Estudio de la capacidad de retención de fósforo de suelos representativos de la región Pampa Ondulada (Buenos Aires), frente al agregado de altas cargas de estiércol bovino

Abstract

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.