Seed furrow sidewall smearing by double disk openers

eed furrow sidewall smearing by planter double disk openers in clay loam and loam soils was investigated in field and growth chamber experiments. Treatment variables were row preparation, soil moisture, and planting period. Evaluation parameters were soil bulk density, air permeability, cone index, emergence rate index and total emergence, and plant dry matter weight. The experiments were conducted in somewhat poorly drained soils near Ames, Iowa. The fields were not cultivated before planting and the residue from the previous year's corn was removed. Experiments were conducted in two cropping seasons. Each experiment consisted of a factorial design of three coulter treatments, three moisture ranges and three planting periods. Crop growing seasons were divided into three planting periods. Treatments were replicated three times using a split-split design. After planting in the field, undisturbed soil blocks were removed and transferred to growth chambers. Soil blocks were not watered and left for 28 days at...