BEIJING, Aug 20 (Reuters) - China’s soybean imports from top supplier Brazil fell in July from the previous year, customs data showed on Friday, as poor crush margins weighed on demand. China, the world’s top buyer of soybeans, brought in 7.88 million tonnes of the oilseed from Brazil in July, down 3.7% from 8.18 million tonnes a year earlier, according to data from the General Administration of Customs. Chinese crushers stepped up purchases of soybeans from the South American country in the earlier months of the year, to profit from good margins, driven by a fast recovering pig herd. Demand from the livestock sector has, however, weakened lately as hog margins fell to negative territory on plunging pork prices. For July, China’s soybean shipments from all origins totalled 8.67 million tonnes, down 14.1% from the previous year. China also imported 42,277 tonnes of soybeans from the United States in July, up from 38,331 tonnes in the same month a year earlier, according to customs data. (Reporting by Hallie Gu and Shivani Singh; Editing by Himani Sarkar) Our Standards: The Thomson Reuters Trust Principles.