Effect of superphosphate on the retention of phosphorus by peat soil

Authors

• Armi Kaila University of Helsinki, Department of Agricultural Chemistry

DOI: https://doi.org/10.23986/afsci.71495

Abstract

The phosphate retention by peat samples from a field trial in which superphosphate has been for 34 years applied at annual rates of 0, 100, 200, and 300 kg/ha, respectively, was studied. It was found by various methods that the samples from the plots of the higher treatments were able to sorb more phosphate than were the samples from the untreated plots and the soil with the lowest phosphate application. The higher content of iron and aluminum in the soils of the higher treatments probably accounts for their higher capacity to retain phosphate. It is possible that in clayed peat soil the higher content of exchangeable calcium and the lower acidity of the samples of the higher treatments are able to increase the effect of aluminum. The factors which are responsible for the differences in the iron and aluminum contents of the variously treated plots are discussed. It is unlikely that these results would be of importance under practical conditions.