Furrow Traffic and Ripping for Control of Irrigation Intake

Abstract

Graded furrow applications of 100 to 200 mm (4 to 8 in.), which often exceed profile storage capacity, are common in the Southern High Plains for the first irrigation after primary tillage. This study evaluated furrow compaction by wheel traffic as a potentially low cost method of reducing excessive intake and conserving irrigation water. A two-year field study was conducted with irrigated grain sorghum on a slowly permeable Pullman clay loam (Torrertic Paleustoll). The objective was to determine the effects of furrow compaction by controlled wheel traffic on irrigation intake during the preplant irrigation following primary tillage. In addition, the effects of furrow ripping, before the second irrigation, were compared with the non-traffic control furrows as a means of restoring normal late-season intake. On relatively wide 1.5 m (5 ft) spaced furrows with a 0.15% slope, one traffic pass with a 6000 kg (13,200 lb) tractor increased average bulk density from 1.1 to 1.27 Mg/m3 at the 50 mm (2 in.) depth. Furrow traffic reduced irrigation water advance time up to 45% to reach 400 m (1320 ft), and reduced total intake by about 17% during the first irrigation after tillage. Ripping traffic furrows before the second irrigation increased growing season irrigation intake by 10% compared with the non-traffic furrows. Controlled furrow traffic reduced average growing season irrigation water intake by 12%. Furrow traffic and furrow ripping treatments did not significantly affect grain sorghum yield.