Most no-tillers throughout the world are focused on trying to achieve a myth.
The myth is that no-tillage should put seeds in the same soil environment that tillage has been doing for hundreds of years, but to do it with seed openers on the planter instead of cultivating entire fields.
The myth arises from the belief that seeds need to be in contact with cultivated soil in order to germinate.
MYTH’S ORIGIN. This myth was probably started by Jethro Tull, who invented the seed drill in 1701. Tull believed that seeds absorbed small particles of soil in order to germinate and grow into plants, which we now know is simply not the case. What seeds do need to absorb, however, is water and oxygen. In tilled soils, seeds get water in its liquid form from contact with the colloidal water films that surround soil particles, which is why we have all come to understand that seed-to-soil contact is important when sowing seeds into tilled soils.
But it is the very process of tillage itself that has created this false dependency.
What the recent science of no-tillage has taught us is that water is also available in undisturbed soils as a vapor in the form of humidity that fills the pore spaces between individual soil particles. In tilled soils, vapor water plays virtually no part at all in seed germination because the aeration caused by tillage encourages most of the pore space vapor water to escape into the atmosphere before any seeds are sown.
By contrast, untilled soil still contains at least 99.8% relative humidity in the pore space air between the undisturbed soil particles — even in soil as dry as permanent wilting point, which is when the soil is too dry to allow plants to remove liquid water from it. If seeds can be slipped into untilled soils without allowing the pore-space water vapor to escape, soil water becomes available in both vapor and liquid forms, which is a luxury that has never been available to seeds sown into tilled soils.
ALTERNATIVE METHOD. Cross Slot low-disturbance no-tillage openers deliberately create horizontal slots in untilled soils without inverting the soil so as to purposefully retain the soil pore-space humidity. That is the reason why Cross Slot seldom fails to germinate seeds no matter how dry no-till soil is when it is drilled. It is also the reason why strip tillage seldom achieves more seed germination than fully tilled soils do.
Ironically, when no-tilled seeds have germinated, the embryonic plant roots then demand direct contact with soil particles in order to exchange nutrients with those particles. But they do not need any soil contact in order to germinate in the first place.
This also explains why seed testing laboratories throughout the world germinate their seeds on wet blotting paper in an atmosphere of 100% relative humidity without a single grain of soil anywhere near the seeds.
Understanding these processes sheds a new light on the design requirements of no-tillage openers. Producing strips of tilled soil is an unnecessary objective of a no-tillage opener. But slipping seeds under a surface mulch that covers undisturbed ground and traps an atmosphere of 90-100% relative humidity beneath is the best way of achieving fail-safe no-tillage seeding.
The sooner that farmers demand this from seed drill designers, the sooner no-tillage will reach its potential as the preferred, fail-safe method of growing the world’s food.
There is strong internationally-published science that backs all of the above facts. It is only a matter of time before farmers realize that such science does not lie.
Dr. C. John Baker is the CEO of Cross Slot No-Tillage Systems, creating the initial vision for Cross Slot in 1967 and co-authoring 4 books on the subject.