Russia: Potential Winter Wheat Damage Due to Ice Crusting in Southern District

Fall and winter weather has been generally unfavorable for 2006/07 winter crops in Russia's key production zones, especially in the Southern and Volga Districts. Fall dryness delayed planting and hampered crop emergence and establishment, and severe January frosts destroyed winter wheat plantings in areas where shallow or patchy snow cover failed to provide adequate protection from the cold (see January 25 and February 10 articles). February ushered in a new threat: the likely formation of localized but potentially damaging ice crusts in parts of Russia's prime winter wheat region.

Microwave satellite imagery can be used to detect the formation of an ice crust either in the snow pack or just beneath the soil surface. The satellite sensor measures the level of polarization, which is essentially glare. Consistently high polarization levels can indicate the presence of ice. A common cause of ice crusting is the thawing and refreezing of water in the snow pack. This process can occur even when air temperatures are below freezing: heat from the ground can cause snow to melt near the soil surface, and the liquid can subsequent recrystallize to form an ice crust. Polarization anomaly data (i.e., current data compared to long-term normals) suggest the possible establishment of an ice crust during February in parts of southern Russia. The extent of "high-polarization" regions in European Russia fluctuated between mid-January and late February, but the consistently high readings in parts of the Southern and southern Volga Districts indicate conditions conducive to the development of an ice crust. The presence of an ice crust for a sustained period of time, perhaps as short as several weeks, can result in damage to dormant winter crops due to smothering. In an extreme example, extensive and persistent ice crusting in February and March of 2003 was largely responsible for the loss of over 25 percent of Russia's 2003/04 winter grain crop and the loss of roughly two-thirds of Ukraine's winter wheat. The situation for the current season is not nearly as widespread or severe as in 2003, but ice crusting is likely responsible for a deterioration of winter-grain conditions in parts of southern Russia. (Note that the glare from fresh snow typically boosts polarization values, and polarization data must be analyzed along with other data sources to determine whether high polarization readings are the result of fresh snow, or whether they indeed indicate the formation of an ice crust. For example, the unusually high polarization values in Ukraine during January and February were likely due chiefly to periodic snowfall.)

SovEcon, an independent, Moscow-based commodity analysis group, estimates Russia's sown winter grain area for 2006/07 at 13.6 million hectares, against 13.9 million last year, and reports that 18 to 20 percent of the crop was in poor condition in early March compared to 7 to 9 percent at the same time last year. Crop conditions are worst in the Volga District, which accounts for roughly 30 percent of the country's winter grains; appoximately 30 percent of Volga Valley winter grains are judged to be in poor condition. Rosgidromet, Russia's official crop-assessment agency, currently forecasts total winter losses at 18 to 20 percent compared to an unusually low 6 percent last year.

In Ukraine, meanwhile, the State Statistical Committee reports that farmers planted 6.1 million hectares of winter grains (against 7.5 million last year), including 5.1 (6.3) million hectares of wheat. Persistent fall dryness contributed to the sharp reduction in sown area. The Ministry of Agricultural Policy currently estimates winterkill (including losses related to fall dryness) at 12 percent, while some independent commodity analysts peg losses as high as 23 percent.

Satellite imagery indicates that most of the Southern District was snow-free as of March 20, but fields in the remainder of Russia's winter wheat region remained under snow. Snow cover was deeper than normal in the winter wheat areas of the Central and Volga Districts. Spring planting typically begins in early April in European Russia.

Current USDA area and production estimates for grains and other agricultural commodities are available on PECAD's Agricultural Production page, or at PSD Online. Initial estimates for 2006/07 will be released on May 12, 2006.