SALINITY CHANGES IN IRRIGATED AND NON IRRIGATED SOILS

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 Irrigated Area in Argentina Irrigation Water Irrigation efficiency 1. 6 M ha 70% de toda la extracción 40% 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)

Surface irrigation Drip irrigation Both?

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 (Cees [m. S cm-1 25 ºC]) at 0 -50 and 50 -100 cm soil depth Year 1973 Year 2002 Irrigated 127 173 Non Irrigated 61 38 Non irrigated in Mendoza is the same as saying non cultivated 1973 (“Comité Conjunto de Mendoza - Agua y Energía Eléctrica, Consorcio Potrerillos”, 1975). 2002 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

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

Sampling locations in the North Oasis Mendoza River Tunuyan River

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

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

RESULTS Areas where salinity decreased Salinity differences in non irrigated soils for the 0 -50 cm soil depth in Mendoza River area (2002 -1973) 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 (2002 -1973) Areas where salinity increased

CONCLUSIONS Significant differences in ECes 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 h can be different and therefore this kind of study must be repeated in the future