The researchers studied how adding boron to sandy soil affects sunflower growth. They tested different levels of boron in pot experiments over two years. They found that adding boron didn't improve sunflower kernel weight or oil and protein content. High boron levels caused leaf damage and decreased kernel weight. The amount of boron in the kernels didn't increase with more boron in the soil. A small amount of boron was enough for the sunflowers. Adding boron didn't affect the plant's other nutrient levels. The soil kept some boron even after adding more.