The Battle of Grand Gulf was fought on April 29, 1863, during th: The agriculture industry is intensive, highly mechanised and efficient by European standards, producing about 60 per cent of food needs with less than 1.6 per cent of the labour force (535,000 workers).[273] Around two-thirds of production is devoted to livestock, one-third to arable crops. The UK retains a significant, though much reduced fishing industry. It is also rich in a variety of natural resources including coal, petroleum, natural gas, tin, limestone, iron ore, salt, clay, chalk, gypsum, lead, silica and an abundance of arable land.[274]