Making the Move to Direct Seeding

Direct seeding offers several benefits over conventional tillage, including improved yield potential and time savings for field operations. However, the change to direct seeding is a change to a different cropping system. It requires a new approach to crop residue, weed and fertility management. It may also require crop rotation changes to prevent specific pest problems that were kept in check by tillage. If you plan to seed directly into standing stubble, here are a few things to keep in mind.

Where to Start

• Consult government or private industry sources for information on how direct seeding will work for your specific situation. This includes such factors as your equipment inventory, crop rotation and soil types.
• Good crop residue management is essential. Straw and chaff must be removed or spread evenly across the field at harvest. Ensure that the combine can spread crop residue over the entire width of the cut.
• Starting with a cereal crop planted into oilseed or pulse stubble, with well-spread residue, makes the transition to direct seeding easier. Pulses and oilseeds produce less residue cover, so fields tend to warm faster in the spring compared to cereal stubble fields. Starting with a larger seeded crop allows you to carefully check the planting depth before moving to a shallow-seeded crop like canola. See also Residue Management for Successful Direct Seeding, Agdex 570-4, and Equipment Issues in Crop Residue Management, Agdex 519-4.

• Crop rotation is the best way to control disease, weed and insect pests in direct-seeded fields. Rotation also enables the use of alternative herbicide combinations which can help prevent the development of herbicide-resistant weeds. A good rotation may include spring and winter cereals, oilseeds, pulses and forages. See also Controlling Wheat Diseases in Direct Seeding Systems, Agdex 519-9, Controlling Barley Diseases in Direct Seeding Systems, Agdex 519-23, and Controlling Field Pea Diseases in Direct Seeding Systems, Agdex 519-23.
• Crop rotation also enable the use of alternative herbicide combinations, which can help prevent the development of herbicide-resistant weeds.

• Direct seeding systems rely more on herbicides for weed control. An effective spraying system is a must.
• Carefully assess whether the weed problems on a specific field can be economically controlled without tillage. Some perennial weed problems may be very difficult to control in a direct seeding system.
• Direct planters with minimum soil disturbance ground openers require a pre-seeding herbicide treatment. High disturbance ground openers achieve some but not necessarily complete mechanical weed control during seeding. See also: Control of Winter Annuals in Reduced Tillage Systems, Pre-seeding Weed Burn-down in Direct Seeding, and Perennial Weed Control in Direct Seeding Systems.

• Placing fertilizer near the seed is important in direct seeding systems to avoid stranding crop nutrients at the soil surface.
• Under direct seeding, organic materias from the previous crop may decompose more slowly. Thus, for the first few years after changing to direct seeding, monitor fertility levels closely and use recommended fertilizer rates to prevent nutrient deficiencies early in the growing season. This deficit will be corrected in time as soil organic matter levels reach a new equilibrium. See Direct Seeding Implications for Nutrient Management.
• Granular fertilizer can be applied with the seed, placed between a paired seed row, or placed to the side of the seed row. Anhydrous ammonia can also be applied at seeding if well separated from the seed. See Anhydrous Ammonia Use at Seeding, Agdex 519-20. Check the recommended safe rates of seed-placed fertilizer for each crop and your specific soil type, moisture level and seeder design. Each ground opener type has a unique seed and fertilizer spread. Too much seed-placed fertilizer can reduce crop germination and vigour. See Alberta Fertilizer Guide, Agdex 541-1 for more information.
• Applying all of the seed and fertilizer in a single pass is only one option for a direct seeding system. Another possibility for most crops is to seed-place some of the nitrogen and all of the phosphate. The remaining nitrogen can be applied in a separate operation. The most popular method is to use a knife-type or disk opener in the fall or early spring. By spreading the workload, field efficiency is increased during the critical seeding period. However, this method can cause seedbed drying. It can also cause difficulty clearing loose stubble during seeding, and increased weed growth in the early spring.

• You may be able to adapt your current planter to seed directly into canola, pea or cereal stubble if the crop residue is well chopped and spread. For example, a hoe drill or an air seeder can be modified by adding specialized ground openers or mounted packers.
• Find out which type of ground opener and packing design works best for the soil and crop conditions on your farm. Specialists, farmers and equipment dealers are all good sources of information. See Ground Opener Systems, Agdex 519-24.
• If crop residue is a problem, heavy harrows may help distribute straw and reduce plugging in planters. Fall harrowing as soon as possible after harvest will minimize the damage to standing stubble. Rotary or flail mowers can also be used to shred heavy residue before planting. See Handling Difficult Crop Residue Conditions in Direct Seeding Systems, Agdex 519-2.
• If you need a new planter, field test several different machines on your farm. Demonstration units may be available from your equipment dealer or municipal agricultural service board. Custom application is also a good option.