Estimation of soil mobilization rates by a rainy period and intense tillage practices in vineyards—A case study in the Maule region (Chile)

Abstract

Winemaking in Chile is a long tradition that is recognized around the world. It is especially important in the Maule region where more than 40% of the total wine in the country is produced. However, there is a lack of studies related to soil erosion in vineyards in Chile, especially considering the extreme rainfall events that occur in the country. This research estimates soil erosion mobilization rates before and after a rainy season between April 2020 and May 2020 using the "improved stock unearthing method" on two inter-row plots in a vineyard located in the Maule region of Chile. This method relies on the graft union as a bioindicator for assessing soil surface-level changes. Maps of the soil surface were obtained to show how soil depletion and accumulation points within the inter-row areas could be detected. It has been estimated that a total soil mobilization of 85.7 and 130 Mg ha yr À1 had occurred in the inter-row areas 1 and 2, respectively, since the establishment of the plantation. However, a single rain event mobilized soil at rates of 5.5 and 3.5 Mg ha yr À1 , respectively, in the inter-row areas 1 and 2. We have demonstrated that erosive processes present in the study area exceed the rates of soil formation and the tolerable rates of erosion on a global scale. The results allow re-thinking of agricultural practices and management of soil systems to improve the sustainability of conventional Chilean vineyards and their soils.erosion, improved stock unearthing method, sustainable agriculture, vineyards | INTRODUCTIONGlobally, about a third of the total arable land has been lost in the last 40 years due to erosion, and at an alarming loss rate of more than 10 million ha per year (FAO, 2015). Many recent investigations estimated that cultivated soils show severe or moderate degradation due to the absence of vegetation cover and the use of herbicides (Cerdà,

The Health of Vineyard Soils: Towards a Sustainable Viticulture

“…In the case of viticultural systems, the SOM depletion has been especially severe [123,124] because vineyards have been overall traditionally developed on sloping lands subjected to sustained conventional tillage, thus becoming highly erodible [24,[125][126][127][128]. Indeed, in areas under the Mediterranean climate, i.e., where a good deal of the World's wine growing takes place, soil water erosion in vineyards attains high rates [129] due to the Mediterranean-characteristic intense rainfalls [130,131], evident in remarkable topsoil thinning [123] and even soil truncation [132]. Since SOM is usually highest in the topsoil and exponentially decreases with depth [133][134][135], topsoil thinning and soil truncation mean a severe loss of SOM.…”