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Agronomic Performance and Yield of Celeosia argentea and Amaranthus  caudatus Treated With Organic Manure And Mineral Fertilizer

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Amaranthus caudatus 
Celosia argentea 
Chemical fertilizer 
Poultry manure 
Urea fertilizer 
Received: 01.05.2023 
Received in revised form: 
Accepted: 26.05.2023
Most Nigerian soils have low nitrogen status usually supplemented with nutrient sources, like chemical fertilizers. However, the problem with the usage of chemical fertilizer is that though enhances high crop yield, it can result in groundwater pollution, which is hazardous to human health. A field experiment was conducted to evaluate the effect of organic manure, organomineral fertilizer and inorganic (urea)  fertilizer on two vegetable types namely; Celosia argentea and  Amaranthus caudatus. The experiment was carried out at the Teaching and Research Farm, Faculty of Agricultural Science, Ekiti State  University, Ado-Ekiti. The experimental design was a randomized complete block design with three replications. The treatments used in the experiment are; poultry manure applied at the rate of 15 tons/ ha,  organomineral fertilizer (7.5 tons/ha of poultry manure + urea  50kg/ha), Urea (46%N) at 100kgN/ha and control (no fertilizer). The result showed that application of organomineral fertilizer (urea +  poultry manure) to the Amaranthus caudatus gave the highest plant height, stem girth, number of leaves, number of branches of leaves of  45.5 cm, 18.0 cm and 69.7 cm respectively at 4weeks after sowing when compared with values obtained in plots treated with urea,  poultry manure and control. In addition, the application of organometal on the vegetables produced the highest yield and was significantly different from the other sources of nutrients used in the experiment. 


Agricultural land loses fertility after a long period of  cultivation as a result of degradation of soil due to  natural phenomena, and improper land use  management practices over many years. Also, soils  naturally are no longer able to supply all the needed  nutrients required by crops for proper growth and  development. Thus, it becomes imperative to  supplement the soil nutrient with additional nutrient  sources. Fertilizer plays an important role in increasing  the soil nutrients which helps to nourish the plants.  

Thus, fertilizer application is essential for enhancing soil fertility for proper crop production. Common types of fertilizers used in crop production are organic  and fertilizers for good crop productivity. Organic and inorganic fertilizers are essential for plant growth.  Both fertilizers supply plants with the nutrients needed for optimum performance (Erisman et al. 2008).

Organic fertilizers have been used for many centuries whereas chemically synthesized inorganic fertilizers were only widely developed during the industrial revolution. Inorganic fertilizer has significantly supported global population growth, it has been estimated that almost half the people on the  earth are currently fed as a result of chemical fertilizer  use (Erisman et al. 2008).

Commercial and  subsistence farming have been relying on the use of  inorganic fertilizers for crop production (Masarirambi  et al. 2010), because they are easy to use, quickly  absorbed and utilized by crops. But the continued  dependence on inorganic fertilizers has made the  prices of agricultural products skyrocket (Makinde et  al. 2010). Furthermore, the high price of inorganic  fertilizers and the possible environmental hazard  posed by overuse of same, are of great concern. 

Research has shown that organic fertilizers are less  leached into groundwater and cheaper than chemical  fertilizer (Sridhar and Adeoye, 2003). As a result of this  fact, the use of organic fertilizer has found favor in  boosting crop production in Nigeria. In addition, it  improves soil fertility status as well as increases the  income of farmers at a cheap cost of production.  

Celosia argentea L. (Lagos spinach) is an edible species  of the Amaranthaceae family, widely grown in home  gardens in Nigeria and other parts of West Africa. It is  cultivated during the rainy and dry seasons. This green  vegetable is an essential component of people’s diet  in Nigeria. The leaves and young shoots are used in  soups and stews.

The leaves contain high levels of  calcium, phosphorus and iron. The plant is an  important source of vegetable proteins, calories,  vitamins and minerals (Akinyemi and Tijani-Eniola,  1997) that enrich the diet of the people of West Africa.  The crop is produced in Nigeria by poor farmers and in  compound gardens where it is intercropped with  other arable crops like maize and cassava to produce  enough food and meet-up the dietary and cash  requirements of these farmers (Akinyemi and Tijani Eniola, 1997).

