The effect of different fertilization on content of available and unstable phospo-rus in soil

摘要

From the results is clear, that sewage sludges are very important fertiliser from the point of view amount of phosphorus in soil. P amount in soils, and so in both monitored forms ( unstable and available ) strongly raised after their application. It was found almost the same amount of P in treatments NPK and manure 1. The values reached with used methods showed very close correlation. Amount of available phosphorus in soil is lower than amount of unstable P ( by the Mehlich Ⅲ method by 73 % and by Doppel-lactat method by 80% ). With Mehlich Ⅲ method was always found lower contents of phosphorus in soil as with Doppel-lactat method. Values of phosphorus in soil ranged from 101 to 238 mg.kg~(-1) by Mehlich Ⅲ method, from 54 to 210 mg.kg~(-1) by Doppel-lactat and from 344 to 828 mg.kg~(-1) by extracts in ammonium oxalate (c=0, 2 mol.l~(-1)).