EARLIER TO RISE
BENEFITS TO BUMPING UP SEEDING DATES
BY STAN BLADE, P.Ag.
During a recent visit to China, I had the opportunity to visit the Beijing Drum Tower (“Gulou”). This tower was originally built in the 13th century, during the reign of Kublai Khan, as the official time-keeping device for the people of Beijing. In addition to the daily keeping of time, the officials of the Drum Tower also had the responsibility of guiding the farmers of the region on timing of planting, crop development (with specification on grain-filling and other developmental stages), as well as harvest. I began to think about how we address the timing of crop production in Western Canada, and how research could assist in extending the growing season to produce higher yields.
If we agree that the goal is to increase crop yield, then it makes sense that the longer the plant is allowed to grow, the greater the amount of photosynthate (sugar) is produced within the plant’s plumbing. The more sugar available, the higher the likelihood that it will be transported into the developing seeds of the plant.
One way of extending the growing season is seeding early. The easy part is to confirm that early seeding pays benefits. Research across Western Canada on wheat, barley, canola, peas, flax and oats all shows that delayed seeding results in lower yields. There are some examples to the contrary, but the vast amount of research shows increased yield due to early seeding. The longer you wait, the more it costs you. So the goal is to find every possible way to stretch the growing season—while understanding that it is imperative that the crop is harvested before frost and snow.
Researchers have suggested a number of reasons for the success of early seeding: early seeding can result in earlier maturity, reducing possibility of losses due to early frost; early crops get a faster start and tend to be able to compete well with weeds; early-season moisture may be used more effectively; pest infestations may be lower; potential physiological damage due to high temperatures during flowering may be reduced. There is also the practical benefit of spreading out the workload by getting started earlier and varying the field operations (seeding, spraying, harvesting) in comparison to other crops sown later.
So how can you make the calendar work in your favour to maximize the growing time available to your crop? There is no doubt that fall-seeded crops make a lot of sense. Having the plant starting to grow in the field without the concern of doing a spring seeding operation provides a big advantage in stretching the growing season. However, the history of winter wheat has been hit or miss in Western Canada. Statistics Canada is predicting a 900,000-acre decrease from original projections due to the late 2013 harvest, which prevented late-summer/fall seeding. Work has been done on winter peas and fall-seeded canola, but there is still much more to do. Private companies have been marketing polymer-coated seeds that degrade over the winter and position the seed to germinate as early as possible in spring.
A less complicated level of innovation is selecting a crop that can either tolerate cold soil during spring planting or significant frost tolerance at the end of the growing season. The obvious course of action for producers is choosing crops that have a higher tolerance for low soil temperatures (such as peas). If producers are locked in to a specific crop type for rotational or marketing reasons, then there are also significant variations among cultivars that are suitable for early-season planting due to both cold tolerance and maturity. There are equipment choices that can make early seeding easier, since getting on the land in wet years can be a major issue that reduces available growing time.
What are the “next generation” options for extending our growing season in Western Canada? Research groups such as the Rodale Institute have investigated the long-term productivity of perennial cereals and oilseeds. In the future, perhaps we will be able to seed just once a decade, rather than pulling out the seeder every year. Data from Michigan State showed that perennial wheat produced grain yields of 50 per cent of annual wheat and perennial rye yielded 73 per cent of annual rye grain yield. Perennial cereals may show yield changes over multiple years and may be subject to the buildup of diseases and insects over time. There are already significant biomass benefits in perennial systems, but more work needs to be done to develop cultivars that partition resources in grain.
How do we extend our growing season and increase crop yields? There are many choices now, and there will be more in the future, to maximize the production capacity of our fields.