Soil organic matter accumulation in vineyards as a function of cultivar and parent material

Claudio Zaccone,Sara Elena Goldoni,Cesar Plaza,Beatrice Giannetta,Giorgio Galluzzi

doi:10.5194/egusphere-egu22-8199

Abstract

&lt;p&gt;The aim of this work was to understand of how parent material and plant cultivar interactively control soil organic matter (SOM) accumulation and stabilization in vineyards.&lt;/p&gt;&lt;p&gt;Three experimental vineyards located in the Valpolicella area (North of Italy) were investigated. These sites were very close each other and, consequently, characterized by the same climatic conditions; at the same time, the corresponding soils developed from completely different parent materials (volcanic &lt;em&gt;vs.&lt;/em&gt; calcareous). Two autochthonous grapevine (&lt;em&gt;Vitis vinifera&lt;/em&gt;&amp;#160;L.) cultivars, planted in 2003 and grown in organic system (no fertilization), were selected in all sites, and the corresponding soils sampled in triplicate with a 10-cm depth resolution. An uncultivated soil profile for each site was used as a control.&lt;/p&gt;&lt;p&gt;Soil samples (n. 88) were characterized for pH, EC, bulk density, total organic C (TOC), total N (TN), texture and major and trace elements. Moreover, particulate organic matter (POM) and mineral associated organic matter (MAOM) fractions were isolated and characterized by elemental analysis (CHNS).&lt;/p&gt;&lt;p&gt;Control soils showed different organic C stocks, ranging from 27 in the volcanic soil with a loamy sand texture to 90 t/ha in the two calcareous soils with a clay texture. A similar trend was observed for TN, ranging from 2 in the volcanic soil to 9 t/ha in the calcareous soils. Moreover, 2/3 of TOC were recovered as MAOM in both clay soils, whereas POM was the main fraction in the volcanic, loamy sand soils.&lt;/p&gt;&lt;p&gt;The cultivation of grapevine affected SOM accumulation. In particular, an increase (1.3-1.5&amp;#215;) of both TOC and TN in the top 30 cm of soil was observed in 2 out of 3 sites, while an opposite trend (0.7&amp;#215;) was recorded in one site. Preliminary data suggest that SOM accumulation is promoted in vineyard soils with lower organic C contents (and a wide range of texture) and through different mechanisms, whereas the cultivar factor did not affect TOC and TN stocks.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Acknowledgements&lt;/p&gt;&lt;p&gt;CZ thanks the Cantina Valpolicella Negrar for allowing soil sampling in its experimental vineyards.&lt;/p&gt;

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