Brunel Sabourin, Antara Agronomy Services Ltd. – Spring (March) Pulse Beat 2020
At St. Jean Farm Days this year, Dr. Timi Ojo, meteorologist with Manitoba Agriculture and Resource Development, asked producers whether they thought 2019 would be remembered as a dry year or a wet year.
If we look at the growing season, for many areas, it was a record dry year. Although we received average rainfall overall, most of the rain fell too late to help this year’s crop and made a mess of the second half of harvest. For all the problems the rains caused, though, it may turn out to be a blessing in disguise for the 2020 growing season.
Many producers were able to finish harvest and are happy to put 2019 behind them. But for others, there will still be some crop to harvest ahead of the 2020 planting season. Many more will have residue, ruts and compaction to deal with. Add the fact that little to no fertilizer was fall-applied across western Canada and the upper midwest region of the U.S., and fertilizer supply problems may add another degree of complexity to an already challenging spring.
There are five important factors that producers will need to consider on a field by field basis as they plan their spring: weather, equipment, soil test levels, residue and unique field characteristics.
One of the first factors to consider is whether the field has any residue that will need to be managed. There is usually a price to pay for spring fieldwork. It tends to dry out soils and in the case of heavy clays, cultivating wet soils causes compaction and can wreak havoc on seed to soil contact and good emergence. Imagine the effects of stepping on a loaf of bread and squeezing the air out of it. It will eventually rebound somewhat, but never to its original state (Figure 1).
I recently read a book on the history of Lake Aggasiz in which geologists point out that much of Manitoba is still decompressing from the last Ice Age. It is believed that the Red River will eventually reverse its flow and head southwards, albeit not in our lifetime. If you are interested in the history of how the landscape in Manitoba was formed, I highly recommend the book titled Lake Agassiz, The Rise and Demise of the World’s Greatest Lake by Winnipeg author, Bill Redekop.
Corn residue will present the biggest challenge this spring. Burning may be an option considered by some if we are unable to incorporate it properly. If the field was wet when harvested, there will also be ruts to contend with. Vertical tillage tools and highspeed discs work excellent at sizing residue in the fall when conditions are dry. However, they may not work as well in the spring, especially if you are trying to stay shallow to avoid disturbing too much soil. Loamy or sandier soils are a lot more forgiving than clay soils.
Shallow cultivation will also have a limited effect on the compaction of last year’s harvest. We might be able to cover the ruts somewhat, but they will still reduce yields. Producers will have to weigh the negative effects of tillage against the negative effects of the ruts. Do you live with partial ruts on 20% or less of your acres to realize the full potential on the other 80%? Or do you risk affecting yields across the entire field?
The second factor to consider is what are the nutritional needs of the crop. Ultimately, we need to determine how much fertilizer we need to apply and what is the best placement. Fertilizer quantity will depend on the crop, yield goals and residual soil test levels. If field levels are healthy and/or you as a producer have fertilized aggressively in the past, you may be able to reduce rates or afford less optimal placement methods. See Figures 2 and 3 for a few related examples from our agronomy benchmarking program.
That leads us to our third factor, which is equipment. We have already mentioned vertical tillage tools and highspeed discs to incorporate residue, but we must also consider fertilizer applications. Available equipment options will dictate how we place our fertilizer, seed safety and logistics. Today’s higher yields require more fertilizer that push the limits of what can safely be placed with or near the seed. Mobile nutrients can be broadcast, but nutrients like phosphate or potash will significantly lose their effectiveness if not placed in or near the seed row. Can we apply our fertilizer needs before, during and/or after planting? The golden standard of efficiency is to band fertilizer near the seed row, but the trend towards narrower openers and wider row spacings often mean little to no fertilizer can be placed in the seed row. There are many specialty fertilizers on the market today that increase nutrient efficiency and seed safety, giving us more options in a tough spring.
The final two factors are closely tied together — weather and unique field characteristics. These can affect timely field operations and how to tackle them. When it comes to weather, the big question generally is whether it will be an early or late spring? Will it be wet or dry? Ideally, every producer wants an early, dry planting window followed by nice spring showers that warm up soils and get the crop growing. This spring, we will have the challenge that soils were saturated at freeze up. Although we have below-average snowfall in much of Manitoba, producers in some parts may still have to contend with spring flooding due to higher snowfall amounts south of the border. Rainy weather will compound this effect, delaying seeding, and add further strain to the fertilizer supply chain.
Unique field characteristics, such as soil texture and topography, will also affect your plans. Work in fields prone to spring flooding or standing water will likely be delayed. Heavy textured soils stay wetter, longer. We will have to plan the logistics of spring operations accordingly. Maybe a light cultivation could help with drying out soils in certain cases. I realize this contradicts a few of the points I made earlier, saying spring cultivation is bad, but there are exceptions and grey areas to every rule.
At the end of the day, producers should be prepared with a plan to tackle whatever scenario ends up playing out. This may mean having a plan A, B, and C at the ready. Many retailers and agronomists are encouraging producers to take home fertilizer now if they can to help mitigate the risk of a supply chain disruption. With our short growing season, the optimal planting window is small in a good year and even smaller in a challenging one. A successful season begins with planning long before the seed is in the ground.
