Phosphorus content in soil, uptake by plants and balance in three Europeanlong-term field experiments

The fate of phosphorus (P) derived from mineral fertilisers and organic man ures, and the effective P balance, have been assessed in three long-term fi eld experiments at Rothamsted (UK), Bad Lauchstaedt (Germany) and Skierniew ice (Poland). This paper discusses the plant availability, uptake and overa ll utilisation of P over the last 30 years, based on soil test P 'availabil ity indices' and crop analyses determined by the standard methods used in e ach of the three countries. The data suggest that differences in soil type significantly influence the dynamics of P at the three locations, but most significantly between a loess Chernozem at Bad Lauchstaedt with a high orga nic matter content and the soils at the other two locations which have a lo w organic matter content. The application of P either as inorganic fertilis er or organic manure had a considerable influence on the availablity, uptak e, leaching or fixing of P, but the crop recovery rate of P from mineral fe rtiliser did not exceed 35% with the smallest recovery (average 18%) occurr ing in the soil with the highest clay content at Rothamsted. At Bad Lauchst aedt and Rothamsted the most efficient utilisation of P (averages of 47% an d 37%, respectively) was from soils treated with farmyard manure (FYM), wit h the greater quantity of P either leached or fixed (8 and 25 kg ha(-1) y(- 1), respectively) occurring in soils treated with superphosphate. At Skiern iewice, however, the reverse was true. Overall, the most efficient crop uti lisation from mineral P (30% average) was from the loamy sand at Skierniewi ce. P balances for the three locations show that quantitatively, for the sa me P input, the amount of P either leached from or fixed in the plough laye r of Broadbalk field, Rothamsted, was 2-3 times greater than at Skierniewic e and 3-6 times greater than at Bad Lauchstaedt. The results suggest that d ifferences in the soil physico-chemical properties, climate, the availabili ty of other major nutrients, and the form in which P is applied, all influe nce the effectiveness of P fertilisation and P balance. The investigation h ighlights the importance of maintaining long-term field experiments and arc hived soil and crop samples on a world-wide basis for understanding nutrien t cycling and fertility dynamics.