NUTRIENT AND ELEMENT EXPORT IS AFFECTED BY WIND SORTING IN DIFFERENT TEXTURED AGRICULTURAL SOILS

LAURA ANTONELA ITURRI; ROGER FUNK; MICHAEL SOMMER; DANIEL EDUARDO BUSCHIAZZO

Bordeaux

Congreso; X Internation Conference on Aeolian Research; 2018

ISAR

The elements in the sediments transported during a wind erosion event can show different trends in their distribution in height, affecting their export at the field or regional scale. Those nutrients and elements that are present in coarse aggregate compounds are transported by saltation, remaining at low heights across short distances, while those in low-density compounds, by suspension, at great heights and long distances. In different texture soils, these trends can be affected by wind sorting. The aim of this study was to evaluate how sorting caused by the wind could influence the nutrient and element exportation in different textured soils from the Semiarid Pampean Region of Argentina.For that reason, the 2.5 uppermost-cm of two soils, a sandy Typic Ustipsamment and a loamy Entic Haplustoll, were used for wind tunnel simulations. The sediments transported by saltation were collected with BSNE samplers at heights of 0.05, 0.17, 0.32 and 0.48 m. The particulate matter (PM10) was obtained with a dust collector (EDG [1]). The soils, the sediments collected at different heights and the PM10 were analyzed for C, N, P and S by dry combustion using an elemental analyzer, and Ca, Mg, K, Na, Fe, Al, Mn, Ba, Cu, Zn, Ag, Be, Cd, Cu, Cr by ICP-OES. All elements were more abundant in the bulk soils, the saltation fraction and the PM10 of the loamy soil. C and N were associated mainly with organic compounds and particles of lower density, as well as P, Al and Zn to clays; also S, but only in the coarse soil. P, Ca, Mg, K, Na were present in high-density coarse size particles, due to their presence in apatite and feldspars minerals dominating coarse silt and fine sands and as part of aggregates. Ba and Mn increased their content as well as height increased in the coarse soils although they showed the opposite trend in the loamy. Cu did not show a define accumulation pattern in variable density and size particles. Ag, Be, Cd, Cu and Cr were detected neither in the bulk soils nor in their saltating and particulate material. Because of that, the nutrients and elements transported in high-density particles or aggregates by saltation can affect their losses-deposition balance at field scale, while those transported by suspension in low-density compounds can be exported at longer distances influencing regional or global scale process, like C sequestration. Moreover, as the sandy soils experienced a separation between mineral and organic particles in height more intensive than in fine soils [2], the nutrient exportation process by suspension would be more intense in coarser soils.