Effects of Organic and Inorganic Fertilizers, Cost Benefit- analysis on the Growth, Biomass Yield and Proximate Analysis of Amaranth (Amaranthus quitensis L.)

Africa is currently faced with food and nutritional insecurity and strategies to mitigate this problem include the increased production of vegetables through the utilization of organic manure and inorganic fertilizers, considering the input to output, in relation to availability and affordability. The objectives of this research were to determine the response of amaranth to organic, inorganic and biofertilizer sources and to determine the effect of fertilizer cost on production.

The experiments were conducted with three rates of NPK, Pig manure, supergro and control in a randomized complete block design. Data obtained were analyzed using Statistical analytical system. Cost benefit-analysis was also used to identify the best of fit in relation to cost among the fertilizers.

Plant height varies significantly among the treatments at various weeks. 10 tonnes pig manure (OM10T) was significant for plant height (16.74 cm) at 2 weeks. Pig manure at 10 tonnes (OM10T) had significant differences for number of leaves at weeks of observation, while pig manure at 15 tonnes (OM15T) showed the highest chlorophyll content at 3 weeks. Proximate analysis revealed that levels of fertilizer treatments significantly influenced the nutritional composition of A. quitensis leaves. Pig manure at 5T/ha had the highest fat, protein, zinc, copper and iron contents. Analysis of variance (ANOVA) showed significant effects of fertilizer treatments on observed traits and proximate composition. Cost benefit ratio was best for pig manure and had the best returns for potential investors in amaranth production.