Low spring soil temperatures commonly restrict the early growth of corn (Zea mays L.) in the northern Corn Belt. A quantitative assessment of the effects of tillage and residue management practices on soil temperature would improve tillage recommendations in this region. The effect of tillage and surface residue cover on seedbed soil temperatures and subsequent corn growth were studied at four sites in the northern Corn Belt that differed widely in soil characteristics including drainage, texture, slope, and organic matter content. Tillage systems included no‐tillage, chisel plow, moldboard plow, paraplow, ridge plant, and wheeltrack plant. A wide range of surface residue cover was imposed on each system at three sites. Corn emergence and leaf number to the six‐leaf stage were closely related to percent in‐row cover and air temperature growing degree days (air GDD) through their mutual relationship to soil temperature growing degree days (soil GDD) at all sites. For a given site and year, percent in‐row cover following planting was the major factor affecting corn growth rate until the six‐leaf stage. Corn planted under high percent residue cover required more time and consequently more air GDD to reach the six‐leaf stage. This added time represents a growth delay that can be expressed as the additional air GDD required to reach the six‐leaf stage. Such delays were related to increased grain moisture and decreased corn grain yield when net cumulative air GDD were less than the threshold value of 1319 and water stress was minimal. In‐row residue cover due to tillage and previous crop can have a major impact on the growth and development of corn in the northern Corn Belt. These factors should be considered in selecting tillage systems in this region.

We investigated soft tissue facial asymmetry in normal and syndrome-affected individuals ranging in age from 1 year to adulthood. The purposes of our study were to determine if facial asymmetry was greater in syndrome-affected individuals than in normal individuals and, if true, to distinguish those measurements that could be used in routine screening to identify the presence of syndromes in uncertain patients and, lastly, to investigate the causes of measurement asymmetry at the level of the landmarks. The last purpose was possible because we used a stereophotogrammetric method with which the three-dimensional (3D) landmark positions were obtained. In the statistically significantly different measurements, those from the right side were dominant, with one exception in each group, except normal males. In all groups the landmark analyses demonstrated the same trends, and while there was far less patterning in the 3D coordinates, these results were also consistent between the four groups. We compared the statistical findings of the 3D coordinates and measurements and found that there was no predictable relationship between significant findings in the landmarks and the measurements. In particular, we noted that statistical differences in measurements did not infer significant differences in the positions of the landmarks between the right and left sides of the face. Both the normal and syndrome-affected groups appeared to be equally canalized and similarly affected by developmental noise: When the bilateral measurement differences of each syndrome-affected subject were compared to the limits of normal asymmetry, less than 10% of the comparisons exceeded the norms.

This study was conducted to elucidate the long‐term effect of dewatered sludge application on a silty clay loam soil, which possesses poor permeability and other undesirable physical properties. A Zimpro®‐processed dewatered sludge was applied in early 1977 at treatment rates of 0, 11.2, 22.4, 44.8, and 112.0 Mg ha−1 (dry solids basis) to a Kewaunee silty clay loam soil (Typic Hapludalf). A sixth treatment was an annual application of 22.4 Mg ha−1 from 1977 to 1982, resulting in a total input of 134.4 Mg ha−1. Bulk density, infiltration, hydraulic conductivity, and aggregate stability were measured $ yr after application (note: fifth year of annual sludge application at 22.4 Mg ha−1). The bulk density decreased by 0, 0.7, 3.5, 8.3, and 6.3% over the control for the 11.2, 22.4, 44.8, 112.0, and 134.4 Mg ha−1 of sludge treatment, respectively. The hydraulic conductivities of saturated soil cores were 0, 4.2, 45.4, 70.2, and 70.6% higher for the 11.2, 22.4, 44.8, 112.0, and 134.4 Mg ha−1 sludge treatment, respectively, over the control. The improved soil permeability was due to the enhancement of aggregate stability, which increased relative to the control by 3.3, 9.4, and 11.9% with the 44.8, 112.0, and 134.4 Mg ha−1 treatment, respectively. The in situ volumetric moisture content of the sludge‐treated soils was always higher than the control, especially after a prolonged period of evaporation. At 33.3 kPa or less, more water was released from soils treated with high rates of sludges. This indicated an increase in the volume of larger pores, which resulted in the higher hydraulic conductivities. Lower rates of sludge treatments (11.2 and 22.4 Mg ha−1) had no effects on the soil physical properties after 5 yr. Small yearly applications improved the soil physical properties equally as well as a single large application.