The researchers studied how using organic materials like farmyard manure, wheat straw, and green manure along with fertilizers affected soil and crop growth over 22 cycles of pearl millet and wheat. They found that adding organic materials to fertilizers increased soil health by raising organic carbon levels, improving nutrient availability, and boosting wheat yields. Farmyard manure was the most effective at increasing soil organic carbon and nutrient levels. Overall, using a combination of organic materials and fertilizers improved soil quality, leading to higher crop productivity in the pearl millet-wheat cropping system.