Effect of Three Tillage Depths on Sugarbeet Response and Soil Penetrability Resistance

Abstract

Tillage can alter soil properties and affect crop yield and quality. A 4‐yr study was conducted on a Lihen sandy loam soil loam (sandy, mixed, frigid Entic Haplustoll) to evaluate the effect of tillage depth on sugarbeet (Beta vulgaris L.) root yield, root quality, and soil penetration resistance (PR). Tillage treatments consisted of no‐tillage (NT), shallow tillage (ST), and deep tillage (DT). Soil PR was measured with a penetrometer in 2.5‐cm increments to a 40‐cm depth at three locations within each plot. Roots were hand harvested from each plot and each sample consisted of roots of two adjacent rows. Sugarbeet root yield and adjusted sucrose yield were not significantly affected by the depth of tillage in 2008, 2009, and 2011. In 2010, root yield was significantly greater (16.5%) in DT than in NT. The average sugarbeet yields across 4 yr were 58.77, 60.30, and 63.03 Mg ha−1 for NT, ST, and DT, respectively. Root yield was lower in 2011 than other 3 yr due to cold and wet weather conditions in the spring. Soil PR values were significantly lower in DT than in ST and NT from 5‐ to 30‐cm depth. However, significant differences were found between ST and NT at the 5‐ to 7.5‐cm depth. Overall, DT enhanced soil physical environment but on average across 4 yr had no statistically significant effect on sugarbeet root yield and quality compared to both ST and NT practices, though a trend was noted that as tillage depth increased root yield increased.