Introduction remains which have high level of organic matter,


Organic fertilizer
refers to any decomposed materials of plant and animal origin that supplies
amount of nutrients for plant growth and optimum yield. Organic fertilizer can
be naturallyoccurring which are manure, slurry, peat and guano. Manufactured
organic fertilizer arecomposite, blood meal and bone meal. Nitrogen
is a principal plant nutrient required in greater quantity, its important
component for protein, enzymes and vitamins in plant and it’s essential for
photosynthetic molecule. Nitrogen nutrient can be supplied by, crop residues,
animal and human wastes, and crop rotation with leguminous species (Smil,
2002). Nitrogen bio-fortified organic fertilizer refers to the fertilizer which
are added some nutrients and minerals for crop growth through plant breeding,
transgenic technique or agronomic practices (Bous, et al., 2011). Bio-wastes, is a waste originating from plant and animal
sources which may be degraded or broken down by other living organisms.
Bio-wastes contain yard and park wastes, residue from wood processing
industries, food and kitchen wastes from markets also  vegetables remains which have high level of
organic matter, nutrients and  moisture
and, households, hospitals, restaurants and schools (Hoornweg et al.,

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Onion and spinach are one of the important vegetable
crops grown in Tanzania and used for their nutritional value also serves as a
basic sources of income (Humphry. et al.,
2011). Cramer, (2000) reports that Onion (Allium cepa L.) is an important
vegetable crop in most areas of the world particularly developing countries.






Statement of the
Problem and justification

Continuation of managing
wastes by open dumping and burning of residues lead to losses of nutrients and
organic matter and also cause greenhouse gases emission and other impacts in
the environment like bad odours, leachate production and other side effects on
human health (Varma, et
al., 2014). Instead of dumping in open space, urban wastes can be used
as organic fertilizers by small holder farmers who cannot afford inorganic
fertilizer in vegetable production. This is because urban wastes can be
recycled by decomposing them to be used for agricultural purpose as organic fertilizer
(Farrell et al., 2009). Composting of wastes is more economical when
used as organic fertilizer and benefits the environment by reducing the
emission of green house gases (Lim, et al.,
2015).  Fageria
and Baligar, (2005) and Griffith, (2010) reported that composted wastes contain Nitrogen
(N) for plant growth and development as well as
Potassium (K) and Phosphorus (P) useful in optimum vegetable
production. Most organic fertilizers comprise almost all nutrients required for
onion and spinach growth and development (Funda Y, et al., 2011).

collection and processing of urban wastes, nitrogen bio fortified organic
fertilizer has been produced and used in production of crops in different countries
(Makinde et al., 2001). In Tanzania, there is limited information on the
use of nitrogen bio fortified organic fertilizer made from urban wastes on
onion and spinach production. Therefore, there is a need to explore the benefit
of using nitrogen bio fortified organic fertilizer made from urban wastes on
onion and spinach production to smallholder farmers. Based on the limited information on nitrogen bio
fortified organic fertilizers, this study will focus on nutrient composition,
production effects and optimal application rate on onion and spinach production.



determine the effect of using nitrogen bio fortified organic fertilizer in
onion and spinach production


To characterize
nutrients content in the nitrogen bio fortified organic fertilizer

To assess the response
of spinach and onion treated with nitrogen bio fortified organic fertilizer
under screen house

To determine optimal
amount of nitrogen bio fortified organic fertilizer in production of spinach
and onion under field condition


of Organic fertilizer in Onion and Spinach production

soil biological activity by favouring the root colonisation by mycorrhiza fungi
and rhizosphere bacteria which increase N, P, K and micronutrients in soil by
mobilisation of soluble nutrient, Malusa,
et al, 2007. Improve the soil
physical properties thus enhancing soil structure and water holding capacity
and supplying nutrients for plant growth and prolong the health status by
suppressing some soil borne diseases and parasites Malusaet al 2012. Environment
benefit due to enhancing microbial diversity, reducing soil acidification or
alkalinisation and reduction of greenhouse gases emission Yara, 2010.


Effects of Nitrogen bio
fortified organic fertilizer on onion and Spinach production

application of organic fertilizer  
increased yield and ascorbic acid, soluble sugar   and reduced nitrate contents of onion and
spinach compared to application of inorganic fertilizer, increase growth
vigour  and fruits of crops Daudaet al., 2008. Addition organic
bio fortified fertilizer  has effect on
vegetative growth of crop Aranconet
al., 2005.Organic fertilizer increase soil porosity that lower soil
bulk density and permit root growth, good root system enhance above ground
growth  and development which led to
higher yield production,Baybordi.,et al 2000.

Effects of Organic
fertilizer in soil

fertilizer improve the soil  structure as
well as providing nutrients in soil  which activates species of living organisms
which release phytohormones and stimulate the plant growth and the absorption
of nutrients Arisha et al., 2003 that microorganism require Nitrogen for
multiplication Ouda and Mahadeen, 2008.

Response of onion and
spinach on application of Nitrogen bio fortified fertilizer

et al., (1998) reported that there is increase plant growth on application of
organic fertilizer due to improving soil structure as well as increasing water
retention capacity in soil.