The most common response to hearing about the benefits of a particular product is, "That all makes sense, but how does it work in my soils or my location?"
While I don’t disagree, there are some minor adjustments that need to be made for a given crop or soil, but the basics for planting a seed correctly are universal.
A seed must absorb enough water to sprout and sustain itself while its early root system becomes established. It needs oxygen, because it isn’t photosynthesizing yet. Seeds require sufficiently warm temperatures to germinate.
Once germination begins, the seedling needs an easy path downward for its roots and an easy path upward for its shoot. After emergence, the young plant needs nutrients in adequate supply, in a location where the roots can absorb them with as few root restrictions as possible.
How your seeder is equipped and adjusted determines nearly all these things. The best way to place a seed in the soil is fundamentally the same regardless of the crop or which continent you’re farming on. The many different brands of seeding equipment we have today are simply design trade-offs — imperfect ways of achieving adequate emergence and later yield.
Optimum seeding depth will vary, of course, but it varies in predictable ways. It isn’t simply a random list of crop- and location-specific details. Small seeds generally need to be placed shallower than large seeds because they have fewer energy reserves with which to push a shoot to the surface. Seeding can and should generally be deeper when conditions are warm and dry than when they are cool and wet.
There are also universal truths:
It’s rarely a good idea to firmly pack the soil above the seed. That only slows germination, increases disease pressure, and makes it more difficult for the shoot to emerge and, in grass crops, for crown roots to develop.
It’s always a good idea to establish some seed-to-soil contact at the seed's location. That ensures rapid and uniform germination among the viable seeds.
And all crops benefit from uniformity — not just corn, sunflowers, and cotton. The yield effect may not be as large in crops such as wheat or soybeans, but there is still an advantage when plants emerge and develop at the same rate as their neighbors. As seed genetics and yield improve further, this will come into the spotlight.
There are also some things dictated simply by the physical world. For example, if you want precise seed depth, depth must be measured close to the point where the seed-placing action occurs. This also prevents dust, duff, and chunks of sidewall from getting in ahead of the seed.
The importance of excellent seed-to-soil contact also varies. Warmer climates and poorer soils generally require more attention to this detail. Likewise, row cleaners and pop-up fertilizers tend to be more important when planting into cooler soil than when planting into warm soils.
The actions required to do a good job of no-till seed placement are the same whether you're planting corn or canola, farming clay or sand, working with high organic matter or low organic matter, or farming in Canada, South Dakota, or Colorado. The seeds and seedlings all need the same basic environment to establish and prosper.
