Influence of Tillage Management in a Stubble Mulch Fallow‐Winter Wheat Rotation With Herbicide Weed Control1

Abstract Studies were conducted near Pendleton, Oregon, from 1962 through 1965 to compare the effect of no‐tillage and various times of stubble mulch tillage operations during the fallow season on moisture storage, nitrate accumulation, and winter wheat (Triticum aestivum L.) yields. Weeds were controlled during the spring and summer of the fallow year with nonpersistent herbicides. Plots which had received no tillage tended to store less moisture and to accumulate less nitrates than tilled plots. During the second crop year, yields from nontilled plots were significantly reduced compared to yields from tilled plots. Conventional stubble mulch tillage including two or three rod weedings tended to be the optimum tillage treatment. Delaying the first tillage until June decreased moisture storage in comparison to other tillage treatments.