RT Journal Article SR Electronic T1 The Argentinean Pampas: A key region with a negative nutrient balance and soil degradation needs better nutrient management and conservation programs to sustain its future viability as a world agroresource JF Journal of Soil and Water Conservation FD Soil and Water Conservation Society SP 150A OP 153A DO 10.2489/jswc.64.5.150A VO 64 IS 5 A1 Raul S. Lavado A1 Miguel A. Taboada YR 2009 UL http://www.jswconline.org/content/64/5/150A.abstract AB