Researchers assessed how effective leftover phosphate is in different soils by using a special method. They added phosphate to soils and let them sit at different temperatures for a year. Then, they measured how much phosphate was still available. They found that higher temperatures led to less available phosphate. The type of soil and its properties like pH, organic matter, and calcium carbonate affected how much phosphate remained. As time passed, the amount of available phosphate decreased. Overall, the effectiveness of leftover phosphate varies depending on the soil type, and time and temperature play a big role in how much is left in the soil.