Development of Strip Tillage on Sprinkler Irrigated Sugarbeet

Abstract

A project to evaluate new technologies for strip tillage of small seeded crops was initiated in fall 2003 near Sidney, Montana, for sprinkler irrigated sugarbeet (Beta vulgaris L.) to be grown in 2004. Strip till treatments were compared to conventional grower tillage practices in fifty-six 15- 25-m (48- 80-ft) side-by-side plots. Both treatments were flat planted with no ridges or beds. All strip tillage and fertilization was done in the fall after removal of a malt barley crop. Conventional tillage was done in the fall at the Sidney site and in the spring at the Nesson site. Thirty-centimeter (12-in.) wide strips were tilled directly into the straw residues about 20 cm (8 in.) deep using straight and paired fluted coulters and a modified parabolic ripping shank followed by a crows-foot packer wheel. Toothed-wheel row cleaners were installed in front of the straight coulter to move loose residue to the side to avoid plugging. At the same time, dry fertilizer was shanked (banded) about 8 to 13 cm (3 to 5 in.) below the anticipated seed placement location. Sugarbeet were planted about 2.5 cm (1 in.) deep with 60-cm (24-in.) spacing between rows in the spring. Toothed-wheel row cleaners were also placed in front of each row on the planter to move any residue displaced by winter storms. Operation of the strip tillage machine required about 25 tractor horsepower per row, but substantial fuel savings were realized with this system by reducing the number of tractor equipment field passes by up to 75%. In 2004, 2006, 2007, and 2008 there were no significant differences in yields or sugar production between the two tillage treatments; however, in 2005 the strip tilled plots produced about 17% greater yields (tonnage and gross sugar). This benefit in 2005 was primarily due to the standing straw stubble in the strip tilled plots that protected sugarbeet seedlings from blowing soil during a spring wind storm that severely damaged seedlings in the conventionally tilled plots where there was no surface crop residue. It was concluded that strip tillage must be considered as part of a larger cropping system that affects timing and equipment choices for planting, cultivation, spraying, and harvesting as well as tillage and other cultural practices. Based on these results, it is generally recommended that strip tillage should be performed in the fall on clay soils in eastern Montana where it has been shown to result in better seedbed conditions than spring strip tillage. Whereas lighter, sandy soils would probably produce equally well when strip tilled in the spring, which could then be combined with planting into a single pass tillage, fertilizing, and planting operation. Banding fertilizer is highly recommended under strip till to increase fertilizer use efficiencies and reduce input costs. RTK-GPS guided steering in combination with some type of mechanical steering assistance on the implements are also recommended for both strip tilling, planting, and cultivation (if needed).