The scientists tested different materials to stop water loss and salt buildup in salty coastal soil. They buried layers of corn straw, biochar, and peat at 20 cm deep. Biochar helped keep more water in the soil but didn't stop salt buildup well. Corn straw and peat layers were best at stopping salt buildup, reducing it by 96% and 93%. However, the straw layer kept too much water from evaporating, while the peat layer kept more water in the soil. So, burying a 6-cm-thick peat layer is the best way to keep water in the top soil and stop salt from building up in deeper soil.