Chilling impact on grain production

by Drew Lerner
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Record cold temperatures were observed in the U.S. hard red winter wheat production areas of the Central Plains April 24. It was the fifth time since the Easter Holiday that freezes threatened wheat production in the Plains and it was a perfect example of what has turned out to be a very cold start to the growing season in many Northern Hemisphere agricultural areas.

Warming in the Northern Hemisphere during May will be of great importance if there is going to be sufficient time for high latitude crop areas to get the degree day accumulations required for successful farming.

Cold weather was not just a North American phenomenon during April. The cold has been an ongoing anomaly in the Northern Hemisphere that began during mid-winter when a massively strong high pressure system anchored over the arctic began spreading unusually great amounts of cold air into the lower latitudes of Europe, Asia and North America. China and eastern portions of Russia experienced the most persistent, intense cold of the winter season with temperatures 3 to 6 degrees Celsius below average (Jan. 1-April 24, 2013). Subzero degree Fahrenheit temperatures (-18 C) were still occurring in northeastern China as recently as mid-April, and snow was still widespread across a huge part of Europe and the western Commonwealth of Independent States through the middle part of April. Much of Canada was still buried in snow on April 24, and the Prairies’ agricultural region is normally free of continuous snow cover by April 15 with southern areas snow free normally on April 1. The southern Prairies were expected to be snow free on May 1. Northern areas may have to wait a little longer.

Warming was observed in many of the world’s most important grain and oilseed production areas in late April, but the warm up was coming late with some spring crops expected to be seeded two to three weeks later than usual. In the case of some Canadian crop areas, planting will be as much as one month later than usual. That is a frightening statistic since durum wheat and some varieties of corn produced in the Prairies require more than 100 days of frost-free weather. If planting occurs on May 15, that means Canada’s Prairies would have to be frost free through Aug. 23. That might just work fine if planting were to occur on May 15. However, some of Canada’s durum, spring wheat, canola, chickpeas, sunseed, flax and other crops will not be planted until late May. A few areas will be lucky to get planted by June 1, and crops planted that late will need to be frost free at least through Sept. 8.

The normal first autumn freeze dates in the Canadian Prairies begins Aug. 31 and reaches most crop areas by mid-September. Planting on May 15 would leave plenty of time to get crops mature before a normal freeze event occurs in the autumn. However, what happens if summer is wet and cool, as it may be in 2013? Degree day accumulations would be below average and crops would end up immature even after 100 days have passed. A bigger “what if?” is in regard to the first frost and freeze event in the autumn. What if the first freeze comes in late August, as it has in some years? Damage to immature crops in a late August freeze would be significant for Canada.

Canada is only one place in the Northern Hemisphere where planting is late this year. Similar conditions are occurring in many U.S. crop areas, but especially in the northern Plains. Much of Europe and the northern Commonwealth of Independent States and northeastern China are experiencing similar conditions. This would not be a good year for autumn frost and freezes to come early in any part of the Northern Hemisphere, and a close monitoring of the spring planting season and summer temperatures will be warranted to determine the potential for production issues resulting from an early autumn.

In many years nature has a tendency to counterbalance anomalous weather. Extreme weather conditions of one kind or another in part of the growing season are often countered by the opposite anomaly later in the growing season. If that proves correct in 2013, there would be plenty of hope for a warmer finish to the growing season. However, the statistics based on cold March/April weather do not necessary support that theory.

In the top 11 coldest March/April periods in the northern U.S. Plains, nine of the following summers were cooler than usual and only two had a warmer biased summer. The cool weather in the Midwest seems to also correlate well with below to near normal temperatures during the summer, with only two warmer than usual summers in the years in which March and April were this cold in the northern Plains. Canada’s Prairies reported only three warmer than usual summers out of 12 years in which March and April were notably colder than usual like this year. However, in the case of Canada’s Prairies, there were many more years of near normal summer temperatures than in the U.S. northern Plains or Midwest.

Unfortunately, statistics for Europe and Asia are not readily available for a similar study, but World Weather, Inc. did notice that seasonal warming in northeastern China was advertised to be slow this year, according to the 18-year cycle, and that may eventually change the region’s current wet, cool bias to a drier pattern, with heat coming late in the summer.

The Northern Hemisphere temperature anomalies will have a significant impact on the 2013 production year. Crops getting off to a slow start will be lacking degree day units from the very beginning, making it important for timely rainfall and seasonal warmth to occur during the course of the spring and summer. Any failing to fulfill this need for warm weather will likely lead to lower production.

Dryness Still a worry in Russia, U.S. Plains

Early season soil moisture seems to be poised favorably for most grain and oilseed production areas in 2013, with the primary exception being in crop areas from eastern Ukraine through the lower Volga River Basin to western Kazakhstan and southeastern portions of Russia’s New Lands region, where drought remains.

Drought in a part of south-central Russia’s grain production region is moving into a fourth year of persistence. Very little snow fell during the winter, and early spring precipitation has been minimal recently. An above average temperature regime recently has already reduced topsoil moisture and raises a more serious potential problem with dryness later this spring and summer if the trend does not get reversed soon.

A close watch on rainfall in southeastern and east-central Europe may also be necessary this spring. Despite improved topsoil moisture from rain and snow in recent weeks, the subsoil moisture situation and most river, stream and water reservoir levels are still below average following dryness in the two previous summers. That places some concern on late spring soil moisture and warrants a regular occurring distribution of rain to avoid dryness from coming back across the region.

Much of the U.S. drought from 2012 has been eased in recent weeks, but deep subsoil moisture remains well below average across the Great Plains where the seed lies for a possible comeback in dryness later this spring and more likely during the middle of summer. Dryness is expected to rekindle in a part of the Great Plains during the summer and some of it may expand to the east again into a part of the western Corn Belt, but eastern U.S. crop areas should avoid a serious risk of drought, despite a drier finish to the growing season.