The study looked at the levels of phosphorus in the soil around Amorpha fruticosa plants of different ages. They found that the soil near the roots had more available phosphorus than the soil further away. The oldest plants had the highest inorganic phosphorus content. Certain phosphorus fractions were higher in the soil near the roots compared to the bulk soil. The levels of available phosphorus in the soil near the roots were related to specific phosphorus fractions. Overall, the available phosphorus and pH levels near the roots did not have a significant relationship with the total phosphorus levels in the soil near the roots.