Amaranthus caudatus is grown mainly  for its leaves and is among the highest-priced leafy vegetables in Nigeria, one of the important vegetables  of the family Amaranthaceae. Several amaranth  species are useful as food crops and are grown both  for their leaves and for their edible seeds.  Amaranthus, like a number of other vegetables,  requires soil with a high nitrogen content and  adequate nutrient reserve for optimum yield.

Many  researchers have reported that the complementary  use of organic fertilizers is able to give the desired  higher sustainable crop yields than sole use of  inorganic fertilizer (Ogunlade, et al. 2011; Akanbi, et  al. 2010). In addition, most vegetable farmers in  tropical Africa are smallholders who cannot afford the  high cost of inorganic fertilizers. Fertilizer application  rates for intensive agricultural systems have increased  

rapidly in recent years in Nigeria and farmers depend  largely on locally and cheaply sourced organic  fertilizers for enriching their soil (Makinde et al. 2010).  In Nigeria, there are huge amounts of organic manure  sources such as poultry waste, animal dung, sewage  sludge, refuse soil and palm oil mills. The nutrients  contained in manures are slowly released and can be  stored for a longer period in the soil.

This ensures  longer residual effects that help in improving root  development, and higher crop yields (Abou El Magd et  al. 2005). Bayu et al. (2006) reported that the  utilization of organic manure is necessary in order to  reduce the cost of crop fertilization, thus improving  the environmental conditions and reducing the cost of  production.

Organic manure not only helps in sustaining cropping system through improved nutrient recycling (El-Shakweer et al. 1998), it also  provide all necessary macro- and micro-nutrients in available forms on the farm, thereby improving the  physical, chemical and biological properties of the soil  (Abou El-Magd et al. 2006.. Various studies have been  done on how fertilizer use affect the yield of different plants. Several studies have centered on the effect of organic, inorganic fertilizer or in combination on soil  properties, nutrients uptake, growth and yield of  crops.

However, there is scarce research information  on the effect of organic and inorganic fertilizer on  production of Amaranthus caudatus and Celosia  argentea. Thus, to enhance the optimal production of  the vegetables, appropriate use of fertilizers have to  be employed. The aim of this study is to evaluate the  effect of fertilizer types on the growth and yield  performance of Celosia argentea and Amaranthus  cadautus


Experimental site 

This work was carried out March – June, 2022. The site  is located at the Teaching and Research Farm, Ekiti  State University, Ado-Ekiti (Lat. 70 45′ North and Long.  5º 38′ E) and 432 meters above sea level. The texture  of the soil is predominantly loamy sand with some  traces of clay loam. The site is covered with large  vegetation which shows that the site has a good  nutrients to cultivate on it, located on a bearing of 7°  31N and 70 49S and covers an appropriate elevation  of 730m above sea level. The area has a humid tropical  climate with marked wet and dry seasons. It is  characterized by high temperature and relative  humidity.

The average annual rainfall for the area i309mm with an average number temperature is  between 21° and 27°C. The site being part of southern  Nigeria has a rainfall period of about 6 – 7 months and  moderate temperature with relatively assistant  sunshine intensity during the dry season. The  humidity is relatively high during the wet season. The  common weed found on the site is Elephant grass  (Pennisetum purpureum), some wild sunflower  (Tithonia deversifolia), and (Chromolaena odorata)  siam weed. The vegetative cover showed that there  are lots of macros and micronutrient in the soil. 

Land preparation 

After selecting the site, it was cleared and ploughed, it  was harrowed and plots were assigned. The length  and breadth of the site were measured and divided to  three replication, and each replication made up of  eight plots, measuring 2m by 2m, each with 1m in  between, giving total number of twenty-four (24)  plots. Each plot was tilled using a hoe to loosen the  soil, thus providing a good seed bed to enhance the  easy germination of the seeds. 

Experimental Design and Treatment 

The seeds of celosia argentia (Lagos spinach) and  Amaranthus caudatus planted were obtained from  previous planting at the Teaching and Research farm.  The inorganic fertilizer used (urea) was purchased  from the local market, while organic fertilizer was  obtained from the poultry unit of the Teaching and  Research Farm, Ekiti State University, Ado-Ekiti, Ekiti  State.

