Dry Matter Production, Nutrient Cycled and Removed, and Soil Fertility Changes in Yam-Based Cropping Systems with Herbaceous Legumes in the Guinea-Sudan Zone of Benin

Table 9

Total plant nitrogen, phosphorus, and potassium (kg ha⁻¹) dry matter removed in the crop harvest and those returned to the soil in yam-based cropping systems (2002-2003 and 2004-2005 cropping seasons, four cropping system treatments, four village sites, 32 farmers, Benin).

		2002-2003 cropping seasons						2004-2005 cropping seasons
		T0	TM	TMA	TMM	LSD	SD	T0	TM	TMA	TMM	LSD	SD
Total nutrients removal through harvest (kg ha^−1)	N	19.35	49.44	61.80	61.22	2.91	4.46	16.49	43.01	58.09	57.18	2.90	4.44
	P	1.99	6.80	8.05	7.93	0.39	0.60	1.69	5.97	7.33	7.19	0.38	0.57
	K	21.39	20.44	34.53	34.93	2.16	3.30	18.23	16.61	37.05	37.00	2.31	3.54
Total nutrients recycled through plant biomass (kg ha^−1)	N	61.64	42.41	167.17	189.54	10.68	16.33	58.75	41.61	158.66	183.17	11.59	17.72
	P	7.17	6.00	15.36	18.52	2.21	3.37	6.40	5.56	15.25	17.47	2.09	3.20
	K	37.47	30.71	79.66	81.77	3.24	4.95	34.14	27.62	76.84	81.54	3.94	6.03

Means with the same letter within row are not significantly different ().
T0 (control 1): one-year fallow-yam rotation; TM (control 2): maize-yam rotation; TMA: A. histrix/maize intercropping-yam rotation; TMM: M. pruriens/maize intercropping-yam rotation; SD: standard deviation; LSD: least square difference at 5%.