John William Boniface Sr. bent down and ran his fingers through the grass at his Bonita Farm in Harford County.“Maryland has as good a grass as Kentucky,” he told a group of visitors from South Korea.Boniface boasted that Maryland held its first thoroughbred horse race in 1721, back when Kentucky was still open prairie.“Maryland is the place to buy and breed horses,” he said. “When they tell you all that you’ve got to be in Kentucky, that’s [nonsense].”Boniface is one of a group of Maryland horse industry boosters who’ve spent the week wooing the South Korean horse farm owners and breeders. They’ve been trying to convince the South Koreans to buy Maryland horses — and to build lasting relationships with Maryland’s equestrian industry.That mission, highlighted by Wednesday’s tour of horse farms in Harford County, is part of a larger effort by Maryland officials to bolster economic ties with South Korea. To promote the initiative, they have drawn on the help of Maryland First Lady Yumi Hogan, the South Korean-born wife of Gov. Larry Hogan.It was during a trade mission in September with other Maryland officials that Yumi Hogan convinced South Korea horse owners to come to Maryland to explore the…