The experimental design used was a  randomized complete block design (RCBD). The  planting of amaranths and celosia was carried out on  the 25th of March. The poultry manure was applied 2  weeks preceding the planting day, while the  application of urea was done a day before planting.  Planting was done using the broadcasting method.  The treatments used in the experiment are; poultry  manure (PM8) applied at the rate of 15 tons/ ha;  organomineral fertilizer i.e split application of poultry  manure at 7.5 ton/ha and urea (46 % N) at 50 kg/ha  (PM4+U20); Urea (46%N) at 100 kg N/ha (U40) and  control (no fertilizer). 

Data collection  

The data taken include plant height, stem girth,  number of leaves per plant and fresh vegetable  weight/yield. The plant height was measured using meter rule (ruler). Plant height was measured from  base of the plant to its tip, from 14 DAS to 42 DAS. The  number of leaves was measured by counting fully  opened leaves. Stem girth was measured with Vernier  caliper from 14 DAS to 42 DAS on weekly interval.

The  harvesting of vegetables leaves were done 6 weeks  after planting. Yield parameter was measured on the  plants from by selecting the mid rows plants and  uprooted from the root, shaking the soil away gentle,  while the whole plants were placed on a weighing  balance to ascertain weight per plant (fresh vegetable  weight). 

Data analysis 

The data was subjected to Analysis of variance  (ANOVA) using SPSS 23 version (Version 23.0, 2015).  The least significant difference (LSD) test or turkey (α  = 0.05) was used for means separation among the  treatments used. 


Growth parameters measured in the experiment 

Table 1 shows the effects of urea fertilizer, poultry  manure and organomineral on plant height of the two  vegetables varieties used in the experiment. From the  result obtained, it could be clearly seen that there  were no significant differences in all values recorded  for the growth parameters measured on varieties of  vegetables used at different levels of nutrients  applications.

Although application of organomineral  fertilizer (PM4+U20) on Amaranthus caudatus gave  the highest plant height, number of leaves and stem  girth, which are 45.5 cm, 69.7 and 18.0 cm  respectively at four weeks after planting, while the  control (no application) gave the lowest values  recorded in almost all the weeks sampled. 

Yield parameters measured in the experiment  Yield of the different nutrients sources 

Figure1 showed the yield values obtained on the two  vegetable varieties used in this experiment as a result  of the effect of nutrient sources used. From the chart,  it could be seen clearly that application of  organomineral fertilizer (PM4+U20) on the vegetables  varieties gave the highest yield and differ significantly  from all the other treatments used in the experiment,  followed significantly by application of poultry manure (PM8) at the rate of 15 ton/ ha and the control  gave the lowest yield. 

Yield of the two vegetable varieties as affected by the  nutrient sources 

Figure 2 showed the yield values obtained on the two  vegetable varieties used in this experiment as a result  of the influence of nutrient sources used on them.  

From the chart, it could be seen clearly that  application of organomineral fertilizer (PM4+U20) on  the vegetables varieties gave the highest yield,  followed by poultry manure PM8, while the control  gave the lowest yield. In addition, Amaranthus  caudatus produced higher yield under the influence of  treatment PM4+U20 when compare with Celosia  argentea in the experiment. 

Table 1. Plant height (PH), number of leaves (NOL) and stem girth (SG) of the two vegetables under different  nutrient sources. 

WAP (cm)
Veg 4
Nutrient PH NOL SG
CelosiaPM8 4.3 13.2 27.5 7.7 13.3 28.3 0.4 5.5 8.9
PM4+U20 8.3 20.5 42.7 9.3 22.0 51.7 0.6 8.8 16.4
U40 5.2 9.3 16.3 4.7 9.7 20.7 0.2 5.2 8.4
Control 4.7 11.3 22.0 7.3 11.0 22.7 0.3 4.9 8.3
CaudatusPM8 6.8 19.0 38.7 7.0 18.3 40.3 0.5 9.9 16.8
PM4+U20 7.3 17.0 45.5 8.3 36.3 69.7 0.5 10.7 18.0
U40 6.0 11.5 23.0 5.3 8.7 23.7 0.3 6.2 13.8
Control 3.8 7.3 12.2 6.7 6.3 9.7 0.3 4.0 8.2
SEM 1.01 2.75 5.68 0.66 3.01 5.11 0.07 1.57 2.68
p < 0.05 0.300 0.260 0.284 0.604 0.190 0.539 0.355 0.234 0.277

Veg: vegetable; WAP: weeks after planting; PM8: poultry manure; PM+U20: poultry manure + Urea;  U40: 40 g Urea. SEM: standard error of the mean P < 0.05 means a 5% level of probability with means separated by Tukey test. 

