Chemical Properties of Soil, Yield and N, P, K Uptake by Okra as affected by Commercially produced Organic Based Fertilizers By OLOWOKERE, F. A., AJUFO, C. A. AND OJOWA, F. D. INTRODUCTION Sources of commercial production of organic based fertilizers were reported to be few in Nigeria some years ago (Adeoye, 2005). With improved awareness in organic agriculture by the efforts of the following organic bodies: * Organic agriculture Network (NOAN), * Government Agencies like Ladoke Akintola University (Mustapha et. al., 2011) * Organic Agriculture Project in Tertiary Institutions in Nigeria (OAPTIN), * West African Network of Organic Agriculture Research and Training (WANOART), organic agriculture is gradually gaining acceptance and it is being practiced on a large scale level. This then necessitates the production of organic based fertilizers. Many organic fertilizer producing companies are therefore springing up. Commercial production of organic based fertilizers becomes relevant for the following reasons: * The time required for the preparation of the fertilizers could be used for other activities on the farm. * Some of the organic based fertilizers are produced to be crop specific. * Materials with additional properties could be included in the fertilizers. It is therefore necessary to compare the fertilizers produced by different companies to ascertain their efficiencies. MATERIALS AND METHODS The experiment was carried out at the screen house of the College of Plant Science and Crop Production, Federal University of Agriculture, Abeokuta (Long. 3° 37´ N and Lat. 7° 68´ E). Names of Organic based fertilizers used for the experiment: 1. Neem organo compound fertilizer produced by National Research Institute for Chemical Technology, Zaria. 2. Sunshine organo-mineral fetilizer produced by the Ondo State Government. 3. Providence organic fertilizer produced by Olaku Industries Nigeria limited, Abeokuta, Ogun State 4. Gateway Organic fertilizers produced by the Ogun State Government MATERIALS AND METHODS CONT’D Rate of fertilizers Used: 10 t/ha Weight of soil used: 12 kg/pot Number of replications: 4 Experimental Design: CRD Test Crop : Okra (Abelmoschus esculentus) Variety: NHAE 47-4 MATERIALS AND METHODS CONT’D DATA COLLECTION: The following parameters were observed weekly between 3 and 6 weeks after planting: Plant Height: This was done with the aid of a meter rule Number of Leaves: By physical counting Yield was measured by harvesting okra fruits at three days interval, these were weighed with a balance. MATERIALS AND METHODS CONT’D PLANT SAMPLING: Okra plant samples were cut at soil level at full bloom, oven dried at 65°C to constant weighed and milled for analysis. SOIL SAMPLING: Pre- planting soil sampling was done before fertilizer application while soil samples were collected from each experimental plot at the end of the experiment, these were air dried, ground and sieved with 2 and 0.5 mm sieves. MATERIALS AND METHODS CONT’D PLANT ANALYSIS: Nitrogen, phosphorus and potassium in the plant samples were determined by Kjeldahl, vanadomolybdate (Juo, 1982) and flame photometry respectively. Uptake was determined by multiplying the concentrations of the above nutrients with the dry weights of okra plants. MATERIALS AND METHODS CONT’D FERTILIZER ANALYSIS: The fertilizers used for the experiment were analyzed for N, P and K using the above methods, pH was determined by Glass electrode method while organic carbon was by Walkley Black method. SOIL ANALYSIS: Particle size analysis was done by hydrometer method (Udo and Ogunwale, 1986), nitrogen by Kjeldahl method (Bremner, 1996), organic carbon by Walkley Black method (Nelson and Sommers, 1989), Phosphorus by Bray 1 method (Bray and Kurtz, 1945). Calcium and Magnessium were determined by flame photometry. MATERIALS AND METHODS CONT’D STATISTICAL ANALYSIS: Data obtained was subjected to the Analysis of Variance, means were separated by Duncan’s Multiple Range Test at 5 % probability