Soil Quality and Water Redistribution Influences on Plant Production over Low Hillslopes on Reclaimed Mined Land

Table 5

Linear and multilinear regressions of perennial forages’ relative yields in 1978-79 versus water redistribution index (WRI), respread soil depth (RSD), and soil quality index (SQI) for soil treatments at Zap and Stanton sites. The third column in each group indicates the sign of regression coefficient(s). For entries with , and other information are not given. At Zap and Stanton sites, and 60, respectively. ns means multilinear regression coefficient has .

-variable(s)			Coefficient sign			Coefficient sign			Coefficient sign
	Zap 1978-79			Zap 1978-79			Zap 1978-79
	Subsoil A			Subsoil B			Subsoil C
WRI		0.103		0.123	0.003	P	0.217	<0.001	P
RSD	0.074	0.021	N	0.197	<0.001	N	0.188	<0.001	N
RSD + WRI	0.074	0.069	N; ns	0.197	<0.001	N; ns	0.225	<0.001	ns; P
SQI	0.075	0.020	N	0.187	<0.001	N	0.221	<0.001	N
SQI + WRI	0.076	0.066	N: ns	0.195	<0.001	N; ns	0.258	<0.001	N; P
	Stanton 1978-79			Stanton 1978-79			Stanton 1978-79
	0 cm topsoil			20 cm topsoil			60 cm topsoil
WRI		0.830			0.109			0.583
RSD		0.418			0.479			0.639
RSD + WRI		0.113		0.250	<0.001	P; P	0.303	<0.001	P; P
SQI		0.386			0.243		0.284	<0.001	P
SQI + WRI		0.103		0.418	<0.001	P; P	0.402	<0.001	P; P

= positive; N = negative.