One‐Time Tillage of No‐Till Crop Land Five Years Post‐Tillage

Continuous no‐till (NT) can be beneficial relative to tillage with fewer field operations, reduced erosion, and surface soil improvement. Field research was conducted at two locations for 5 yr in eastern Nebraska to test the hypotheses that one‐time tillage of NT can result in increased grain yield, reduced stratification of soil properties persisting for at least 5 yr, a net gain in soil organic carbon (SOC), and a restoration of the soil microbial community to NT composition. Stratification of soil test P, SOC, and bulk density was similar for all tillage treatments at 5 yr after tillage. Water stable soil aggregates (WSA) were not affected by tillage treatments except that there was more soil as macroaggregates at one location in the 5‐ to 10‐cm depth with moldboard plow tillage (MP) compared with NT. Tillage treatments had no effect on SOC mass in the 0‐ to 30‐cm depth. Soil microbial biomass was greater at the 0‐ to 5‐cm compared with the 5‐ to 10‐cm depth. Biomass of bacteria, actinomycetes, and arbuscular mycorrhizal fungi was greater with NT compared with one‐time MP at one location but not affected by the one‐time tillage at the other location. Microbial community structure differed among tillage treatments at the 0‐ to 5‐cm depth at one location but not at the other location. Grain yield generally was not affected by tillage treatment. One‐time tillage of NT can be done without measureable effects on yield or soil properties.