Effect of Soil Water Regime and Nutrient Supplies on Root Growth and Yield of Wheat in a Subsurface Compacted Soil

In a grasshouse experiment, subsoil compaction significantly decreased root mass density (RMD) in subsurface (0.15–0.30 m) soil layer, but did not affect it in the zone above the compacted zone. Irrigations at 30–50 kPa matric suctions and fertilizer application increased RMD in compacted layer. Differences in RMD due to subsoil compaction, however, were not reflected in wheat yield. Grain and straw yield were either same or higher with subsoil compaction. These data conclude that with precise regulation of water and nutrient supplies in the root zone, subsoil layers are not a constraint in wheat production.