*

Soy near 2020 lows on weak demand and beneficial weather

*

Corn slips on beneficial rain in the U.S. Midwest

*

Wheat continues slide on advancing U.S. harvest and cheap

Russian exports

(Updates byline, changes dateline, updates prices, changes

throughout, adds bullets)

By Heather Schlitz

CHICAGO, July 30 (Reuters) - Chicago corn, wheat and

soybean futures fell on Tuesday to trade near their lowest since

2020 as U.S. crop data and weather charts reinforced

expectations of big harvests while worries about Chinese demand

also hung over commodity markets.

Rains forecasted for the U.S. Midwest are expected to

benefit the region's crop, which notched high condition ratings

in the U.S. Department of Agriculture's Monday crop progress

report.

The most-active soybean contract on the Chicago Board of

Trade (CBOT) was down 16-3/4 cents at $10.22-3/4 per

bushel as of 1545 GMT, near Monday's low of $10.18 - a level not

seen since October 2020.

CBOT corn slipped 5 cents to $4.07-1/4 a bushel,

hovering near a November 2020 low.

CBOT wheat fell 6-3/4 cents at $5.24-1/4 a bushel,

near an August 2020 low. Wheat futures have been under pressure

from an advancing U.S. harvest and low Russian wheat prices.

In its weekly crop progress report on Monday, USDA rated 67%

of soybean crops and 68% of corn as being in good-to-excellent

condition.

"There's no real weather threats right now," said Jim

Gerlach, president of A/C Trading.

Rains have also allayed concerns about hot, dry weather in

the previous week damaging the corn and soy crop.

"We've seen a pretty sharp turnaround in the discussions

about weather," said Rich Nelson, strategist at Allendale.

U.S. farmers continue to sit on large supplies of old-crop

soybeans and corn, adding pressure to prices.

"You've reached a seasonally tough time of the year where

anyone who hasn't sold has to sell before harvest to free up bin

space," said Gerlach.