The study looked at how different ways of tilling and managing weeds affect soil water and organic carbon in a winter wheat field. They found that keeping some weeds can help save water in the soil, especially during certain stages of wheat growth. However, removing weeds can lead to higher grain yields, especially when using subsoil tillage. Overall, keeping weeds increased soil organic carbon at the jointing stage but decreased it at later stages. Rotary tillage gave the highest grain yield when keeping weeds, while conventional tillage gave the lowest.