Effects of Reduced Tillage Practices on Continuous Wheat Production and on Soil Properties1

Abstract Acceptance of reduced‐ and no‐tillage systems in continuous winter wheat (Triticum aestivum L.) production has been limited in the past because of decreased yields, detrimental crop‐residue effects on seedlings and crop growth, and straw management problems. A field study conducted at Manhattan, KS for 3 yr assessed the effects of residue management (untreated, mowed, and burned), tillage treatments (conventional, reduced, and no‐tillage), and two methods of seed placement on plant density and grain yield of winter wheat, and on soil properties. The study area was mapped as Smolan sicl (fine, montmorillonitic, mesic, Pachic Argiustolls) and Wymore sicl (fine, montmorillonitic, mesic, Aquic Argiudolls). Lack of adequate seed placement due to the presence of surface residues under reducedand no‐tillage conditions reduced wheat yields. Increases in soil bulk density and resistance to penetration in no‐tillage treatments did not significantly affect wheat yields when seed was properly placed. Under relatively dry environmental conditions (1980–1981), no‐tillage wheat yield was higher than on conventional tillage (2.37 and 2.01 Mg/ha, respectively). Under such conditions, total soil water content in the upper 84 cm was higher on no‐tillage than on conventionally tilled plots. Maximum soil temperatures at the 5‐cm depth were 3°C lower on no‐tillage than on conventional tillage treatments.