Wednesday, 8 October 2008: 2:45 PM
George R. Brown Convention Center, 361C
Reduced-tillage and high-efficiency irrigation systems reduce fuel and water inputs compared to conventional practices, but these alternative management systems have not been extensively evaluated in sugarbeet (Beta vulgaris L.)/malting barley (Hordeum vulgare L.) cropping systems. A field study comparing two sugarbeet tillage systems (conventional and strip-tillage) and two sprinkler irrigation nozzle designs (mid-elevation spray application, MESA; low-energy precision application, LEPA) was conducted near Sidney, MT. Strip tillage (ST) was performed (preceding sugarbeet only) using a single operation that left alternating 30-cm wide strips of tilled and untilled soil. Fertilizer was banded 10 deep cm during the tillage operation. Conventional tillage for sugarbeet consisted of six separate operations using different tillage implements performed following a broadcast application of fertilizer. Tillage preceding barley consisted of a single pass with a field cultivator following a broadcast application of fertilizer. Sugarbeet grown with ST yielded as well or better than when grown with conventional tillage (CT) in all four years. In two of four years, ST resulted in root sucrose content that was about 5 g kg-1 higher than with CT. Irrigation nozzle design did not affect sugarbeet yield. A significant tillage × irrigation interaction indicated that yield was higher with
than with LEPA under CT while there was no effect of irrigation type under ST management. Barley yield was not affected by irrigation nozzle design, but in three of four years was from 5 to 15% lower following ST sugarbeet than when following CT sugarbeet. It was concluded that sugarbeet yield with ST is equal to or better than with CT under sprinkler irrigation management using either MESA or LEPA nozzles. Barley was unaffected by irrigation nozzle type but yielded an average of 6% less following ST-sugarbeet than following CT-sugarbeet.