US grain, soy futures end lower; USDA winter wheat ratings decline

* Markets react calmly to Iran drone attack on Israel

* China demand for soy and corn falling

* U.S. winter wheat seen 55% good-excellent, from 56% previously

CHICAGO, April 15 (Reuters) - CBOT soy, corn and wheat futures closed lower on Monday, anchored by ample grain supplies, slow export demand and a decline in crude oil futures after concerns eased about Iran's weekend drone attack on Israel, analysts said.

Crude oil futures fell on Monday as the risk of a broader conflict in the region lessened for now.

Traders "bought the rumor and sold the fact," said Mike Zuzolo, president of Global Commodity Analytics, noting that corn, soybeans and wheat rallied on Friday before Monday's sell-off. Corn and soybeans sometimes follow trends in crude oil given their respective roles as feedstocks for ethanol and biodiesel fuel.

On the Chicago Board of Trade, May soybeans settled down 15-3/4 cents at $11.58-1/4 per bushel. CBOT May corn ended down 4 cents at $4.31-1/2 a bushel and May wheat fell 4-1/2 cents to finish at $5.51-3/4 a bushel.

A stronger dollar added to bearish sentiment in grains. The greenback reached its highest level since early November against a basket of currencies after U.S. retail sales increased more than expected in March.

After the close of the CBOT, the U.S. Department of Agriculture rated 55% of the U.S. winter wheat crop in good to excellent condition, down a percentage point from last week but still the highest for this time of year since 2020.

"Fifty-five percent good to excellent is considered pretty historically good, condition-wise," said Randy Place, analyst with the Hightower Report.

The USDA said the U.S. corn crop was 6% planted, ahead of the five-year average of 5% but behind an average of trade expectations for 7%. In its first estimate of U.S. soybean planting progress for 2024, the USDA said the oilseed crop was 3% seeded, ahead of the five-year average of 1%.

Russian and Ukrainian grain exports continue to escape major attacks, but Reuters learned that Russia and Ukraine reached a deal in March to ensure the safety of shipping in the Black Sea. The deal was scuttled, however, when Ukraine pulled out before it could be announced. (Reporting by Renee Hickman in Chicago Additional reporting by Michael Hogan in Hamburg and Peter Hobson in Canberra; Editing by Jan Harvey and Matthew Lewis)