CHICAGO (Dow Jones)--Chicago Board of Trade corn futures ended higher Thursday, continuing its technical recovery from recent lows.

December corn ended up 6 1/4 cents at $3.36 1/2 per bushel, and March corn ended 6 1/2 cents higher at $3.49 3/4 per bushel. In pit trades, speculative fund buying was estimated at 6,000 lots.

Speculative short covering was a feature following a failed attempt to pin prices in negative territory early on, analysts said.

The market has grown a little nervous of frost potential, and that was just enough to attract buyers on breaks, said John Kleist, broker/analyst with Allendale Inc.

U.S. Department of Agriculture reported Monday that only 21% of the U.S. corn crop was mature, well below the 5-year average of 55%. The low maturity rate shows a large deal of corn crops remain vulnerable to yield losses if a freeze would emerge in the next week, analysts said.

Technical buying was featured, with market shorts taking the opportunity to book some profits ahead of the end of the month and quarter, he added. Corn had trended lower on less-threatening weather outlooks previously.

Meanwhile, an absence of harvest pressure and seasonal buying patterns ahead of harvest provided some incentives for sellers to cover some shorts until uncertainties surrounding weather crop potential are cleared up in upcoming weeks.

T-storm Weather said after rain ends in the central U.S. over the next few days, a drier pattern will unfold. Coolness coincides with dryness for several days, which leads to minimums in the 30s Fahrenheit on Tuesday morning across the northeast third of the Corn Belt. Killing frost remains most probable to stay north of key crop areas.

A helpful drier and warmer pattern occurs for at least a few days later next week, which leads to improved harvesting and maturation rates. Warmth occurs in advance of a strong storm system. Once this storm system exits, a cooler pattern remains probable. Whether this leads to frost or not is highly debatable and frost is far from imminent. There are too many uncertainties leading into next weekend to have confidence in weather that follows beyond October 4, T-storm Weather said.

CBOT oat futures closed higher Thursday. December oats rose 3 cents to $2.19 a bushel, and March oats rose 3 1/2 cents to $2.32 1/2.

Ethanol futures ended mixed. November ethanol closed up 0.001 cents at $1.621 a gallon, and December ethanol down 0.003 cents at $1.615.

-By Andrew Johnson Jr., Dow Jones Newswires; 312-347-4604; andrew.johnsonjr@dowjones.com