SALINITY CHANGES IN IRRIGATED AND NON IRRIGATED SOILS WITHIN MENDOZA RIVER IRRIGATED AREA José Morábito (1,2), Carlos Mirábile (1), Miguel Manzanera (1), Osvaldo Cappe (2), Diego Tozzi (1) y Leandro Mastrantonio (2) Instituto Nacional del Agua – Centro Regional Andino (1) Universidad Nacional de Cuyo – Facultad de Ciencias Agrarias (2) Mendoza, Argentina Presented by J. Perez Peña

INTRODUCTION North Oasis of Mendoza Annual Rainfal 200 mm Irrigated by Mendoza River and Tunuyán River Most of the Mendoza population Water Uses: potable water, agriculture, recreation, power generation, others. Main agriculture crops: grape, stone fruit trees, fruit trees (peaches, plumbs, appricots, sweet cherries, pears, apples, quincy) and vegetables (garlic, onions, tomatoes and potatoes) Irrigated Area in Argentina 1.6 M ha Irrigation Water70% de toda la extracción Irrigation efficiency40%

Surface irrigation Drip irrigationBoth?

MAIN GOALS Evaluate changes in soil salinity with time of cultivated and non cultivated soils in the area of Mendoza River Identify subareas with increasing or decreasing salinity level Provide basic information in order to design strategies of recovering affected soils by improving the natural or artificial drainage system or building new drainage canals Provide general information for those responsible for water use and distribution in order to maintain a salinity balance in the irrigated area

MATERIALES Y MÉTODOS Main Measured Variable Electric conductivity (Ce es [mS cm ºC]) at 0-50 and cm soil depth Year 1973 Year 2002 Irrigated Non Irrigated (“Comité Conjunto de Mendoza - Agua y Energía Eléctrica, Consorcio Potrerillos”, 1975) Coordenadas y salinidad del extracto de saturación de 2002 (Morábito et al., 2004). Results and data collected were displayed on maps and analyzed according to soil status and soil depth Non irrigated in Mendoza is the same as saying non cultivated

Este Mendocino South Region Uco Valley North Region High Area of Mendoza River East Region MENDOZA VITICULTURE AREAS

Sampling locations in the North Oasis Mendoza River Tunuyan River

Frequency Histograms for EC es (μS cm -1 ) soil depth 0 a 50 cm Non irrigated Area 1973Irrigated Area 1973 Irrigated Area 2002 Non irrigated Area 2002

RESULTS Valores de probabilidad y significancia de la prueba de Kruskal-Wallis, dentro y entre grupos, y para cada profundidad de muestreo Nota: *=significativo y ns=no significativo, para =0,05 Comparison between irrigated and non Irrigated and between years

Salinity differences in non irrigated soils for the 0-50 cm soil depth in Mendoza River area ( ) Areas where salinity decreased Areas where salinity increased RESULTS

Areas where salinity decreased Salinity differences in irrigated soils for the 0-50 cm soil depth in Mendoza River area ( ) Areas where salinity increased RESULTS

CONCLUSIONS Significant differences in EC es between cultivated and non cultivated soil No differences in ECes between 1973 and 2002 Irrigated areas have maintained a salinity balance within the soil probably due to low irrigation efficiencies that contributed to fulfill the leaching fraction required If irrigation efficiencies increase, the scenario presented here can be different and therefore this kind of study must be repeated in the future