When soil-incorporated herbicides were all the rage, tillage was the main operation on many farms. For some granular soil-applied herbicides, the recommendation was to cultivate several inches deep at high speed and to go over it twice at right angles. In the best black soils it was not uncommon to hear farmers say they had done seven trips over a field between combine and seeder. The excess tillage was enough to mess up even good soils and the more fragile sandy soils simply blew away in the wind.
Weather cycles also played a role. In general terms the 50s were wet, 60s dry and the 70s wet. The wet 70s coincided with high grain prices leading to affluence we also enjoyed in recent years
About the mid-1980s a drier cycle came along. It culminated in 1987-88 with back-to-back drought. 1988 was a complete bust for much of Saskatchewan and eastern Alberta. I recall driving the road from Brooks, Alberta, to Saskatoon in August 1988 and remarking that two old 90 Masseys would combine all the crop we saw in that drive.
During the 80s, 90s and early years of this century we had fair crops on just enough precipitation. Moisture conservation was a huge part of soil conservation. That weather cycle drove farmers to say “We must do it differently,” and the zero-till era was born. As I have said many times: the zero-till revolution was driven by farmers tired of dust in the air. Most of the seeder innovations came from farm workshops and farmers’ heads.
It was all about moisture conservation — high stubble caught the snow to give good seedbed moisture. And, with direct seeding, that moisture was still in place to make sure that the crop got off to a good start.
The low point of the last drought was 2001-02 — back-to-back dry years. In 2001 my pea yield was 12 bu./acre and in 2002 wheat was 20 bushels per acre.
Winter 2004-05 was the major weather change year. The big snow filled up the sloughs and they have been more or less full ever since. In this cycle, thanks to zero till, continuous cropping, new canola varieties and porking on lots of fertilizer, we have made good use of the water with high yields.
For several years now we have been in excess moisture territory — a hard pill to swallow for an old farm boy from dry old Milden, Saskatchewan. The big crops we have been growing have provided huge straw loads. We may need tillage from time to time to deal with that. Vertical tillage tools have come along to help with that job. Bare up a bit of soil and help to dry it out. Hard to swallow — but we may want to get rid of some water.
It’s not a religion
Zero tillage is a soil management practice, not a religion. Occasional tillage is not going to upset the work of years of strict zero till. Colleague Jeff Schoenau (University of Saskatchewan, Soil Science) and students did experiments a few years and found that occasional tillage is not detrimental.
As for vertical tillage — this old fossil really likes application of anhydrous ammonia to accomplish just that. It has been my nitrogen source for the past many years. The big rage in fertilizer industry circle is the 4Rs: Right source, right rate, right timing and right placement. For my money anhydrous ammonia is still the right source — and the cheapest!
For my money a pass with an anhydrous rig is a very good vertical tillage — very narrow knives penetrate easily, deal with excess straw and with an additional harrow a good seedbed is in place.
But, we must not revert to excess tillage and must always be aware that in the goodness of time this wet cycle will end and we will be back to drier times where moisture conservation is paramount.