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Figure 1. Yield of the different sources of nutrients. PM8: 8 kg poultry manure; PM4+U20: 4 kg poultry manure  + 20 g Urea; U40: 40 g Urea. Bars with different letters differed significantly at 5% level of probability by Tukey  test.

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Figure 2. Yield of the two vegetable varieties as affected by the nutrient sources. PM8: 8 kg poultry manure;  PM4+U20: 4 kg poultry manure + 20 g Urea; U40: 40 g Urea. Bars with different letters differed significantly  at 5% level of probability by Tukey test. 


Fertilizers play an important role in improving soil  fertility by adding essential nutrients to soil which aid  in adequate growth and yield of plants, hence the two  varieties of amaranth grown under different level of  urea fertilizer, and poultry manure (PM) had  significantly showed increased in growth and yield  rate when compared to the control plants.

This effect  could be associated to the vital nutrients contained in  the mineral fertilizer as well as the poultry manure,  which are deposited in the soil and thereby absorbed  by the plants. Also, the two varieties of amaranths  used in this experiment exhibited better response to  organomineral fertilizer and poultry manure than urea  fertilizer and control. This implies that minerals  fertilizer quickly releases nutrients, which can easily  be leached away from the soil than poultry manure.

It  could also be noted that increase in the dosage of the  urea fertilizer and poultry manure had an increment  effect on the plant height, an average number of  leaves, stem girth and yield, which can be attributed  to the increased amount of nutrient (nitrogen)  supplied to the vegetables in the experiment. The  highest plant height obtained from plants treated with  organomineral (Pm4+U20) are 45.5 cm and 42.7 cm,  for caudatus and celosia plants respectively, which  might be due to favorable nutrient mineralization of this fertilizer as a result of the influence of the mineral  component on its organic content (Sikora and Enkiri,  2000), while the control plants produced the shortest  plants height (Fig 1), which could be due to the fact  that they had to rely solely on the native soil fertility  which might be deficient in nutrients.

Figure 2 shows  that organomineral (Pm4+U20) enhanced the  production of leaves and maintained that trend in plant height and stem girth for both caudatus and  celosia. An increase in the number of leaves over the  weeks of samplings are bound to affect the overall  performance of Amaranthus as the leaves serve as a  photosynthetic organ of the plant (Law-Ogbomo and Ajayi, 2009). Although, there were no significant  differences (p< 0.05) in the number of leaves, plant  height and stem girth, obtained from the two  vegetable types used in the experiment, among the  treatments used, and all through the weeks  samplings, all the same, the highest number of leaves,  plant height and stem girth were obtained from plants  (plots) treated with organomineral fertilizer, which  are 69.7, 45.5 cm and 18 cm respectively.

This could  be due to continuous release of nutrients by the  organomineral fertilizer (Ogunlade, et al. 2011). Thus,  the increase in number of leaves under organomineral  and urea fertilizers application, reconfirmed the role  of fertilizer in promoting vegetative growth in leafy  vegetables (Tijani-Eniola, et al. 2000). 

The fresh yield of Amaranthus caudatus was  significantly increased with application of  organomeniral (PM4+U20). These results are in  agreement with the findings of Bruce & Philip (2008)  who reported a linear response of amaranth yield to  N fertilization.

The higher yield produced by the two  vegetables varieties under organomineral treatment  over other treatments used, could have been due to  increased plant height, stem girth and the number of  leaves obtained from the plants under this treatment,  thus the higher performance of vegetables in  PM4+U20 treatment over PM8 and U40 treatments  are indicative of the ease dissolution of nutrients in  the inorganic fertilizer at the initial stage of growth  being a more soluble form, which could be enhanced  by the poultry manure at the later growth stages.

In  addition, poultry manure also contains useful soil  nutrients that are needed for the plant’s growth, but  their composition is in the crude form that is released  slowly to the soil possibly accounting for the slow and  steady growth of plants in both PM4+U20 and PM  treated plots, when compared with urea treated plots  and control. All the fertilizers applied were found to  increase the plant height, stem girth, and yield of  Amaranths caudatus and celosia when compared with  the control. In Fig 2, it could be clearly seen that  Amarantus caudatus produced the highest yield under  the influence of treatment PM4+U20, followed by PM,  then urea while the control plants produced the least.  Furthermore, it can be noted that vegetable yield was  the least in the control plots.

