Farming system and sources of organic matter: influence on soil health, yield, and head quality of globe artichoke

Organic farming systems contribute to enhance food security and agricultural sustainability. with the potential to increase farmer's income when external input costs are reduced. Two experiments were conducted to evaluate the influence of organic farming on soil quality (respiration-CO2), yield and head quality (chlorogenic acid and cynarin concentration) of globe artichoke (Cynara cardunculus). Both experiments were conducted over two growing seasons, October 2014 to June 2016. In the first experiment, we compared organic and conventional farming systems while organic matter fertilizer source (plant- vs. animal-based) evaluation was considered in the second experiment. For the first experiment, eight cultivars were used; 'Deserto', 'Lulu', 'Romolo', '11-018', '12-179', 'Green Globe Improved' and 'Imperial Star'. The cultivar '12-179' was used for the second study in order to screen plant-based (alfalfa meal) and animal-based (fish meal, blood meal, and chicken manure) fertilizers for soil health, yield and head quality. Conventional farming had higher plant marketable yield compared to organic. Conversely, artichoke head from organic farming had 31% chlorogenic acid and 12% cynarin higher than conventional system. Interestingly, organic farming improved the soil health indicator (respiration-CO2) by 20-fold compared to conventional. Although cultivar response to soil farming system treatments was inconsistent across the study period (2015-2016), 'Imperial Star' had the lowest marketable yield and head quality. After two years of organic soil amended with animal-based fertilizers, marketable yield was higher than soil amended with plant-based fertilizer. However, alfalfa meal (plant-based) organic fertilizer increased soil respiration by about 3.5-fold compared to animal-based (fish meal, blood meal, and chicken manure) organic fertilizers at the end of the experiment. In addition, concentrations of phytochemicals (chlorogenic acid and cynarin) in artichoke heads grown in soil amended with alfalfa meal were higher than in those grown with animal-based fertilizers.