Growth and Nutrient Use Efficiencies of Yams (Dioscorea spp.) Grown in Two Contrasting Soils of West Africa

Table 4

Nitrogen and potassium use efficiency and agronomic use efficiency of Dioscorea spp. as affected by soil type and fertilizers.

Soil type	Species	Fertilizer	Nutrient use efficiency (g of total biomass at harvest/g of total nutrient uptake)		Agronomic efficiency (g of tuber dry weight/g of tuber nutrient content)
			N	K	N	K
Forest	D. alata	None	82	67	87	66
		Full rate	52	61	56	59
	D. rotundata	None	69	76	72	72
		Full rate	51	66	51	65
Savanna	D. alata	None	43	79	46	74
		Full rate	35	71	38	67
	D. rotundata	None	49	106	48	100
		Full rate	36	82	36	81
SE mean (𝑛=32)			9.3	13.5	9.6	12.9