The study looked at different ways of growing crops in a specific type of soil to see how well they balanced nutrients like nitrogen, phosphorus, and potassium. They found that the system with rice followed by green manure had the most nitrogen left over, while the system with rice followed by rape had the biggest nitrogen deficit. All systems lacked enough phosphorus and potassium, but the rice-rice-rape system had the largest deficiencies. Returning organic matter to the soil was best in the rice-rice-green manure system, helping build up nutrients, while the rice-rice system had the least organic matter returned and had a negative impact on nutrient balance.