Effects of organic nitrogen fortifiers on some growth parameters of green amaranths (Amaranthus caudatus L.)

Abstract

Chemical fertilizers for boosting crop production are becoming more expensive and scarce. Green amaranth (Amaranthus caudatus L.) is a fast growing and highly nutritious crop, but its common use in the diet of Nigerians is constrained by its high demand for nitrogen fertilizer. Thus, there is a need to find local fertilizer materials that are readily available to peasant farmers. A preliminary field study was conducted to evaluate urine and neem (Azadirachta indica L. juss) as alternative sources for mineral fertilizers in fortifying organic fertilizer (OF) made from cow dung and market waste compost, and OF fortified with urea and bone meal [organo-mineral fertilizer (OMF)], for yield and growth of green amaranth. Fifteen treatments, based on the percentages of N supplied, were NPK15-15-15, OMF, OF, urine, neem and ten treatments of 50, 60, 70, 80 or 90% OF supplemented with a total of 50, 40, 30, 20 and 10% urine or neem, respectively, to provide a total application rate of 100 kg N ha−1, with no fertilizer treatment as a control. Planting was done in two successions (main with fertilizer treatments and residual without further application). The fertilizer sources and levels had significant effects on plant height, number of leaves, stem girth, fresh weight and dry weight. The residual effects were also significant for plant height, number of leaves, total fresh and dry weights. Forty percent N urine amendment of the OF produced the highest total fresh amaranth biomass (269.3 g plot−1 main effect and 110.8 g plot−1 residual effect), which was significantly better than the values of (140 and 35.3 g plot−1, respectively) obtained with respect to OMF during main planting and NPK during residual planting. Results of our study reveal that 40% N urine fortification of OF was a viable substitute for synthetic fertilizers in production of amaranth, and that urine and neem cake can be alternatives to mineral fertilizer for crop production.

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“…The result of the experiment also showed that soil amendments improved soil fertility and increased growth components of white seed melon relative to control. This is consistent with the findings of Liu & Stutzel (2004) and Adeoluwa et al (2010). The result is also in agreement with that of Prasad & Singh (2000) who reported that soils treated with soil amendments increased number of leaves and other growth components compared with untreated soil.…”

“…The use of organic and inorganic fertilizers has been advocated for sustainable soil productivity under intensive and continuous cultivation in southwest Nigeria (Adepetu et al, 1997), sustainable nutrient management on smallholder farms can be achieved by a combination of mineral fertilizers and organic soil amendments (Vanauwe et al, 2004). From this study, the contribution of amendments to soil fertility has clearly shown through increased availability of plant nutrients for its growth and development (Brady & Weil, 2007;Adeoluwa et al, 2010). A combination of organic and inorganic sources of nutrients led to optimal pH of about 6.0-7.0 which is recommended for nutrient availability and suitable for most tropical field and arable crops.…”

Vegetable Amaranths for Summer Greens Production in the Northeastern United States

“…Yield CV and leaf-to-stem ratios of varieties may be useful descriptive measures for new amaranth growers. (AdeOluwa et al, 2009;Edomwonyi and Opeyemi, 2009;Makinde, 2015), the area was fertilized with organic 5N-1.3P-3.3K fertilizer (Pro-Gro 5-3-4; North Country Organics, Bradford, VT). The application rate was 50 lb/acre of N at the time of bed preparation.…”

Nutritional Quality of Tomato (<i>Lycopersicon lycopersicum</i> L.) Varieties as Influenced by Combined Application of Human Urine and Rock Phosphate

“…Human urine as an alternative contains plant nutrients (especially nitrogen) which are cheap, readily available and useful for increase in food production and improving soil fertility [7]. According to [8], the annual amount of human urine of one person corresponds to the amount of fertilizer needed to produce 250 kg of cereal that one person needs to consume per year; thus it is possible to have good quantity of human urine as fertilizer [9] for crop production.…”