Nutrien did not disclose financial terms of the deal, but said the acquisition multiple was in line with similar sized "tuck-in acquisitions" in North America in recent years.
The Saskatoon, Saskatchewan-based Canadian conglomerate said Agrosema had annual sales of US$60 million across 12 farm centres, with about 200 employees.
Nutrien Ag Solutions has two main operations in Brazil, with a central fertiliser blending facility in Itapetininga and six further facilities in the states of Sao Paulo and Minas Gerais. Nutrien also owns Agrichem which produces specialty liquid fertilisers.
"The Agrosema acquisition is an excellent fit as we continue to build our Ag retail business in the important and growing Brazilian agricultural market," Nutrien CEO Chuck Magro said.
"We expect to continue to expand our operations in Brazil in the coming years, both through acquisition and expansion of product and service offerings."
The company said the Agrosema acquisition would add a new market channel for the company's product line-up.
Closing of the transaction is subject to approval by the Brazil competition regulator known as the Administrative Council for Economic Defence, and customary closing conditions.
Nutrien shares trading in Toronto (TSX:NTR) closed up nearly 1% Monday at C$61.35, after touching a new 12-month low at $60.22 on the back of the acquisition announcement. It has a current market capitalisation of $35 billion (US$27 billion).