Distribuzione del carbonio organico e dell’azoto in pereti biologici e convenzionali dell’Emilia-Romagna

A survey of the role of organic vs. conventional on soil C sink/source was performed in 2007 in 8 typical organic vs. 8 conventional peach orchard farms located in Emilia-Romagna Region, Italy. Chemical analyses were carried out on top layer (0-15 cm depth). Determination included total (TOC), extracted (TEC) and humified (HA+FA) organic carbon, total nitrogen (TN) and isotopic signatures δ 13C and δ 15N. Principal component analysis (PCA) was carried using the following variables: TOC, TN, C/N, δ 13C, δ 15N. Conventional peach orchards showed lower values of all the parameters compared vs. organic orchards. PCA analysis has shown that in organic farms δ 13C and 15N are positively correlated with TOC and TN and δ 13C can be used for further discrimination concerning the type of fertilizer used. From the quantitative point of view an average increasing of TOC and HA+FA of 15.5 and 18.5%, respectively, was observed.