Changes in Soluble-N in Forest and Pasture Soils after Repeated Applications of Tannins and Related Phenolic Compounds

Table 3

Soluble-N (mg kg⁻¹ soil) extracted with treatment solutions^†.

	Single treatment			Cumulative after treatment 8			Cool water			Hot water			Final total
Trt	Forest	Pasture		Forest	Pasture		Forest	Pasture		Forest	Pasture		Forest	Pasture
			Avg.; (𝑛=8)			Avg.; (𝑛=8)			Avg.; (𝑛=8)			Avg.; (𝑛=8)			Avg.; (𝑛=8)
H2O	70 (1)	94 (10)	82 (7)AB	147 (4)	186 (19)	166 (11)AB	4.9 (0.3)	5.8 (0.8)	5.3 (0.4)AB	107 (4)	191 (27)	149 (20)A	259 (6)	383 (45)	321 (31)A
MG	83 (3)	102 (10)	93 (6)A	166 (6)	193 (19)	179 (11)A	5.5 (0.5)	5.7 (0.5)	5.6 (0.3)A	98 (5)	170 (26)	134 (18)AB	269 (10)	368 (44)	319 (28)A
CAT	70 (1)	91 (8)	81 (6)AB	137 (3)	165 (14)	151 (9)BC	4.2 (0.4)	4.8 (1.0)	4.5 (0.5)BC	91 (3)	166 (24)	129 (18)AB	231 (6)	336 (37)	284 (26)A
SOR	65 (1)	82 (8)	74 (5)BC	136 (3)	154 (13)	145 (7)BC	6.2 (0.3)	5.4 (0.5)	5.8 (0.3)A	95 94)	129 (8)	112 (8)BC	237 (6)	289 (20)	263 (14)A
GA	69 (1)	75 (7)	72 (3)BC	131 (3)	131 (12)	131 (6)CD	5.5 (0.4)	5.0 (0.4)	5.3 (0.3)AB	107 (3)	148 (19)	128 (12)AB	244 (5)	284 (31)	264 (16)A
TA	61 (1)	70 (5)	66 (3)C	110 (2)	116 (9)	113 (5)DE	5.0 (0.7)	4.5 (0.7)	4.8 (0.5)ABC	86 (3)	106 (9)	96 (6)CD	201 (4)	226 (17)	213 (10)B
PGG	53 (2)	61 (6)	57 (3)D	105 (3)	110 (9)	108 (4)E	4.2 (0.2)	4.0 (0.5)	4.1 (0.2)C	78 (4)	99 (8)	89 (6)D	188 (4)	213 (17)	200 (9)B
Avg. (𝑛=28)	67 (2)Y	82 (4)X		133 (4)Y	151 (8)X		5.1 (0.2)	5.0 (0.2)		95 (2)Y	144 (9)X		233 (6)Y	300 (16)X

^†Treatment solutions consisted of a water control or supplied 10 mg of methyl gallate (MG), gallic acid (GA), catechin (CAT) condensed tannin from sorghum (SOR), tannic acid (TA), or β-1,2,3,4,6-penta-O-galloyl-D-glucose (PGG) per g soil. Data are arithmetic average (standard error) (𝑛=4). Main effects of land use (column averages, 𝑛=28) or treatments (row averages, 𝑛=8) are denoted by capital letters (Tukey’s HSD, 𝑃<0.05).