Soybeans turned higher in the closing minutes of Tuesday's trading after earlier falling to a one-week low. The gains were small and put the March futures in the middle of the previous day's lower range.

Corn tumbled after setting a six-month high in the overnight session, while lightly trade winter wheat largely followed corn lower.

The three crops have had good gains in the past week, with both corn and soybeans setting six-month highs then. Winter wheat set a four-month high a week ago.

Soybean export sales may slow as China will close during its new year celebrations that start on Friday and continue into early next week.

In other markets, equities were higher, with the Dow Jones Industrials up about 136 points when the crops closed. The dollar was a little higher but remained within the previous day's trading range. Crude oil was up about 50 cents a barrel in the early afternoon, while gold was about $7 lower.

Export highlights (according to the U.S. Department of Agriculture and Reuters) included:

- On Tuesday, USDA said unknown destinations bought nearly 6 million bu. of soybeans, which included 3.78 million bu. of the 2016 harvest and 2.2 million bu. of the 2017 crop. Unknown destinations also bought 4.9 million bu. of 2016-17 corn.

- USDA said Mexico bought about 4.1 million bu. of soybeans that included 1.54 million bu. of the 2016 crop and about 2.6 million bu. of the 2017.

- Ethiopia seeks to buy 720,000 metric tons of optional-origin milling wheat, with offers due by Feb. 3. Shipment will be within three months of when letters of credit are opened, which could be March to May.

Corn set a six-month high overnight but could not stay there, and March closed down 1.6% for the day.

Corn export sales have been active for the past two weeks, including Tuesday's sale to unknown destinations. That business may slow as buyers shift to Argentina and Brazil, which will be harvesting soon. USDA earlier this month estimated Argentina's and Brazil's corn crops at 86.5 million and 36.5 million mt, respectively, unchanged from December.

One crop forecaster on Tuesday raised its estimate for 2017 U.S. corn acreage and lowered its soybean acreage from its previous forecasts.

The dollar value of corn at China's Dalian market for May was down slightly at $5.82/bu. European corn for March was firm at $4.65/bu. The prices reflect conversions from local currencies and metric tons.

The Chicago Board of Trade (CBOT) estimated Tuesday's corn volume at 282,820, compared with Monday's actual volume of 237,591. Open interest in Monday's market increased by 12,722, with March down 143 and May up 4,916.

March corn closed 6.25 cents lower at $3.6325/bu., and May was down 6 cents to $3.705.

What to look for: Corn was unable to hold above the 200-day moving average near $3.70/bu. and now is not far above support at the 20-day average near $3.58.

Soybeans made a swift turnaround in the final minutes of trading to close fractionally higher. March had dropped to last week's low but recovered to finish within Monday's range.

China's new year holiday, which starts on Friday, is on traders' minds. Also, rain in Brazil may slow the harvesting of that big soybean crop. Forecasts have rain there this week and next week. Argentina, which will harvest in March, is dry this week but may have a few showers next week.

China's soybeans for May delivery at the Dalian market were lower, at the equivalent of $16.71/bu.

CBOT estimated Tuesday's volume at 157,992, compared with Monday's actual volume of 152,288. Monday's open interest increased by 5,348 contracts, with March up 1,297 and May up 2,432.

March soybeans closed 0.75 cent higher at $10.585/bu., and May rose 1.25 cents to $10.68. New-crop November was up 0.75 cent at $10.26.

What to look for: Attention will be on South America, where Brazil is harvesting a huge soybean crop that will pull export business away from the U.S.

Wheat closed lower in light trading, largely following corn, with the largest losses in the soft red winter wheat.

Despite the lower close, soft red winter wheat stayed above a few key moving averages but remains a distance away from the 200-day resistance near $4.58. The export lineup for U.S. wheat is light. Ethiopia seeks optional-origin wheat in a tender that closes in early February.

For weather, the High Plains winter wheat areas are expected to be warm and dry for the next few days. The 6- to 10-day outlook also is mostly warm and dry.

CBOT estimated Tuesday's soft red winter wheat volume at 90,055, compared with Monday's actual volume of 83,007. Monday's open interest decreased by 490, with March down 1,298 and May up 1,362.

Chicago, Ill., March soft red winter wheat closed 6.5 cents lower at $4.2675/bu., and May was down 6 cents to $4.41. Kansas City, Mo., March hard red winter wheat dropped 3 cents to $4.4175/bu., and May slipped 3.25 cents to $4.5375. Spring wheat for March dropped 3.5 cents to $5.6025/bu., and May slipped a half-cent to $5.5675.

What to look for: It is a long way to the spring growing season, but the moisture now in the Plains could help winter wheat recover from the dry fall and early winter.