Asian Journal of Agriculture and Rural Development, 3(5) 2013: 234-248 234 Response of Grain Weight of Maize to Variety, Organic Manure and Inorganic Fertilizer in Asaba Area of Delta State Enujeke E. C. 1 Department of Agronomy, Delta State University, Asaba Campus, Nigeria Abstract This study was carried out in the Teaching and Research Farm of Delta State University, Asaba Campus from March 2008 to June 2010 to evaluate the response of grain weight of maize to variety, organic manure and inorganic fertilizer. The experiment was carried out in a Randomized Complete Block Design (RCBD) replicated three times in a factional layout. Four different rates of poultry manure, cattle dung and NPK 20:10:10 fertilizer were applied to three maize varieties sown at 75cm x 15cm and evaluated for the grain weight. The results obtained indicated that hybrid variety which produced yield of 2.1 tha -1 in 2008 and 2.3 tha -1 in 2009 was superior. The results of interaction showed that variety, manure type and rates of application were significantly (p<0.05) different in 2008 and 2009. Based on the findings of the study, it is recommended that (i) Hybrid maize variety, 9022-13, which was outstanding in grain weight be grown in the study area. Alternatively, farmers who prefer open-pollinated varieties could grow BR9922-DMRSF2 or Agbor local variety for farmers who prefer local varieties in maize production. (ii) Farmers who prefer mineral fertilizers for increased grain weight of maize should apply 450kgha -1 of NPK 20:10:10. (iii) Farmers who practice organic agriculture in Asaba agro-ecological zone should apply 30tha -1 of poultry manure to enhance maize yield. Keywords: Grain weight of maize, variety, organic manure and fertilizer, Asaba area of Delta State Corresponding author email: enujeke@yahoo.com Asian Journal of Agriculture and Rural Development journal homepage: http://aessweb.com/journal-detail.php?id=5005 mailto:enujeke@yahoo.com Asian Journal of Agriculture and Rural Development, 3(5) 2013: 234-248 235 Introduction Maize (Zea mays L) is one of the major cereal crops grown in the humid tropics and Sub-Saharan Africa. It is a versatile crop and ranks third following wheat and rice in world production as reported by Food and Agriculture Organization (FAO, 2003). Maize crop is a key source of food and livelihood for millions of people in many countries of the world. It is produced extensively in Nigeria, where it is consumed roasted, baked, fried, pounded or fermented (Agbato, 2003). In advanced countries, it is an important source of many industrial products such as corn sugar, corn oil, corn flour, starch, syrup, brewer’s grit and alcohol (Dutt, 2005). Corn oil is used for salad, soap- making and lubrication. Maize is a major component of livestock feed and it is palatable to poultry, cattle and pigs as it supplies them energy (Iken et al., 2001). The stalk, leaves, grain and immature ears are cherished by different species of livestock (Dutt, 2005). In spite of the increasing relevance and high demand for maize in Nigeria, yield across the country continues to decrease with an average of about 1 t/ha which is the lowest African yield recorded (Fayenisin, 1993). The steady decline in maize yield can be attributed to: 1. Rapid reduction in soil fertility caused by intensive use of land and reduction of fallow period as reported by Directorate of Information and Publications of Agriculture.(DIPA, 2006). 2. Failure to identify and plant high yielding varieties most suited or adapted to each agro-ecological zone (Kim, 1997; Olakojo, et al.1998). 3. Use of inappropriate plant spacing which determines plant population and final yield (Zeidan et al., 2006). 4. Negligence for soil amendment materials such as organic manure and inorganic fertilizers which improve soil condition and enhance crop yield. Tolera et al. (1999) suggested that breeders should select maize varieties that combine high grain yield and desirable stover characteristics because of large differences that exist between cultivars. Odeleye and Odeleye (2001) reported that maize varieties differ in their growth characters, yield and its components, and therefore suggested that breeders must select most promising combiners in their breeding programmes. Sonetra et al. (2002) suggested that subsistence farmers should apply organic manure directly to the soil as a natural means of recycling nutrients in order to improve soil fertility and yield of crops. Manures and fertilizers are the life wire of improved technology contributing about 50 to 60% increase in productivity of food grains in many parts of the world, irrespective of soil and agro-ecological zone (DIPA, 2006). Reijnties et al. (1992) and Adepetu et al. (2005) remarked that the downward trend in food production should prompt farmers to Asian Journal of Agriculture and Rural Development, 3(5) 2013: 234-248 236 amend the soil with different materials in order to enhance growth and yield of crops. Several organic materials such as cattle dung, poultry dropping, pig dung and refuse compost have been recommended to subsistence farmers in West Africa as soil amendments for increasing crop yield (Sobulo and Babalola, 1992; Ismail et al., 1999; Olayinka, 1996 and Olayinka et al., 1998). Enujeke (2013) recommended the application of 450kgha-1 of NPK 20: 10:10 or 30 tha-1 of poultry manure for increased grain yield of maize. The report further argued that poultry dropping and cattle dung increases root growth of maize and the crop extracts soil water more efficiently for increased grain yield. Municipal wastes were reported to have reduced soil temperature, increased soil water, nutrient status and the yield of maize in temperate soils (Movahedi et al., 2000). Cattle dung has been reported to contain 0.3 – 0.4 % N, 0.1 – 0.2 % P and 0.1 – 0.3 % K (Subedi and Gurung, 1991). According to Adekunle et al., (2005) cattle dung applied at the rate of 10 t/ha to cowpea resulted to increased