Potato Yield and Quality Response to Subsoil Tillage and Compaction

Abstract

Compacted soils have been found in intensively cultivated vegetable crop regions of Central Wisconsin, resulting in the wide scale use of subsoil tillage by growers. Th e goal of this project was to assess potato (Solanum tuberosum L.) yield and quality response to soil compaction and subsoil tillage. Potato quality factors evaluated were marketable yield, tuber size distribution, internal quality, and sugar concentration. A controlled small plot experiment and several fi eld scale experiments located in collaborating grower fi elds were conducted to assess potato and soil responses to subsoil tillage. Cone index profi les showed the potential for limited root growth below the compacted soil layer with values >2.0 MPa. Subsoil tillage reduced cone index values to <1.0 MPa below 33 cm in 2 of 3 yr. Total and U.S. no. 1 yields were not infl uenced by subsoil tillage. Likewise, no consistent diff erences were seen in the size distributions of U.S. no. 1 tubers across treatments, but subsoil tillage tended to decrease proportion of tubers 113 to 170 g. Subsoil tillage did not aff ect tuber glucose or sucrose concentrations at harvest or following storage for 120 d. Internal tuber defects were not aff ected by either compaction or subsoil tillage. Th e lack of consistent eff ects of subsoil tillage on potato yield raises questions regarding the validity of this practice. Th e recommendation that potato growers use subsoil tillage may be linked to increased tuber size distribution or factors other than yield such as water, nutrient, or disease management.

Root development in potato and carrot crops – influences of soil compaction

“…It should be noted that subsoiling is only relevant when it breaks a compacted soil layer, and in many of these experiments the level of compaction prior to cultivation was not described. In a more recent study by Copas et al (2009), under controlled compaction levels, no consistent effects of subsoil tillage was reported and support the conclusions by Stalham et al (2005). There are, however, also reports of significant yield increases following subsoiling.…”

Maize Canopy Photosynthetic Efficiency, Plant Growth, and Yield Responses to Tillage Depth

“…Compacted soils reduced the plant height of field corn, and decreased the aboveground biomass in potato, snap bean, cucumber, and cabbage [45]. Subsoil tillage has been recommended to use across the United States to alleviate the negative effect of a compacted layer on potato (Solanum tuberosum L.) productivity [46]. Compared with no-till plots, subsoil tillage dramatically decreased foliar symptoms of sudden death syndrome for soybeans [47].…”

Soil compaction problems and subsoiling effects on potato crops: A review

“…Copas, Bussan, Drilias, and Wolkowski (2009) conducted a controlled small‐plot experiment and field‐scale experiments in loamy sand soils to assess the responses of potato yield and quality and soil physical properties to subsoil tillage for 3 consecutive yr. In the small‐plot experiment, soil strength as measured by penetration resistance of a compacted soil treatment (achieved by repeatedly driving a heavily loaded truck and attaining a penetration resistance of ≥435 psi) was significantly higher than non‐compacted treatments throughout the soil profile.…”

“…However, just as many studies have shown that both tuber yield and quality were either unaffected or slightly reduced by subsoiling, even in severely compacted soils (Buxton & Zalewski, 1983; Copas et al., 2009; Henriksen, Mølgaard, & Rasmussen, 2007; Holmstrom & Carter, 2000). Such results are often attributed to clod formation, reconsolidation, high moisture content during bedding, topographic variations, and compaction variation among wheel‐trafficked and non‐trafficked furrows.…”