Agronomy Library > Annual Weeds

Straight-talk on Seeding in 2009
Author: Ron Heller
Date Created: June 24, 2009
Last Reviewed: June 24, 2009
Noticeably, the way to farm our prairie landscape has changed dramatically since the introduction of direct seeding (DS) – No more bare fallow or seedbed cultivation, promoting renewal rather than depletion of precious soil organic matter! Growers can reap immediate benefits in saved time, labour and fuel costs while the soil stays moist and cycles nutrients better. This knowledge has come virtually from out of the dust. However, by no means does this imply that farming is easy. What worked well last year will still need twigging. For instance, under modern DS it may be possible for one grower to seed thousands of acres in a timely fashion, BUT the harvest system we call “combining” still remains unmatched to our planting methods, and highly-capitalized (when you think about the 6-figure price tags for such low daily-use of machinery in a compressed harvest season). The facts deserve more straight-talk. The creation of that perfect no-till seedbed depends on several factors that experience-alone will dictate. Nobody likes gouged stubble and clumped soil or restrictive residue in the seedrows. On the other hand, consistent seed-to-soil contact is equally hampered by disc hair-pinning or random placement by wide hoe-type openers. Yet, no-till is simply a clear focus on planting in a single-pass into undisturbed residue. It holds the best advantage when done correctly – something that won’t just happen. In my opinion, there’s a lot of tillage-baggage that still impacts the outcome for particular seeding systems. In a cold dry spring such as 2009, there’s indication of a few unfortunate failures, and much talk of re-seeding. So I managed to dig up a bit of evidence to find out why. These observations seem to flag many DS strengths, as well as a few weak-links in what I think was passed over in more normal seeding seasons: 1. Best seed germination occurred quite shallow (about an inch or less for most crops) in stubble left standing or only laid down lightly in a wheel track. This is perhaps the most challenging aspect of no-till. For a successful start in our short growing season, minimizing loose or lodged surface trash must become a “harvest task” in order to not compromise seed placement. Playing with residue in the spring is simply frustrating! 2. Ever notice how the soil beneath the seed furrow has reformed itself after displacement by the opener? What should it be like? – Look for a firm moist texture that can be scooped out by finger-tip. If the lower seedbed is hard and dry or glazed (so that scraping or digging with a knife is required?) it is likely limiting emergence. 3. Similarly, densely packed dirt on top of the seed is another tell-tale sign that something’s not right. Drill weight-transfer on packer wheels was troublesome for wet soils, especially under low organic matter levels or fine textured clay, and severe crusting occurred in some harrowed fields. Wet or dry, under higher levels of surface residue the seedbed was crumbly and pliable compared to stiff and lumpy in dusty “blackened” fields. Most emerging DS crops just needed more heat. When the term seedbed is fully understood, successful seeding happens more or less at the interface between “moist and firm below” and “dry and loose above”. DS does it best by low disturbance over time. For example, sod seeding is an extraordinary example of success in eliminating intensive tillage. When a wide sweep is dangled from a shank to be drug quickly through the field it only wastes moisture and fuel, while displacing soil and destroying residue. HOW, one should ask, does that even fit with the goals of seeding?