Improving the Sustainability of Tomato Production With Biochar and Biofertilizers in Emilia‐Romagna, Italy

ABSTRACT Conventional agriculture is mainly dependent on chemistry and energy to promote growth and yield and on pesticides to protect crops from pests or pathogens. Biofertilizers as plant growth‐promoting microbes (PGPM) and novel soil amendments, as biochar, are considered sustainable alternatives to diminish the excessive use of chemicals in agriculture. The effects of biochar, whether used alone or in combination with biofertilizers, are still not fully understood, and its potential benefits have yet to be thoroughly investigated. Additional field studies across various agronomic conditions are needed to confirm the impact of biochar–microbial consortia before they can be widely adopted in sustainable agricultural practices. Industrial tomato is a paradigmatic example of a culture requiring resources as well as fertilisers and energy. Results from field trials performed in two different locations in Emilia‐Romagna (Italy): Parma and Ferrara (two different fields), with both conventional and organic practices, are here reported. Biochar, PGPM and arbuscular mycorrhizal fungi (AMF) were applied in field trials for two to three consecutive years. Soil characteristics, both chemical and biological, revealed that the fields had features comparable to the average European arable soils; specifically, the rhizospheric biological diversity indexes were similar in the three locations. The most interesting results were obtained in the Parma field location, where it was observed that biochar and PGPM treatment determined a reduction in the number of not ripe fruits (average 65%). When biochar was combined with newly developed PGPM in the two conventional fields, the value of commercial production and the Brix index of the harvest increased. The biofertilizers, when combined with biochar, remarkably permitted saving 20% of chemical fertilisers with a consequent saving in greenhouse gas (GHG) emissions. These results were also considered from an economic perspective, which revealed that PGPM and biochar increase the gross margins while reducing the environmental impact of the tomato cultivation.