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.) andgrain sorghum [Sorghum blcolor (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-I60 (United Farm Tools, Oehvein, I A) and Fabco M-10 (Fabco Ltd., Swift Current, SK, Canada) with double-disk, and International 7100 (J. I. Case, Racine, WI) 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 Ib/acre grain; 4200 Ib/acre residue) were lower than with other drills (2410 to 2670 Ib/acre grain; 4900 Ib/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-weightdrill, as the Fabco, is not warranted when grain sorghum residues ondryland are similar to the amounts present under the conditions of this study (4900 Ib/acre).
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