Enhanced soil aggregate stability limits colloidal phosphorus loss potentials in agricultural systems

Environmental Sciences Europe

Table 4 Results from correlation analyses and stepwise linear regressions of colloidal P and colloidal P/TDP in different-sized aggregates with soil aggregate-associated mean weight diameter (MWD), geometric mean diameter (GMD), pH, total carbon (TC), total nitrogen (TN), C/P, C/N, Al, Fe, and Ca

Indexes	Aggregate sizes	TC	TN	TP	pH	Al	Fe	Ca	C/P	C/N	MWD	GMD
Colloidal P	Total	0.151	0.134	0.706**	0.223*	0.220*	0.251**	0.269**	− 0.424**	0.241*	0.224*	− 0.101
	2–8 mm	0.302	0.328	0.769**	0.095	0.374*	0.464*	0.492**	− 0.517**	0.118	0.136	− 0.247
	0.26–2 mm	0.089	0.129	0.796**	0.012	0.277	0.317	0.142	− 0.644**	0.102	0.102	− 0.264
	0.053–0.26 mm	0.149	0.128	0.662**	0.311	0.204	0.190	0.085	− 0.461*	0.295	0.290	− 0.124
	< 0.053 mm	0.282	0.101	0.344	0.631**	− 0.115	− 0.085	0.588**	0.127	0.541**	0.528**	0.189
Colloidal P/TDP	Total	− 0.522**	− 0.471**	0.026	− 0.301*	0.474**	0.365**	− 0.373**	− 0.449**	− 0.298*	− 0.072	− 0.056
	2–8 mm	− 0.509	− 0.452	0.315	− 0.387	0.764**	0.707**	− 0.441	− 0.807**	− 0.435	− 0.048	− 0.030
	0.26–2 mm	− 0.645**	− 0.547*	0.147	− 0.436	0.741**	0.513	− 0.688**	− 0.632*	− 0.411	− 0.090	− 0.097
	0.053–0.26 mm	− 0.485	− 0.429	− 0.008	− 0.435	0.515*	0.458	− 0.711**	− 0.364	− 0.234	− 0.082	− 0.025
	< 0.053 mm	− 0.386	− 0.455	− 0.322	0.107	0.247	0.104	0.261	− 0.013	0.002	− 0.074	− 0.086

Stepwise linear regression	Colloidal P			Stepwise linear regression	Colloidal P/TDP
Stepwise linear regression	R²	F	P	Stepwise linear regression	R²	F	P
	0.605	44.116	< 0.001		0.539	16.058	< 0.001
	B	t	P		B	t	P
(Constant)	− 8.017	− 2.979	0.004	(Constant)	0.478	2.98	0.004
Al	0.087	3.235	0.018	TC	− 0.028	− 6.947	< 0.001
TP	10.598	3.88	< 0.001	Fe	0.015	4.883	< 0.001
TN	− 2.257	3.634	0.004	MWD	0.413	3.911	< 0.001
MWD	5.977	− 2.651	< 0.001	GMD	− 0.363	− 2.057	0.044