country's total GDP, although the sector employs about one-eighth of the total labour force. It has the world's third-largest cultivated area, at . However, due to the harshness of its environment, about 13.1% of its land is agricultural, and only 7.4% of its land is arable. The country's agricultural land is considered part of the "breadbasket" of Europe. More than one-third of the sown area is devoted to fodder crops, and the remaining farmland is devoted to industrial crops, vegetables, and fruits. The main product of Russian farming has always been grain, which occupies considerably more than half of the cropland. Russia is the world's largest exporter of wheat, the largest producer of barley and buckwheat, among the largest exporters of maize and sunflower oil, and the leading producer of fertilizer. Various analysts of climate change adaptation foresee large opportunities for Russian agriculture during the rest of the 21st century as arability increases in Siberia, which would lead to both internal and external migration to the region. Owing to its large coastline along three oceans and twelve marginal seas, Russia maintains the world's sixth-largest fishing industry; capturing nearly 5 million tons of fish in 2018. It is home to the world's finest caviar, the beluga; and produces about one-third of all canned fish, and some one-fourth of the world's total fresh and frozen fish. Science and technology Russia spent about 1% of its GDP on research and development in 2019, with the world's tenth-highest budget. It also ranked tenth worldwide in the number of scientific publications in 2020, with roughly 1.3 million papers. Since 1904, Nobel Prize were awarded to 26 Soviets and Russians in physics, chemistry, medicine, economy, literature and peace. Russia ranked 45th in the Global Innovation Index in 2021. Mikhail Lomonosov proposed the conservation of mass in chemical reactions, discovered the atmosphere of Venus, and founded modern geology. Since the times of Nikolay Lobachevsky, who pioneered the non-Euclidean geometry, and Pafnuty Chebyshev, a prominent tutor; Russian mathematicians became among the world's most influential. Dmitry Mendeleev invented the Periodic table, the main framework of modern chemistry. Sofya Kovalevskaya was a pioneer among women in mathematics in the 19th century. Nine Soviet and Russian mathematicians have been awarded with the Fields Medal. Grigori Perelman was offered the first ever Clay Millennium Prize Problems Award for his final proof of the Poincaré conjecture in 2002, as well as the Fields