P removal by reed harvest in the Kis-Balaton reservoir - dream or reality?

Soluble reactive P (SRP) load of the Lower Kis-Balaton Reservoir varied bet ween 1.27-4.85 t yr(-1). This load did not decrease while passing the 16 km (2) reed area. On the contrary, the outflow load of 3.53-25.64 t yr(-1) exc eeded the inflow. According to the original conception, reed stands should have retained most of the P load. We followed seasonal changes in the bioma ss and P content of reed shoots and rhizomes. We measured P uptake or relea se by the reed from/into the water. Plants covered 70% of the shootis P dem and from the P pool of the rhizomes, and took up the rest from the soil. We conclude that reed harvest will not improve P retention of the Reservoir.