Adeyele EO, Ayeni LS, Ojeniyi SO (2010). Effect of poultry manure on soil physical - chemical properties, leaf nutrient contents and yield of yam (Dioscorea rotundata) on Alfisol in South Western Nigeria. Journal of American Science 6(10):871-878.

Agbede TM, Adekiya AO, Ogeh JS (2013). Effects of organic fertilizers on yam productivity and some soil properties of a nutrient depleted tropical alfisol. Archives of Agronomy and Soil Science 59(46):803-822
Crossref

Agbede TM, Adekiya AO (2016). Effect of cocoa pod ash and poultry manure on soil properties and cocoyam productivity of nutrient-depleted tropical alfisol. 

View

Agueguia A (2008). Non -destructive estimation of leaf area in cocoyam (Xanthosoma saggittifolium (L) Schott). Journal of Agronomy and Crop Science 171(2):138-141.
Crossref

Ano AO, Agwu JA (2005). Effect of animal manures on selected chemical properties (1): Exchangeable acidity, exchangeable bases and organic carbon. Nigerian Journal of Soil Science 15:14-19.

Asawalam DO, Onyegbule U (2009). Effect of some local liming materials and organic manure on some chemical properties and growth of maize. Nigerian Journal of Soil Science 19(2):71-76.

Ayeni LS, Ayeni OM, Oso OP, Ojeniyi SO (2008). Effect of sawdust and wood ash application in improving soil chemical properties and growth of cocoa (Theobroma cacao) seedlings in nurseries. Agricultural Journal 3(5):323-326.

Ayuba SA, John C, Obasi MO (2005). Effect of organic manure on soil chemical properties and yield of ginger. Nigerian Journal of Soil Science 15:136:138.

Bray RH, Kurtz NT (1945). Determination of total organic and available forms of phosphorus in soil. Soil Science 59:39-45.
Crossref

Bremner JN (1996). Nitrogen - total; In methods of soil analysis part 3 (chemical methods). Soil Science Society of America Inc. Madison Wisconsin USA, pp. 1085-1122.
Crossref

Chigbundu IN, Ofoh M, Obi FC (2010). Productivity of maize/soybean intercropping systems as influenced by different organic manures in Owerri. Proceedings of the 44th Annual conference of Agricultural society of Nigeria. LAUTECH 2010, Ogbomoso Oyo state, pp. 865-867.

Chukwu GO, Nwosu KI (2008). Cocoyam Rebirth: the renaissance of a giant crop. A paper presented at the 17th Annual Conference of Nigeria Rural Sociological Association, NRCRI Umudike, P. 11.

Chukwu GO, Nwosu KI, Mbanasor ENA, Onwubiko O, Okoye BC, Madu TU, Ogbonye S, Nwoko SU (2009b). Development of rapid multiplication technique for cocoyam production. In Proceedings of the 43th Annual conference of Agricultural Society of Nigeria, Abuja, pp. 81-83.

Chukwu GO (2010). Songs for Cocoyam: Nigerian's giant crop. Proceedings of the 44th Annual Conference of Agricultural Society of Nigeria, LAUTECH 2010, Ogbomoso, Oyo state, pp. 875-876.

Eneje RC, Ezeakolam CS (2009). Synergistic effect of poultry manure and sawdust on changes in soil structural indices of a sandy-clay loam Ultisol. Nigerian Journal of Soil Science 19(2):77-87.

Eneje RC, Ukwuoma VE (2005). Plant and animal manure effects on a vegetable and orchard farm soils (part 1): Effects on soil chemical properties. Journal of Agriculture, Agricultural Technology and Environment 1:39-41.

Food and Agriculture Organization (FAO) (1990). Roots, tubers, plantains and banana in nutrition. FAO, Rome, Italy.

Ibeawuchi II (2010). Effect of increasing poultry manure rates on the yield and yield component of Cucubita maxima in Owerri, Ultisol, Imo state. Proceedings of the 44th Annual conference of Agricultural society of Nigeria. LAUTECH 2010, Ogbomoso Oyo state, pp. 231-233.

Iwuagwu MO, Okpara DA, Muoneke CO (2017). Growth and Yield Responses of Cocoyam (Colocasia esculenta (L.) Schott) to Organic Wastes in the Humid Agro-Ecological Zone of South-Eastern Nigeria. International Journal of Plant and Soil Science 16(6):1-11.
Crossref

Kparmwamp A, Kamprath EJ, Gardener R (2004). The effect of sawdust application on soil K and other exchangeable cations. Bioresource Technology 49:173-179.

