Effect of seaweed on the levels of available phosphorus and nitrogen in a calcareous soil.

Abstract

The objective of the present investigation was to study changes in levels of phosphorus and nitrogen in soils supplemented with dry, ground seaweeed, KNO3, and KH2PO4. After intervals of 21, 42, 76 and 105 days, phosphorus, nitrate, and ammonium were determined. The results showed that the seaweed affected the status of total inorganic N and P in the soil. In all systems the levels of available inorganic phosphorus increased. However, part of the N that was added as nitrate or that was originally present in the soil was immobilized. The results further indicated that inorganic P of seaweed origin was probably in a form other than simple phosphate.