Water use in rain-fed farming at different scales in the Pampas of Argentina

Abstract

Water use in farming will be an issue of increasing global concern since competition for freshwater among sectors will grow, especially in a water-scarce scenario. Understanding how farming system configurations at different scales affect the partitioning of annual rainfall between production and losses is essential to manage water in rain-fed farming. Data from 198 commercial farms in the Pampas of Argentina were analyzed to assess water use at four different scales: (a) plot, (b) farm, (c) agro-ecological area and (d) whole region. This study offers a novel cross-scale approach and an analytical tool to evaluate water-use relationships in the study region beyond the classical plant-soil-water relationships. Results showed that cattle activities require more water than crops at the plot scale but at broader ones water use patterns are determined largely by cultivation. Given the different performance across scales, results suggest that complex spatial interactions and emerging properties can arise when the analyses are scaled-up from the plot to the regional level. The detection of scale-dependent properties regarding water use will enhance the value of information and knowledge that decision makers operating at different scales need.