A study looked at different ways of tilling and managing crop residue on a farm in Hebei province. They found that using less tillage or no tillage didn't affect crop yield at first, but after a few years, wheat yield decreased by almost 32%. This was likely due to soil becoming denser, colder, and lacking nutrients. However, continuous no tillage didn't have a big impact on corn yield. Deep tillage didn't increase crop yield. Mulching crop residue sometimes hindered wheat growth. No tillage increased soil organic matter and total nitrogen but decreased available nitrogen.