Renovating Alfalfa Stands in Arizona

Abstract

Introduction: Alfalfa is an important crop grown in Arizona with approximately 250,000 acres in production in 2011 and 2012 and 260,000 acres for 2013 (USDA, NASS 2013). A typical yield for Arizona alfalfa growers is approximately 8.2 tons per acre (USDA, NASS). In central Arizona where fields are irrigated, harvest typically starts in March and lasts until November, with majority of production occurring from March to mid-July. Central Arizona producers will typically keep stands for three to four years before rotating. Older alfalfa stands age and thin and will eventually decline in plant density and yield (Figure 1). Producers often wish to improve their stands by reseeding after a failed seeding, thinning, or summer scalding.