 He then implemented the "tuntian" policy to create a new source of food supply, by ordering his troops to grow crops on the south bank of the Wei River alongside the civilians living in the area.He also forbade his troops from taking the civilians' crops.The Wei emperor Cao Rui became worried and sent General Qin Lang with 20,000 infantry and cavalry to the Guanzhong region to join Sima Yi, the Grand Chief Controller () of the Wei military forces in the region.