Organic amendments as a source of phosphorus: agronomic and environmental impact of different animal manures applied to an acid soil.

Phosphorus (P) is a non-renewable resource highlighting the significance of developing and using alternative P sources for a sustainable agriculture. The work aims to compare the effects of different organic amendments (OA) and a mineral P fertiliser as reference on P use efficiency by the crop, and on P losses to runoff waters and eroded sediments. A two-year field trial was conducted in a Dystric Regosol withLoliumsp. Treatments were: cattle manure compost (CM), solid fraction of swine (SS) and duck (DS) slurries and triple superphosphate (TSP), each applied at 50 kg P ha−1 year−1. Olsen P (mg P kg−1) increased from ≈ 19 at the beginning to ≈ 30 (TSP, CM), 45 (SS) and 62 (DS) after the experiment. Most of applied P remained in soil, between 92% (SS) and 96% (TSP), plant uptake ranged from 5% (CM) to 3.5% (TSP) and total P loss in runoff and sediments ranged between 0.2% (CM) and 4% (SS). OA increased P-use efficiency by the ryegrass crop compared with mineral P fertilizer. Composted cattle manure showed the best agronomic and environmental behaviour, simultaneously increasing P-use efficiency and decreasing P losses by runoff and erosion. [ABSTRACT FROM AUTHOR]