GRAINS-U.S. wheat hovers near one-month low, soybeans edge up

* Rains boost wheat crop outlook in U.S. Plains

* USDA attache sees higher China soy imports in 2018/19 (Adds quote, updates prices)

LONDON, March 21 (Reuters) - Chicago wheat prices were hovering just above the prior session's one-month low on Wednesday as the market waited to see the extent to which rains may have improved the outlook for crops in the U.S. Plains.

The most-active wheat contract on the Chicago Board Of Trade had risen a marginal 0.1 percent to $4.53-1/2 a bushel by 1112 GMT, just above the prior session's one-month low of $4.50 a bushel.

The wheat market has been under pressure as rains fell across parched U.S. fields in the last few days. Some forecast models called for another round of moisture in the drought-hit southern Plains, where the hard red winter wheat crop is exiting dormancy and resuming spring growth.

The U.S. Department of Agriculture (USDA) late on Monday rated 11 percent of top winter wheat producer Kansas in good-to-excellent condition, down from 12 percent a week earlier. Wheat ratings also declined in Texas.

"While Mondays crop rating showed a new degradation of wheat conditions in the U.S., the last one did not take into account the rains of the weekend. That's why the crop rating of next week will be monitored closely," analysts Agritel said in a daily market update.

May milling wheat futures on Euronext were unchanged at 162.50 euros a tonne.

Soybean prices rose for a second consecutive session, with the CBOT's most active contract up 0.5 percent at $10.33-1/4 a bushel.

Dealers said the market derived support from a report issued by the U.S. Department of Agriculture's attache in China which put imports in the 2018/19 season at 100 million tonnes.

"The USDA's China import number is very large and the rain in Argentina seems to be too late to get a big turnaround in the crop there," a German trader said. "This looks like even more Chinese soybean purchases, provided there is no trade war."

Late season rains will halt further deterioration of drought-hit Argentine soybean yields, setting the stage for an estimated crop of at least 40 million tonnes after being trounced earlier in the season by extremely dry weather, experts said on Tuesday.

The 2017/18 crop year started with soy harvest estimates in the 55 million tonne range. But the drought has parched wide areas of Argentina's normally fertile Pampas grains belt since November and scorched some soy and corn fields beyond repair.

"We are seeing improved weather in the United States and Argentina," said one Singapore-based agricultural commodities trader.

"Soybean crop losses in Argentina have now been priced in and for wheat, there is no major global supply threat."

Corn prices were consolidating after their recent decline with the most active CBOT contract unchanged at $3.74-1/2 a bushel. (Additional reporting by Naveen Thukral in Singapore and Michael Hogan in Hamburg; editing by Richard Pullin and Louise Heavens)