Table 1. Bacterial and fungal α-diversity indices in rhizosphere and non-rhizosphere soil.

Microbial community	Soil sample	Consecutive monoculturing spans	Coverage	Chao 1	Shannon
Bacteria	Rhizosphere Soil	12 y	96.49 ± 0.24 a	4930.32 ± 421.96 ab	6.72 ± 0.40 a
		18 y	96.36 ± 0.22 a	5248.75 ± 349.74 a	7.09 ± 0.16 a
		28 y	97.10 ± 1.30 a	4756.31 ± 269.36 abc	6.82 ± 0.22 a
		38 y	96.65 ± 0.21 a	4676.70 ± 376.47 abc	6.59 ± 0.26 a
	Non-rhizosphere Soil	12 y	97.33 ± 0.93 a	3854.48 ± 255.05 cd	5.92 ± 0.95 a
		18 y	96.55 ± 0.50 a	4143.82 ± 184.53 bcd	6.63 ± 0.39 a
		28 y	98.01 ± 0.93 a	3502.97 ± 482.39 d	6.22 ± 0.08 a
		38 y	97.49 ± 0.45 a	3620.26 ± 360.17 d	6.06 ± 0.34 a
Fungi	Rhizosphere Soil	12 y	97.43 ± 0.04 a	904.09 ± 23.05 a	4.46 ± 0.05 a
		18 y	97.46 ± 0.41 a	876.56 ± 31.13 a	4.20 ± 0.25 abc
		28 y	97.59 ± 0.67 a	854.45 ± 14.16 ab	4.15 ± 0.09 abc
		38 y	97.65 ± 0.04 a	822.09 ± 22.37 abc	3.88 ± 0.07 c
	Non-rhizosphere Soil	12 y	97.95 ± 0.53 a	764.67 ± 17.44 bcd	4.15 ± 0.12 abc
		18 y	97.54 ± 0.08 a	887.06 ± 3.00 a	4.29 ± 0.17 ab
		28 y	98.11 ± 0.25 a	689.43 ± 80.69 d	3.96 ± 0.12 bc
		38 y	97.98 ± 0.68 a	732.71 ± 26.32 cd	4.07 ± 0.06 bc

“12y”, “18y”, “28y” and “38y” refers to the four consecutive monoculture spans of 12, 18, 28 and 38 years, respectively. Values are presented as means ± standard deviation (n = 3). Means followed by the same letter for a given factor are not significantly different (P < 0.05, Turkey’s HSD test).