa (Medicago sativa L.)-meadow bromegrass (A) and were either unfertilized (U) or fertilized (F) in order to increase the availability of essential plant nutrients to recommended levels. Average pasture yields (1995-1998) of AF, AU, GF and GU treatments were 3.88, 3.12, 3.95 and 1.94 ± 0.19 t DM ha-1 and average carrying capacities were 200.4, 163.9, 208.7 and 127.6 ± 3.3 cow-days ha-1, respectively. Alfalfa content declined (P < 0.05) over the 4 yr from 75.4 and 84.1% in 1995 to 32.5 and 40.3% in 1998 for AF and AU pastures, respectively. Simple incorporation of alfalfa into grass pastures (AU) improved carrying capacity by 28% and met the nutritional requirements of lactating beef cows at no additional cost. Fertilization of meadow bromegrass pastures (GF) improved the carrying capacity by 64% and met the nutrient requirements of lactating beef cows. Incorporating alfalfa with fertilization (AF) improved carrying capacity of pasture by 57% and met the nutrient requirements of lactating beef cows. Both the AF and GF treatments entailed significant financial risk as they were only cost-effective strategies when precipitation was not limiting. The AU treatment did not entail financial risk and was always a cost-effective treatment.