The study looked at how plants growing in dry areas affect the amount of carbon and nitrogen in different soil particles. They found that as plants grow, the soil becomes finer and richer in organic matter. After 20 years, the soil texture improved, leading to more carbon and nitrogen being stored in the soil. Sand grains in the soil were negatively related to carbon and nitrogen levels, while silt and clay were positively related. This means that as the soil becomes finer, it can hold more carbon and nitrogen, which is good for the environment.