The researchers mixed different ratios of feldspathic sandstone and sand to grow crops in the desert and studied how the soil changed over 4 years. They found that after planting crops, the soil with a 1:2 ratio had the highest amount of stable aggregates, which help soil structure. This soil also had the most organic matter, which is good for plant growth. Overall, the 1:2 ratio soil was the best for forming stable aggregates after 4 years of crop planting.