Employing fertilizer for farming has a long history dating back 8000 years. In ancient times, manure has been the most logical fertilizer to use. Babylonians, Egyptians, Romans, and early Germans were recorded using minerals or manure to increase yields. The foundation for the modern fertilizer industry was laid by Justus Liebig in 1840, who was concerned with elements needed to plant growth and development. Around 1933 the production of solid ammonium nitrate for fertilizer use began on a significant scale in the United States during World War II. In 1843 Lawes began producing superphosphate of lime. The K fertilizer industry started in Germany in 1861. Rapid boosts given by synthetic fertilizers attracted the farmers. Therefore, demand for synthetic fertilizers increased.