This confirmed the findings of (Olowoake, 2014), who reported the application of organic, mineral and organomineral fertilizers for the enhancement of Amaranthus cruentus yield. There were significant differences (p<  0.05) in the yield of two vegetables under the different treatments used. Fig 1 showed that organometal (PM+U40) treated plots gave the highest yield  compared to other treatments.

This was similar to the  works of Akanni et al. 2011.; Ayeni, 2008.; Ogunlade  et al.; 2011, who reported that the combinations of  organic and mineral fertilizers performed better on  the yield of tomato, maize, and Solanum macrocarpon than when each of them is solely used.  

Application of organic manures significantly increased  levels of organic Carbon and Nitrogen, and the  formation of water stable aggregates, when  compared with application of chemical fertilizers  (N’Dayegamiye, 2006). Makinde et al. (2011), also  reported that Celosia and Corhorus treated with  poultry manure had better yields, higher number of  leaf, stem girth and higher moisture contents than  

vegetables fertilized with urea. The scarcity and high  cost of obtaining mineral fertilizer calls for alternative  nutrient sources (Akanbi et al. 2006), hence this  research work. Also, Celosia as a productive leafy  vegetable, yet its yields are lower when compare with  the yield of Amaranthus caudatus (Denton, 2004). 


This study shows that Amaranthus caudatus and  celosia exhibited a better response to split application  of urea and poultry manure (organomineral) than sole  urea, and poultry manure. Application of treatment  PM4+U20 showed a significant increase in plant  height, stem girth, number of leaves, and fresh weight  (yield) for both celosia and caudatus than all the other  treatments used in the experiment including control,  though caudatus perform better for both growth and  yield parameters.

Therefore, it reveals the need for  basal application of mineral fertilizer for the early  proper growth and development of the vegetable  plants. Organic manure and inorganic manure had a  good influence on growth, development and yield of  these vegetable varieties used. The results obtained  revealed that both vegetables responded well to the  application of organomineral fertilizer compared to  other different nutrients sources used and control in  the study. Therefore poultry manure could be used as  the good organic nutrient source for increasing the  productivity of the vegetables. The study concluded  that leaf numbers increased with increase in poultry  manure and urea fertilizer levels.

This showed that  increase in N level promoted the vegetative growth of  the vegetable plants. This study showed that  treatment PM4+U20 fertilizer gave the best  performances in all growth and yield parameters  measured. Given its superior responses,  organomineral fertilizer could be a very attractive  fertilizer alternative, particularly for annual crops with  short growth cycles such as Amaranthus caudatus and  celosia. It is therefore, reasonable to recommend the  use of organomineral fertilizer in the cultivation of  Amaranthus caudatus and Celosia argentea


Abou El-Magd, M.M.; Mohamed, H.A.; Fawzy, Z.F.  Relationship between growth and yield of  broccoli with increasing N, P or K ratio in a  mixture of NPK fertilizers (Brassica oleracea varital caplenck). Annals of Agricultural  Sciences, 2005, 43: 791-805.

Abou, E.l.; Magd, M.M.; El-Bassiony, M.; Fawzy, Z.F.  “Effect of organic manure with or without  chemical fertilizers on growth, yield and quality  of some varieties of Broccoli plants. Journal of  Applied Sciences Research, 2006, 2(10): 791- 798. 

Adeoye, G.O.; M.K.C.; Sridhar, M.K.C.; Adeoluwa,  O.O.; Oyekunle, M; Makinde, E.A.; Olowoake, A.  A. Comparative evaluation of organo-mineral  fertilizer (OMF) and mineral fertilizer (NPK) on  yield and quality of maize (Zea mays (L)  Moench), Nigerian Journal of Soil Science, 2008,  vol. 18, 141-147. 

Akanbi, W.B.; Baiyewu, R.A.; Tairu, F.M. Effect of  organic based fertilizer and spacing on growth  and yield of Celosia (Celosia. argentea L).  Journal of Agriculture, Forestry and Fisheries, 1, 5-10. 

Akanbi, W.B.; Togun, A.O.; Adediran, J.A. “Ilupeju, E.  A. O. “Growth, dry matter and fruit yields  components of okra under organic and  inorganic sources of nutrients, American Eurasian. Journal of Sustainable Agriculture,  2010, 4 (1), 1–13. 

