Union Home Minister Amit Shah on Thursday termed chemical fertilisers as the root cause of many diseases and made a strong pitch for natural farming, saying it not only increases farmers' income but also saves water and promotes public health. Addressing a Farmers' Conference held here, Shah said the government was developing a "complete system" - from soil and laboratory testing, certification to packaging - to ensure that the agricultural produce of the country's farmers reaches global level in a better way as there is a huge market for natural farming in the world. "Chemical fertilisers are the root cause of many diseases today. Natural farming is an approach that doesn't reduce farmers' income, but instead makes their produce pure," he said. Natural farming is a traditional practice that people have forgotten over the time. A dung and urine of a single indigenous cow can help cultivate 21 acres of land, he said. "It (natural farming) increases income, saves water, and relieves