August soybeans futures ended up 10 cents at $8.39-1/2 a bushel at the Chicago Board of Trade. The gains extended a recovery from Monday, after the market dropped about 6.7 percent last week.

Most active November soybean futures, which represent the US crop that will be harvested this autumn, ended up 9-1/2 cents at $8.55-1/4 a bushel.

Technical buying helped push prices higher after last week's slide, traders said.

The US Department of Agriculture raised concerns about this fall's harvest with a report on Monday that said 69 percent of the nation's soy crop was in good to excellent condition. That was down from 71 percent a week earlier and below analysts' estimates for 70 percent.

Soybean conditions are still the sixth highest since 1989, according to Radiant Solutions.

The recent decline in prices raised hopes for more export demand, traders said.

China, the world's top soy importer, has increasingly bought Brazilian supplies due to the trade war with the United States. However, US soybean prices are looking more competitive with Brazilian soybeans, according to traders.