The Effect of Two Direct Seed Drill Openers, Straw Management, and Seeding Rate On the Performance of Spring Canola and Mustard.

Concerns over soil erosion, soil quality, and sustainability of farming have induced a significant number of Pacific Northwest growers to adopt direct-seeding practices.  To expand the use of conservation farming technologies, growers need non-cereal rotation crops, and Brassicaceae crops are good candidates to fill this niche in the dry land regions of the Pacific Northwest. However, growers have many questions regarding how best to produce Brassicaceae crops in a direct seed system.  To help answer some of these questions, we designed an experiment to determine whether seeding rates and straw management interact with drill opener type.  Trials were planted at Genesee, Idaho in 2006 and 2007 using a plot drill with five Case-IH SDX disc openers and another plot drill with five Flexi-Coil Stealth paired-row shank openers.  Both drills have 10-inch row spacing.  ‘Clearwater’ spring canola (Brassica napus), ‘Pacific Gold’ oriental mustard (Brassica juncea), and ‘IdaGold’ yellow mustard (Sinapis alba) were planted at three seeding rates into three straw management treatments: (1) no straw treatment, (2) mowed straw, and (3) harrowed straw.  The previous crop in both years of the trial was spring barley.  Fertilizer placement was 1 inch below the seed and between the pair rows with the Flexi-Coil opener.  A two-pass operation was used with the Case IH SDX drill that placed the fertilizer between the seed rows and 1 inch below the seed.  Neither drill opener had problems with the levels of straw residue encountered in this study.  Both types of openers appear to be acceptable for spring canola and mustard seeding; although the use of the Flexi-Coil shank opener did produce higher yields in 2007.  Differences in yields between the openers did not appear to be due to differences in plant populations; in one year the Flexi-Coil opener produced higher populations but not better yields, and in the other year it produced better yields but not higher populations.