Organic viticulture and soil quality: A long-term study in Southern France

Abstract

a b s t r a c tThe rate of conversion of conventional vineyards into organic farming is currently increasing. This results in modifications of agricultural practices such as the application of organic manure, the use of tillage or grass-cutting to control weeds and the application of natural pesticides with preventive action. One of the aims of organic farming is to preserve the environment. In this context, the objective of our work was to evaluate the long-term effects of organic viticulture on soil quality. The study was conducted in a commercial vineyard where plots which had been organically managed for 7 (Organic7), 11 (Organic11) and 17 years (Organic17) were compared to conventionally managed plots (Conventional). Soil physical and chemical parameters (bulk density, organic matter, available phosphorus, potassium and copper contents) and biological parameters (soil microbial biomass, density of nematode trophic groups and density and biomass of earthworm ecological categories) were measured. The organic farming led to an increase in soil organic matter, potassium content, soil microbial biomass, plant-feeding and fungalfeeding nematode densities. However, organic farming increased soil compaction, decreased endogeic earthworm density and did not modify the soil micro-food web evaluated by nematofauna analysis. Our study highlights the difficulty to show the benefits of organic farming on global soil quality in this particular pedoclimatic area and set of farming practices.

Management of service crops for the provision of ecosystem services in vineyards: A review

“…In contrast, some studies highlight significant increase in SOM content, depending on the service crop species, after only three years (Belmonte et al, 2016;Marques et al, 2010). The service crop biomass production also contributes to the sequestration process but could be limited in case of a reduced dry matter production, because of poor soil quality or unfavourable climate condition for example (Celette et al, 2009;Coll et al, 2011;Salomé et al, 2016).…”

“…Nitrogen nutrition is also an important issue in vineyards: excessive fertilization might lead to an abundant vegetative development, competing with and then impairing berry maturation (Conradie, 2005). Fertilizers (notably organic ones) are thus barely used or non-existent in some wine growing regions (Celette et al, 2009), which can generate very poor soils (Coll et al, 2011;Salomé et al, 2016). Introducing a service crop in vineyards induces competition with the grapevine for water and nutrients.…”

“…Service crops and reduced soil perturbation provide resources that maintain higher trophic levels in soils (Sánchez-Moreno et al, 2009). Additionally, compared to soil tillage, the introduction of service crops and mulches has a positive impact on earthworm abundance and activity (Coll et al, 2011;Peigné et al, 2009;Vrsic, 2011). Schreck et al (2012) also underlined that chemical weeding can favour overall earthworms abundance (non-disturbed soil) but may also decrease the number of specific populations (epi-anecic worms) and cause toxic stress, cellular dysfunction or apoptosis for earthworms.…”

“…Viticulture is one of the most erosion-prone land uses (García-Ruiz, 2010): soils often present poor organic carbon levels (Coll et al, 2011;Salomé et al, 2016), some vineyards are located on steep slopes and shallow soils where heavy rain events generate runoff, and soil tillage exacerbates soil losses (Le Bissonnais and Andrieux, 2007). Such degradation of soil quality may bring serious problem for wine production as soil represents a key component of the concept of terroir (van Leeuwen et al, 2004).…”

Climate change, wine, and conservation

“…Vineyard establishment involves removal of native vegetation, typically followed by deep plowing, fumigation with methyl bromide or other soilsterilizing chemicals, and the application of fertilizers and fungicides (16,17). Mature, producing vineyards have low habitat value for native vertebrates and invertebrates, and are visited more often by nonnative species (18,19).…”