Relationship of Tillage and Fertilization to the Yield of Alfalfa on Freeman Silt Loam1

Abstract

AbstractLiming (L) and fertilizing with phosphorus (P) and sulfur (S) were more effective than any other combination (LP, LS, PS, LPS + N) of fertilizers used in increasing the productivity of alfalfa. Tillage and seeding practices were associated with degrees of frost heaving of alfalfa, but had no effect on production of alfalfa in the second and third cutting years. Plant heaving at the end of the first year following seeding was decreased by seeding alfalfa without a companion crop, by deep tillage, and to some extent by surface compaction.Loosening the soil to a depth of 122 cm reduced average bulk density of the subsoil from 1.65 g/cc to approximately 1.45 g/cc. This treatment permitted greater water storage in the subsoil and an increased availability of subsoil water to plants through more extensive root penetration into the loosened zone.Fertilization, combined with deep soil profile modification (with topsoil and subsoil mixed), produced the highest yield of alfalfa. The unfertilized deep‐tilled soil produced more alfalfa than the fertilized shallow‐tilled soil.Mixing the topsoil and subsoil together to a depth of 122 cm sustained greater yields than tilling to the same depth but replacing topsoil and subsoil in their original sequence.