Can Leguminous Cover Crops Partially Replace Nitrogen Fertilization in Mississippi Delta Cotton Production?

Table 4

Effect of Austrian winter pea and hairy vetch on soil properties in 2005–2007.^a

Cover crop	04/24/05	05/23/05	04/27/06	05/16/06	04/30/07
	Fluorescein diacetate hydrolytic activity, mmol/kg soil/h
None	121 a	109 a	68 a	80 c	84 c
Austrian winter pea	79 b	108 a	73 a	133 a	130 a
Hairy vetch	91 b	99 a	75 a	100 b	100 b
	pH
None	6.35 a	6.22 a	6.35 a	6.22 a	6.04 a
Austrian winter pea	5.82 c	5.91 b	5.85 c	5.91 b	5.60 b
Hairy vetch	6.10 b	6.04 ab	6.12 b	5.96 b	5.66 b
	Total N content, g/kg soil
None	0.75 b	1.0 b	0.92 b	0.92 b	1.03 c
Austrian winter pea	0.82 a	1.15 a	1.08 a	1.28 a	1.62 a
Hairy vetch	0.73 b	1.07 ab	1.02 ab	1.17 b	1.34 b
	Total organic carbon content, g/kg soil
None	9.0 a	8.8 a	9.2 b	9.9 c	10.5 c
Austrian winter pea	9.3 a	9.3 a	10.8 a	13.1 a	16.1 a
Hairy vetch	8.5 a	9.4 a	10.2 ab	11.6 b	13.5 b

^aMeans followed by the same letter within a column for the same sampling date do not differ at the 95% confidence level.