Effects of Organic Mulches on the Soil Temperature, Humidity and CO2 Emissions

Abstract

A large portion of the world wine production is located in regions suffering - or expected to suffer - from desertification. These agricultural soils, in addition to being highly unstructured, have very low levels of organic matter (<1%). This is aggravated by an abusive tillage of the plots, which implies that the maintenance of these soils depends entirely on the addition of chemical products such as fertilizers and herbicides. This situation, in turn, leads to physiological imbalances in the vine that result in deficiencies in the quality of the grape. In viticulture, the development of regenerative techniques to improve soil quality is aimed at benefiting producers, and specifically at improving the productivity, sustainability and biodiversity of their soils, as well as adapting their production systems to the new climate change scenarios (response to abiotic stresses - extreme temperature, water stress -). Organic mulch is an effective method to manipulate the crop-growing microclimate increasing crop yield by controlling soil temperature and retaining soil moisture by reducing soil evaporation. Moreover, carbon dioxide (CO2) emissions are also mitigated by this practice. The effectiveness of different organic mulching materials applied within the row of a vineyard was evaluated in a Tempranillo vineyard located in La Rioja (Spain). Organic mulches (straw mulch, SM; grapevine pruning debris, GPD and spent mushroom compost, SMC) were compared with two traditional bare soil management techniques (one based on the use of herbicides to avoid weed incidence and one based on the use of the tillage inter-row). Keywords: Mulching, bare soil; Soil moisture; Soil temperature, CO2 respiration Abbreviations: SM: Straw Mulch; GPD: Grapevine Pruning Debris; SMC: Spent Mushroom Compost