Table 6.

Linear regression between soil analyses and numbers of Rhizobium leguminosarum bacteria estimated by different MPN and qPCR approaches^a

Predictor used	Variate	% variance accounted for by regression		P value		Slope
		Woburn	Watlington	Woburn	Watlington	Woburn	Watlington
Rhizobium leguminosarum bv. trifolii MPN	Total Zn	59	77	<0.001	<0.001	−0.01	−0.01
	Soil solution Zn	20	67	NS	<0.001	−1.46	−8.49
	NH4NO3-extractable Zn	34	74	<0.05	<0.001	−5.11	−15.47
Rhizobium leguminosarum bv. viciae MPN	Total Zn	79	*	<0.001	*	−0.02	*
	Soil solution Zn	40	*	<0.01	*	−3.06	*
	NH4NO3-extractable Zn	52	*	<0.01	*	−9.29	*
Rhizobium leguminosarum 16S rRNA	Total Zn	38	50	<0.01	<0.01	−0.0034	−0.003
	Soil solution Zn	13	47	NS	<0.01	−0.47	−2.50
	NH4NO3-extractable Zn	18	26	NS	<0.05	−1.531	−3.39
Rhizobium leguminosarum bv. trifolii nodD	Total Zn	56	85	<0.001	<0.001	−0.01276	−0.02
	Soil solution Zn	8	86	NS	<0.001	−1.327	−18.46
	NH4NO3-extractable Zn	7	77	NS	<0.001	−3.71	−25.06
Rhizobium leguminosarum bv. viciae nodD	Total Zn	59	53	<0.001	<0.001	−0.00582	−0.01
	Soil solution Zn	26	33	<0.05	<0.05	−0.770	−6.90
	NH4NO3-extractable Zn	22	27	<0.05	<0.05	−2.31	−11.00

^a*, not measured; NS, not significant.