[en] Intensive beef cattle production in feedlots generates large volumes of organic waste, that when deposited directly on the soil can produce nutrient mobilization, such as phosphates (P), towards water resources causing potential effects of eutrophication. One alternative to prevent the entry, accumulation and mobilization of this nutrient in the environment and to avoid it from entering water resources is to deposit organic waste in areas prepared for this purpose. However, Argentina still does not have specific regulations that dictate the required properties of the soils to be used as a floor in the storage of manure (solid or liquid). For this reason, it is necessary to obtain regional data that demonstrates the vulnerability of the soil to the mobility of this nutrient. The aim of this work was to study the P retention capacity on representative types of soil with argillic horizon of the Rolling Pampas region, when faced with the aggregate of high amounts of cattle manure, and its relationship with the edaphic and climatic variables of the region. One of these soils, affected by different areas in a feedlot: a solid manure storage area, a liquid manure storage area, and a Control area (without manure), was analyzed. In each of these areas, samples were taken in depth to characterize the dynamic and the accumulated mass amount of P, the soil variables related to them and the degree of P saturation (DPS). A vertical movement of this nutrient was observed when the DPS threshold was exceeded. To analyze the effect of soil and weather properties on the potential phosphorus movement through subsurface flow in four soils of the region, simulation models were also performed. As a result, the soils showed high P retention capacity in the solid manure storage areas, but low and variable capacity in the liquid manure storage areas.

[gl] A produción intensiva de gando bovino xera grandes volumes de residuos biolóxicos, que cando se eliminan directamente no solo, poden producir a mobilización de nutrientes, como os fosfatos (P), cara aos recursos hídricos, xerando potenciais efectos de eutrofización. Unha das alternativas para evitar que este nutriente entre, se acumule, se mobilice e chegue aos recursos hídricos é depositar os residuos nas zonas preparadas para este fin. Emporiso, Arxentina aínda non dispón de regulacións específicas que indiquen as propiedades que deben cumprir os solos para poder utilizarse como chan na acumulación de esterco (sólido ou líquido). Por iso, é necesario obter datos rexionais que mostren a vulnerabilidade dos solos á mobilidade deste nutriente. O obxectivo deste traballo foi estudar a capacidade de retención de fósforo dos solos cun horizonte arxílico, representativos da Pampa Ondulada, en comparación coa adición de altas cargas de esterco bovino, e a súa relación coas variables edáficas e climáticas da rexión. Por unha banda, analizouse un solo nun establecemento de engorde en curral, afectado por distintas zonas: zona de acumulación de esterco sólido, zona de almacenamento de esterco líquido, zona de control (sen esterco). En cada un destes sitios tomáronse mostras en profundidade para caracterizar a dinámica e a masa do P acumulado, as propiedades edáficas relacionadas con eles e o grao de saturación (GSP). Observouse a migración vertical do nutriente cando se superou o límite do GSP. Por outra banda, o efecto das características dos solos e do clima no potencial perda do fosfato por fluxo subterráneo en catro solos da rexión analizouse mediante modelos de simulación. Así, os solos mostraron unha alta capacidade de retención deste nutriente nas áreas de almacenamento de esterco sólido, pero baixa e variable nas áreas de almacenamento de esterco líquido.