Start of the show
Many officials were interested when they heard that Su Wan knew how to grow vegetables without soil. They had after all never heard such a thing before and wanted to get more of the inside information but of course, Lord Yan was no fool, he did not tell them anything and played coy saying that he too was unaware of the matter and only knew the surface knowledge.
Did they think that he was an idiot, who would tell them everything? He knew that these nobles wanted to grab hold of the formula and then present it as their own such that they could climb up the ranks as well. He was not an idiot to drop an axe on his foot, thus Lord Yan did not say a word about how the soilless vegetables could be grown.