The government should prevent release of the market-moving U.S. crop reports and other agricultural data during the newly lengthened commodity trading day to curb the risk of price volatility, a farm-state senator said on Tuesday.

"Probably what the Department of Agriculture is going to have to do is release the reports in the two hours trade is not open," Iowa Sen. Charles Grassley, the first lawmaker to speak on the issue, said.

Adoption of a 22-hour trading day by the upstart InterContinental Exchange and the trend-setting Chicago Board of Trade means virtually all USDA reports will be released "live.

Grassley cited the possibility of wild gyrations if markets are open when reports are released and added, "I do not think the Department of Agriculture wants to be in a position to add to that."

Leaders of the House and Senate Agriculture committees, which oversee USDA and the futures markets, were not immediately available for comment. Grassley, No 4 in seniority among Republican senators, is a member of the Agriculture Committee.

Major USDA reports traditionally are released while markets are closed, giving traders and customers time to absorb the data before trading opened.

USDA officials say the are assessing what the 22-hour trading day means for release time of their reports but there will be no change in the near term. Most reports are issued in the early morning or mid-to-late afternoon.

The first major reports to be released during the long trading day would be U.S. and world crop forecasts on June 12. The pair of reports includes estimates of crop output, usage, exports and stockpiles of food grains, feed grains, soybeans, soyoil, soymeal and cotton in major countries in 40 pages of tables and globe-spanning commentary.

R.J. O'Brien, the largest independent U.S. futures broker, urged ICE and CME Group, the parent of the Board of Trade, to call a two-hour recess on crop-report days so traders and customers can absorb the data "without producing unnecessary volatility and exaggerated price moves."

Other federal reports, such as unemployment rates or natural gas supplies, are not as comprehensive as the crop report, said O'Brien.

Nearly two decades ago, on May 10, 1994, USDA switched to early-morning release of the U.S. and world crop forecasts, formerly released at mid-afternoon. The change, sought by market participants, put U.S. exchanges first in line to trade on the data. The reports are prepared in a "lock-up" that begins before midnight to assure confidentiality. "However, NASS practices strong security procedures for all operations and all reports that are issued," said the National Agricultural Statistics Service in a 2005 history of its work. "The procedures and the levels of security are adapted depending on the time that is required to complete each reports and the types of individuals involved."

ICE began 22-hour trading of grain and soybean futures and options on Monday. CBOT aims to inaugurate a 22-hour day on May 21.