The study looked at how using recycled chicken manure and spent mushroom substrate can improve sandy soils for farming. By adding these materials every 1-2 years for 20 years, the soil's organic matter increased significantly, especially near the surface. The pH levels also improved, making the soil less acidic. Water retention capacity increased with chicken manure, while spent mushroom substrate helped retain water at different depths. Both materials changed the soil's pore structure, affecting how water moves through it. Overall, using these recycled materials can help increase soil quality, water retention, and crop productivity in sandy, acidic soils.