Boise-based Simplot will close a manufacturing plant in California, and separately close a number of its Simplot Grower Solutions locations. The company announced last year it would shut down its plant in Lathrop, California. The plant is part Company’s Mining & Manufacturing division and makes fertilizer, feed phosphates and industrial products. According to BoiseDev, the Lathrop plant will close by the end of the month, and 150 positions will be eliminated.