Maize (Zea mays ) seed orientation at planting can influence emerging leaf angle. If leaf angle were consistent among plants without leaf overlap, large numbers of these bilaterally symmetrical plants could be arranged to optimize light interception and possibly increase grain yields or maintain grain yield with a lower population. The objectives were to evaluate the effect of seed orientation in soil on the angle of maize leaves relative to the planted row and on emergence rate. Seeds were planted 2.5 cm deep in diverse combinations of flat, cotyledon down, cotyledon up, on their side, radicle up and radicle down. Each seed orientation was repeated 10 times. Data on days to emergence and leaf angle were collected. In three experiments, maize seeds planted flat with the cotyledon up resulted in homogenous and faster emergence, and maize leaves aligned perpendicular to the direction of the maize row. Similar results were achieved with maize seeds planted parallel to the row with the radicle down. Random placement of maize seeds resulted in random orientation of maize leaves and lower emergence rates. The effects of controlled leaf geometry could facilitate planting higher populations with the potential for increasing grain yield and/or allow the maintenance of grain yields while reducing seed rates.

Recent findings in the midwestern United States have shown that planting soybean [Glycine max (L.) Merr.] by early May often increases yield compared to planting in mid‐ to late May. These findings have encouraged earlier planting, but raise questions about how planting date might interact with other management factors. In 58 on‐farm trials in Illinois and Indiana in 2011 and 2012, we found that seed treatment (fungicide + insecticide + rhizobia inoculant) increased plant stand by 4200 plants per acre, with greater effects from early planting than with later planting. Seed treatment also increased yield, by an average of 1.2 bu/acre, but did not interact with planting date or maturity. Planting in late April increased yield only slightly (0.9 bu/acre) compared to planting in mid‐ to late May, and full‐season cultivars yielded 3.8 bu/acre more than short‐season cultivars. Full‐season cultivars yielded 5.5 bu/acre more than short‐season cultivars with early planting, but only 2 bu/acre more planted later. Yield of full‐season cultivars dropped by 2.7 bu/acre from early to normal planting, but those of short‐season cultivars remained unchanged. Although seed treatments may improve stands more with early planting, stands were adequate regardless of planting date or seed treatment, and the decision to use seed treatment can be made independently of cultivar or planting date. These results show that planting full‐season cultivars before short‐season ones, and perhaps choosing slightly fuller season cultivars in general, may improve soybean yields.

Correct placement of side dress nitrogen (N) fertilizer could increase nitrogen use efficiency (NUE) and maize yield production. Field studies were established to evaluate application of midseason (V8 to V10), variable liquid urea ammonia nitrate (28%), N rates (0, 45, 90 and 134 kg N ha −1 ) and different application distances (0, 10, 20 and 30 cm) away from the maize row on grain yield and NUE at Haskell and Hennessey in 2009, Efaw in 2010 and Lake Carl Blackwell, Oklahoma in 2009 and 2010. A randomized complete block design with three replications was used throughout the study. Results indicated that maize grain yield in sites with adequate rainfall increased significantly (p < 0.05) with N rate, and poor N response was recorded in sites with low rainfall. Across sites and seasons, varying side dress N application distance away from the maize row did not significantly (p < 0.05) influence maize grain yield and NUE even with no prep-plant applied. Environments with adequate rainfall distribution had better maize grain yields when high side dress N rates (90 and 134 kg N ha −1 ) were applied 0 to 10 cm, and a higher NUE when 45 kg N ha −1 was applied 0 to 20 cm away from the maize row. For low N rates (45 kg N ha −1 ), increased maize grain yield and NUE were achieved when side dress N was applied 0 to 20 cm away from the maize row at locations with low rainfall distribution. Across sites and seasons, increasing side dress N to 134 kg N ha −1 contributed to a general decline in mean NUE to as low as 4%, 35%, 10%, 51% at Hennessey, Efaw, LCB (2009) and LCB (2010) respectively.