Soil sampling occurred in July 2019 in a commercial field situated in Gabbioneta-Binanuova (45°12’03.0” N 10°12’27.8” E), Cremona, Po Valley (Northern Italy). At the selected field site conservation agriculture practices have been adopted since 2011. Specifically: (i) A mixture of cover crops (CCs), composed by rye (Secale cereale L.), hairy vetch (Vicia villosa Roth), and radish (Raphanus sativus L.), was sown each year after harvesting the previous main crop and terminated right before the next seedbed preparation; (ii) reduced-tillage (RT) operations, which consisted of a ripper passage (25 cm depth) and one/two spring harrowing (10–15 cm depth), were annually performed before planting the main crop. The crop sequence was a 3-year crop rotation including maize (Zea mays L.), soybean (Glycine max (L.) Merr.), and processing tomato (Solanum lycopersicum L.).
Soil samples adhered to the roots of tomato plants were manually separated from the surrounding bulk soil and collected. The plants were carefully uprooted from soil, collected in sterile polybags and stored at 4 °C for the isolation of rhizobacteria. The rhizosphere and rhizoplane soil were separated from the bulk soil following the method proposed by Barillot et al. [40 (link)]. Briefly, bulk soil was removed shaking plants by hand for 10 min vigorously, paying attention to the roots’ integrity, as long as the roots’ non-adhering soil particles were completely removed. In order to collect rhizosphere and rhizoplane soil, the root system was washed with 500 mL of 0.9% NaCl added with Tween 80 (0.01% v/v) and afterwards 150 mL of bacterial suspension were incubated at 25 °C for 90 min with shaking at 180 rpm.
Soil samples adhered to the roots of tomato plants were manually separated from the surrounding bulk soil and collected. The plants were carefully uprooted from soil, collected in sterile polybags and stored at 4 °C for the isolation of rhizobacteria. The rhizosphere and rhizoplane soil were separated from the bulk soil following the method proposed by Barillot et al. [40 (link)]. Briefly, bulk soil was removed shaking plants by hand for 10 min vigorously, paying attention to the roots’ integrity, as long as the roots’ non-adhering soil particles were completely removed. In order to collect rhizosphere and rhizoplane soil, the root system was washed with 500 mL of 0.9% NaCl added with Tween 80 (0.01% v/v) and afterwards 150 mL of bacterial suspension were incubated at 25 °C for 90 min with shaking at 180 rpm.
Free full text: Click here
