TABLE 4.

Microbial alpha-diversity (Shannon diversity, species richness and Pielou’s evenness) in root-associated soil (RA) and rhizosphere (RH) of lettuce (cv. Tizian).

Diversity Index	Habitat	Organism	HUB-LTE		DOK-LTE
			HU-org	HU-min	BIODYN2	CONMIN
Microbial alpha-diversity (Shannon diversity, species richness and Pielou’s evenness)
Shannon	RA	Bacteria/Archaea	6.68 ± 0.01 Aa	6.73 ± 0.03 Aa	6.42 ± 0.03 Aa	6.33 ± 0.01 Ab
		Fungi	3.33 ± 0.04 Aa	3.39 ± 0.14 Aa	3.39 ± 0.04 Aa	3.37 ± 0.04 Aa
	RH	Bacteria/Archaea	5.29 ± 0.08 Ba	4.49 ± 0.48 Ba	6.29 ± 0.1 Aa	4.67 ± 0.65 Bb
		Fungi	3.36 ± 0.02 Aa	3.07 ± 0.06 Ab	0.68 ± 0.16 Ba	1.12 ± 0.32 Ba
Richness	RA	Bacteria/Archaea	1735.59 ± 12.45 Aa	1723.31 ± 19.86 Aa	1664.18 ± 18.29 Aa	1567.54 ± 8.59 Ab
		Fungi	376.25 ± 2.32 Aa	334.25 ± 7.41 Ab	333.50 ± 9.84 Aa	349.75 ± 5.82 Aa
	RH	Bacteria/Archaea	1007.77 ± 32.82 Ba	829.10 ± 85.15 Ba	1495.93 ± 46.57 Ba	1016.08 ± 140.83 Bb
		Fungi	285.00 ± 8.57 Ba	201.75 ± 8.31 Bb	229.33 ± 20.00 Ba	193.00 ± 14.53 Ba
Pielou	RA	Bacteria/Archaea	0.90 ± 0 Aa	0.90 ± 0 Aa	0.87 ± 0 Aa	0.86 ± 0 Aa
		Fungi	0.56 ± 0.01 Ba	0.58 ± 0.02 Aa	0.58 ± 0 Aa	0.58 ± 0.01 Aa
	RH	Bacteria/Archaea	0.77 ± 0.01 Ba	0.67 ± 0.06 Ba	0.86 ± 0.01 Aa	0.67 ± 0.08 Aa
		Fungi	0.59 ± 0 Aa	0.58 ± 0.01 Aa	0.12 ± 0.03 Ba	0.21 ± 0.06 Ba

The plants were grown in minirhizotrons for nine weeks in soils with long-term organic (HU-org, BIODYN2) or mineral (HU-min, CONMIN) fertilization history. Data represent means ± standard errors of four independent replicates. Different lowercase letters indicate significant differences between organic vs. mineral fertilization tested separately per site, habitat and organism by t-test (p ≤ 0.05). Different capital letters indicate significant differences between root-associated soil vs. rhizosphere tested separately per site, fertilization and organism by t-test (p ≤ 0.05).