Akanni, D.I.; Ojeniyi, S.O.; and Awodun., M.A. “Soil  properties, growth yield and nutrient content of  Maize, Pepper and Ama- ranthus as influenced  by organic and organ mineral fertilizer. Journal  of Agricultural Science and Technology, 2011, 1,  1074 – 1078. 

Akinyemi, S.O.S.; Tijani-Eniola, H. “Response of  Celosia argentea L. to different nitrogen sources  and frequency of harvest. (1997) 

Ayeni, L. S, “Integrated application of cocoa pod ash  and NPK fertilizer on soil chemical properties  and yield of Tomato. American-Eurasian Journal  of Sustainable Agriculture, 2008, 2, (3) 333–337. 

Bayu, W.; Rethman N.F.G., Hammers, P.S. and Alemu,  G. (2006). “Effects of farmyard manure and  inorganic fertilizers on sorghum growth, yield  and nitrogen use in a semi- arid area of Ethiopia.  Journal of Plant Nutrition. 29: 391- 407. 

Denton, O.A. “Celosia argentea L. In: Grubben, G.J.H.  & Denton, O.A. (Editors). PROTA 2:  Vegetables/Légumes. [CD-Rom]. PROTA,  Wageningen, Netherlands. 2004 

El-Shakweer, M.H.A.; El-Sayed, E.A.; Ewees, M.S.A. Soil  and plant analysis as a guide for interpretation  of the improvement efficiency of organic  conditioners added to different soil in Egypt.  Communication Soil Science and Plant Analysis,  1998, 29, 2067-2088. 

Erisman, J.; Sutton, M.; Galloway, J. et al. “How a  century of ammonia synthesis changed the  world. Nature Geosci 1, 636–639 (2008). 

Law-Ogbomo, K.E.; Ajayi, S.O. Growth and yield  performance of Amaranthus cruentus  influenced by planting density and poultry  manure application. Notulae Botanicae Horti  Agrobotanici Cluj-Napoca, 2009, 37(2), 195– 199. 

Lucas. “Partitioning of dry matter and nutrients in two  varieties of Amaranths. African Journal of  Agricultural Science, 1998, 12 (1/2), 39-48. 

Mc Leann, E.O. “Soil pH and Lime requirement.  “Agronomy, Advances in Agriculture, 1982, 9,  199–223. 

Masarirambi, M.T.; Hlawe, M.M.; Oseni, O.T.; Sibiya,  T.E. ”Effects of organic fertilizers on growth,  yield, quality and sensory evaluation of red  lettuce (Lactuca sativa L.) ‘Veneza Roxa’.  Agriculture and Biology Journal of North  America, 2010, 1 (6): 1319-1324 

Makinde, E.A.; Salau, A.W.; Odeyemi, O.M.  “Evaluation of poultry manure application rate  and plant population on growth, dry matter  partitioning and nutrient uptake of Cock’s comb  (Celosia argentea L)). International Journal of  Organic Agriculture Research and Development,  2016, 13, 1-17. 

N’Dayegamiye, A.: Mixed paper mill sludge effects on  corn yield, nitrogen efficiency and soil  properties. Agron. J., 2006, 98, 1471-1478. 

Olowoake, A.A.: Influence of organic, mineral and  organomineral fertilizers on growth, yield, and  soil properties in grain amaranth (Amaranthus  cruentus L.), Journal of Organics, 2014, 1 (1)39– 47. 

Ogunlade, M.O.; Adeyemi, E. A.; Ogunleti, D.O.;  Ibiyomi, P.S. “Effect of cocoa pod husk, urea  fortified cocoa pod husk and NPK fertilizers on  the growth and yield of Solanum macrocarpon cultivation, International Journal of Organic  Agriculture Research and Development, 2011, 3,  1–8. 

Sikora, L.J.; Enkiri, N.K. “Efficiency of compost fertilizer blends compared with fertilizer alone.  Journal of Soil Science, 2000, 165(5):444-451 

Sridhar, M.K.C.; Adeoye, G.O.”Organomineral  fertilizer from urban wastes, The Nigerian Field,  vol. 68, pp. 91–111, 2003.Tijani-Eniola, H.; 

Nwagwu, F.A.; Aiyelari O.P. “Response of Celosia argentea L. to different nitrogen sources and frequency of harvest. Proceedings of the 18th Annual Conference of Horticultural Society of Nigeria (HORTSON) (A.D. Akpa, Ed.), 2000, 151-159.