Changes in soil phosphorus balance and phosphorus-use efficiency under long-term fertilization conducted on agriculturally used Chernozem in Germany

摘要

This study investigates changes in soil phosphorus (P) in different fertilization treatments applied since 1902 on Chernozem soil at a "Static Fertilization Experiment" in Germany. Total and plant-available soil P, and soil P balances were assessed at 0-30, 30-60, and 60-90 cm depth layers in unfertilized "Zero", mineral "NK" and "NPK", and combined mineral and organic "FYM + NK" (farmyard manure + NK) and "FYM + NPK" fertilization treatments. P-use efficiencies were determined for each crop in rotation (sugar beet, spring barley, potato, and winter wheat). The 110 yr of P fertilization at rates between 22 and 55 t ha(-1) yr(-1) resulted in a significant increase of available P contents. P stocks increased up to 60 cm depth. Total P accumulation comprised 1.4 t ha(-1) for NPK, 1.3 t ha(-1) for FYM + NK, and 3.1 t ha(-1) for FYM + NPK. Crops cultivation without P fertilization in Zero and NK treatments resulted in negative P balances and reduction of available P below recommended levels. Reduction of mineral P application rates after 1981, along with crop variety-dependent yield increases, resulted in an improved P-use efficiency. An organic fertilization combined with mineral N and K fertilizers (FYM + NK) was found to be the most P-efficient treatment for Chernozem soils.