**2. Materials and Methods**

The study was performed in a Mediterranean soil ecosystem in Puglia region, Italy (Figure 1) (Turi, located at 40◦91' N, 17◦04´ E, altitude of 247 m above the average of sea level, with long-term annual precipitation range from approximately 550 mm to 600 mm and annual temperature range from 4 to 30 ◦C) with Mediterranean climate conditions according to the Domarten classification.

**Figure 1.** The area located at Turi in Puglia region, Southern Italy.

Three land-use intensities, namely cereal field (winter wheat), grass-covered vineyard, and cherry farm plots, were compared in adjacent plots. The land use descriptions and management are presented in Table 1.


**Table 1.** Land use management.

The area was a natural landform with carbonates, clay, and iron oxides accumulation in depth (Chromic and Calcic Luvisols) that has been converted to farmland by rock fragmentation and intensive agricultural practices about 10 years ago and cultivated continuously. The geological characteristics of the plots (Luvisols from limestone) are similar and typical for this region.

Three composite soil samples from each land use were taken randomly from the upper soil layer in June 2018. A minimum of five sub-samples were collected, mixed together on site and considered as a composite soil sample. Samplings were carried out at depth of 0–20 cm, since the maximum microbial biomass is devoted to the upper soil horizons [15] and microbial activity is sensitive to changed land uses [16]. The fraction passing a 2 mm sieve was transported refrigerated at 4 ◦C.

## *2.1. Measurements*

Soil pH was measured in an aqueous matrix in 1:2.5 soil: water suspension [17] using pH meter (XS Instruments pH 50, Carpi, Italy), soil texture according to the USDA classification [18] by the relative amounts of sand, silt, and clay in the fine earth fraction includes all soil particles that are less than 2 mm. The Walkley and Black [19] method was performed to measure total soil organic carbon (SOC) and the van Bemmelen factor (=1.724) was used to calculate the amount of soil organic matter (SOM) with the following equation [20]:

$$\text{SOM} = \text{SOC} \times 1.724 \tag{1}$$