Magagula NEM, Ossom EM, Rhykerd RL, Rhykerd CL (2010). Effect of chicken manure on soil properties under sweet potato (Ipomoea batata) culture in Swaziland. American Eurasine Journal of Agronomy 3(2):523-544.

Mbah CN, Mbagwu JSC (2006). Effect of animal manures on physico-chemical properties of a Dysteric Leptosol and maize yield in Southeastern Nigeria. Nigerian Journal of Soil Science 16:96-103.

Mbah CN, Nottidge DO, Nwanaga V (2010). Influence of different animal manure on the growth and yield of pepper (Capsicum spp) In: Proceedings of the 44th Annual Conference of Agricultural Society of Nigeria. LAUTECH 2010, Ogbomoso Oyo state, pp. 939-941.

Mukiibi E (2008). Effect of sawdust on soil physical and chemical properties in Ntenjeru Sub Country, Mukono District. Agricultural land use and management of Makerere University, Kampala Uganda. 

View

National Root Crop Research Institute (NRCRI) Umudike (2015) Meterological station. 

View

Nelson DW, Sommers LE (1996). Total carbon, organic carbon, and organic matter, In: methods of soil analysis part 3 (chemical methods). Soil Sci. Society of Am. Inc. Madison Wisconsin USA, pp. 961-1010.
Crossref

Obasi MN, Ano AO, Nwankwo KC (2009). Effect of rate and method of application of rice mill waste (RMW) on growth and yield of two varieties of cocoyam. In Proceeding of the 43th Annual conference of Agricultural Society of Nigeria, Abuja, pp. 16-18.

Oguike PC, Chukwu GO, Njoku CN (2006). Physico-chemical properties of a Haplic Acrisol in Southeastern Nigeria amended with rice mill waste and NPK fertilizer. Nigeria Journal of Soil Science 23:101-111.

Ojeniyi SO, Amusan OA, Adekiya AO (2013). Effect of poultry manure on soil physical properties, nutrient uptake and yield of cocoyam (Xanthosoma sagittifolium) in South west Nigeria. American-Eurasian Journal of Agricultural and Environmental Sciences 13(1):121-125.

Okonkwo BCN, Okore IK, Chukwu GO, Okonkwo JC, Olejede AO (2009). Agronomic potentials of poultry manure and defatted palm kernel cake in sweet potato production on Typic Paleudult. Proceedings of the 43th Annual Conference of the Agricultural society of Nigeria, Abuja, pp. 56-59.

Okoye BC, Onyeukwu CE, Ukoha OO, Asumugha GN, Aniedu OC (2008). Determination of labour productivity on small-holder cocoyam farms in Anambra state, Nigeria. Scientific Research and Essey B, pp. 559-561.
Crossref

Omisore JK, Kasali MY, Chukwu UC (2009). Determination of optimum poultry manure rate for maize production. Proceedings of the 43th Annual Conference of the Agricultural Society of Nigeria, Abuja pp. 260-263.

Onwudike SU, Asawalam DO, Ano AO (2015). Comparative evaluation of burnt and unburnt agro-wastes on soil properties and growth performance of cocoyam in a humid environment. Asian Journal of Agricultural Research 9:276-292.
Crossref

Onwuka IM (2008). Amelioration of soil acidity using local liming materials and their effects on maize performance in an Ultisol of Southeastern Nigeria. A Ph.D thesis. Department of Soil Science and Meterology, Michael Okpara University of Agriculture, Umudike.

Summer ME, Miller WP (1996). Cation exchange capacity and exchange coefficients; In; methods of soil analysis part 3 (chemical methods). Soil sci. Society of America. Inc. Madison Wisconsin USA, pp. 1201-1230.

Thomas GW (1996). Soil pH and Soil Acidity; In: methods of soil analysis part 3 (chemical methods). Soil Science Society of America Inc. Madison Wisconsin USA, pp. 961-1010.

Udo DJ, Ndon BA, Asuquo PE, Ndaeyo NU (2005). Crop production techniques for the tropics. Concept publication Lagos, pp.48-49, 211-216.

Udom BE, Lale, NES (2017). Integrated use of poultry manure and NPK fertilizer on soil properties and cocoyam production. International Journal of Plant and Soil Science 20(5):1-8.
Crossref

Uwah DF, Udoh AU, Okpara SA, Eka MJ, Asawalam DO (2011). Growth and yield of cocoyam (Colocasia esculenta (L.) Schott) following soil amendment with poultry manure and rice husk. Journal of Agriculture, Biotechnology and Ecology 4(2):1-10.