Dryland no-tillage winter wheat response to planter type

Crop planting becomes increasingly difficult as surface residue amounts increase, as with conservation tillage, Planters for such conditions are available, but costly. With relatively low residue amounts, as for winter wheat (Triticum aestivum L.) and grain sorghum [Sorghum bicolor (L.) Moench,] grown in rotation on dryland, it was hypothesized that drills used under conventional tillage conditions could satisfactorily plant wheat into no-tillage sorghum residues. Objectives of this study were to test this hypothesis. The information would show whether different planting equipment is needed when switching to a conservation tillage system. Drills were John Deere 8200 (Deere and Co., Moline, IL) with single-disk, Graham-Hoeme PD-160 (United Farm Toolsi, Oelwein, IA) and Fabco M-10 (Fabco Ltd., Swift Current, SK, Canada) with double-disk, and International 7100 (J. I. Case, Racine, WT) with hoe openers. No drill provided 1.5 in. (target depth) of seed coverage; it was least (0.75 in.) with the John Deere, which moved more soil from the seed row than other drills. The number of seedlings emerged was not affected by drill types. Mean yields with the John Deere (2000 lb/acre grain; 4200 lb/acre residue) were lower than with other drills (2410 to 2670 lb/acre grain; 4900 lb/acre for residue). Differences in seed coverage depth and soil removal from the drill row possibly caused the yield differences. A suitable drill should be used for planting wheat under conservation tillage, but using a heavy-weight drill, as the Fabco, is not warranted when grain sorghum residues on dryland are similar to the amounts present under the conditions of this study (4900 lb/acre).