level. RESULTS Table 1: Particle size distribution and chemical characteristics of pre- planting soil Property Value pH 7.02 O. M. (%) 0.79 Nitrogen 9%) 0.13 Phosphorus (mg/kg) 7.13 Potassium (cmol/kg) 0.18 Ca (cmol/kg) 0.16 Mg (cmol/kg) 1.27 Particle size Sand (%) 77 Clay (%) 14 Silt (%) 9 Texture Loamy sand Table 2: Chemical properties of different commercially produced organic based fertilizers Fertilizer NM pH (H2O) 7.07 N (%) P (%) K (%) 3.24 3.28 2.73 37.69 GT 7.50 2.10 3.41 2.15 53.95 SH 9.03 2.13 0.86 0.84 76.74 PR 8.41 6.72 1.04 1.41 49.45 SH – Sunshine organo-mineral fertilizer PR – Providence organic fertilizer NM – Neem organo compound fertilizer GT – Gateway organic fertilizer O. C. (%) Table 3: Effect of Different Commercially Produced Organic Based Fertilizers on okra plant height (cm) Treatment 3 WAP 4 WAP 5 WAP 6 WAP Control SH PR NM 12.43 15.45 14.73 14.08 16.57 20.57 18.43 19.62 24.42 28.67 27.50 25.75 33.67 39.00 35.40 39.30 GT 15.82 NS 21.38 NS 29.38 NS 40.42 NS SH – Sunshine organo-mineral fertilizer PR – Providence organic fertilizer NM – Neem organo compound fertilizer GT – Gateway organic fertilizer NS – Not Significant WAP – Weeks after planting Table 4: Effect of different commercially produced organic based fertilizers on the number of leaves of okra Treatment 3 WAP 4 WAP 5 WAP NM SH PR GT 5.17 5.00 4.67 4.17 5.83ab 6.17a 5.83ab 5.50ab 6.67 7.17 7.33 6.17 7.33 7.83 7.67 8.00 Control 4.17 NS 4.17b 6.50 NS 7.00 NS SH – Sunshine organo-mineral fertilizer PR – Providence organic fertilizer NM – Neem organo compound fertilizer GT – Gateway organic fertilizer NS – Not Significant WAP- Weeks after planting 6 WAP Table 5: N, P and K uptake by okra grown with commercially produced organic based fertilizers Treatment N (mg/g) P (mg/g) K mg/g) GT SH NM PR 15.00 28.29 33.50 14.25 2.21 2.50 1.82 0.95 26.46ab 27.21ab 40.10a 26.21ab Control 14.36 NS 1.75 NS 12.33b SH – Sunshine organo-mineral fertilizer PR – Providence organic fertilizer NM – Neem organo compound fertilizer GT – Gateway organic fertilizer NS – Not Significant 50 a 45 Fruit Yield (g/plot) 40 35 ab ab 30 ab 25 20 b 15 10 5 0 Control NM Treatment SH PR GT Figure 1: Effect of different commercially produced organic based fertilizers on okra yield. Table 6: Nitrogen, phosphorus and potassium contents of post planting soil as affected by different types of organic based fertilizers. Treatment N (%) P (mg/kg) GT 0.16a 23.86c 0.16d SH 0.13ab 47.41a 0.36b NM 0.13ab 18.67d 0.43a PR 0.13ab 41.30b 0.27c Control 0.12b 14.40e 0.15d SH – Sunshine organo-mineral fertilizer PR – Providence organic fertilizer NM – Neem organo compound fertilizer GT – Gateway organic fertilizer K (cmol/kg) RECOMMENDATION Okra could be planted with gateway organic, sunshine organo-mineral, neem organo compound and providence organic fertilizers for improved yield, crop and soil qualities. However, it is recommended that this experiment has to be conducted on the field before making any conclusion. REFERENCES Adeoye, G. O. (2005). Organic Agriculture: A review and possible adoption for food security in Nigeria. Proceedings, 1st National Conference on Organic Agriculture, UNAAB, Abeokuta, Nigeria, 25-28th October, 2005, pp. 3-14. Bremner, J. M. (1996). Total Nitrogen. In: C. A. Black (ed.). Methods of Plant Analysis 3rd edition Part 3, Agronomy 9. American Society of Agronomy. Madison Wisconsin, pp 901. Juo, A. S. R. (1982). Automated and Semi automated methods for soil and plant analysis manual series, No. 7, published and printed by International Institute of tropical Agriculture (IITA), Ibadan, Nigeria. 33pp. REFERENCES CONT’D Mustapha, S. B., Bzugu, P. M. and Sanusi, A. M. (2012). The need for organic farming extension in Nigeria. Journal of Environmental Management and Safety. Vol. 3 (1). 44-53. Nelson, K. E. and Sommers, L. F. (1982). Total carbon, organic carbon and organic matter. In: Page, A. L. et al., (Ed.) Methods of Soil Analysis. Part 2. Agronomy, No. 9, Madison Wisconsin, U. S. A.