plant height, leaf area, pod number, pod weight as well as improved soil structure in a mixed farming system. Stefan (2003) indicated that fresh poultry dropping contain 70% water, 1.4% N, 1.1% P2O5 and 0.5% K2O while dried poultry manure contains 13% water, 3.6% N, 3.5% P2O5 and 1.6% K2O. Ayodele (1993) reported that inorganic fertilizer are known to influence the quantity and yield of maize. Iken and Anusa (2004) recommended an optimum plant population of 53,333 plants/ha for maximum yield of maize. Their report indicated that this is obtainable using a spacing of 75cm x 25cm at 1 plant per stand or 75cm x 50cm at 2 plants per stand. Azam et al., (2007) reported that spacing of 75cm x 35cm resulted in increased grain yield of maize while 75cm x 15cm gave maximum cob weight. Similar report by Allessi and Power (2004) revealed that maize cob weight decreased with increased plant population. At present, some farmers in Asaba area not only neglect the use of fertilizers or soil amendments but also sow any maize variety of their choice and these do not translate into expected high grain yield in the study area. Hence, there are no recommended standards taking into consideration the different combinations of such cultural practices as varietal selection, rates of appropriate organic manure and mineral fertilizer which interplay to influence yield and optimal performance of maize in Asaba area of Delta State. Against this background, the broad objective of this study, therefore, was to: identify variety of maize most suited or adapted to Asaba area, fertilizer types and rates for the variety. The specific objectives were to: (i) identify the best variety of maize for Asaba area (ii) determine the effects of NPK (20:10:10) mineral fertilizer, poultry manure, cow dung on maize grain weight. Materials and Methods Site Description Asian Journal of Agriculture and Rural Development, 3(5) 2013: 234-248 237 The study was carried out in the Teaching and Research Farm of Delta State University, Asaba Campus from March to December 2008 and repeated between March and December, 2009. Asaba is located at latitude 06 o 14’N and longitude 06 o 49’N of the equator. It lies in the tropical rainforest zone dominated by mangrove, fresh water, swamps, humid forests and secondary vegetation (NEST, 1991). Its climate is influenced by the movement of the Inter- Tropical Discontinuity (ITD). The IDT is made up of two wind systems namely the moisture-laden South-West monsoon from the Atlantic Ocean and the dry cold North- East trade wind from the Sahara desert. The South-West Trade wind most significantly determine the climate condition of Asaba area of Delta State. Asaba is characterized by raining season between April and October, with annual mean-rainfall of 1500mm and 2000mm maximum. The distribution is bimodal with peak in July and September, coupled with a period of low precipitation in August. Mean temperature is 23.8 o C with 37.3 o C as maximum. Relative humidity is 77.2%, the mean monthly soil temperature at 100m depth is 20.3 o C, while sunshine stands at 4.8 bars (Meteorological Office, Asaba, 2003). Pre-planting Soil Analysis Representative surface soils (0-20cm) were sampled with a tubular sampling auger. These soil samples were air-dried at room temperature for 5 days and crushed to pass through a 2mm mesh sieve. Sub-samples from the bulked soil sample were further grounded to pieces to pass through 100mm- mesh sieve for the determination of organic matter. The rest samples were then analyzed to determine the physical and chemical properties of the soil. The analysis was done at Delta State University, Asaba campus. Analytical Procedure Physical Properties Particle Size Distribution: Particle size distribution was analyzed using the Bouyoucos hydrometer method in which 0.5 N Sodium hexameta-phosphate was used as dispersant (Landor, 1991). Bulk density: The bulk density (Bd) was determined by Core-method. Particle density: This was determined by pycometer or specific gravity bottle method as described by Bowles (1992). Chemical Properties Soil pH: This was determined in soil: water suspension (1:1) using glass electrode pH- meter as described by Mclean (1982). Organic Carbon: This was determined using the wet oxidation method of Walkley and Black (Walkley and Black, 1945). Total Nitrogen: This was determined using the modified KJeldah distillation method as described by Landor (1991). Exchangeable Cations (EC) and Effective Cation Exchange Capacity (ECEC): Exchangeable cations were determined by extracting the cations with IN ammonium acetate (IN, NHOAC) as displacing solution, buffered at pH7 as described by Brady and Weils (1999). The extract was then determined electrochemically using atomic absorption spectrophometry. The effective Asian Journal of Agriculture and Rural Development, 3(5) 2013: 234-248 238 cation exchange capacity (ECEC) was calculated as the sum of exchangeable bases (Ca, Mg, K and Na) and exchangeable A1 and H expressed in cmo1/kg -1 of soil. Exchangeable Acidity: This was determined by titration method as described by Juo (1981). The exchangeable H + and A1 ++ were then expressed in cmo/kg -1 of soil Available Phosphorus: This was determined by Bray No.1 method as described by Landor (1991). Cation Exchangeable Capacity: This was determined by neutral NH4- Acetate placement method using the procedure of Anderson and Ingram (1996). Aim of the Experiment The experiment was aimed at testing the response of three selected maize varieties to different rates of organic manure and inorganic fertilizer (NPK 20:10:10) Experimental Design The study was carried out in Randomized Complete Block Design (RCBD), replicated three times in a factorial layout. The factors were three sources of nutrients:- poultry manure (PM), cattle dung (CD), inorganic fertilizer (NPK 20:10:10). The different rates of PM were 0, 10, 20, 30t/ha, CD were 0, 10, 20, 30t/ha and NPK 20:10:10 were 0, 150, 300, 450kg/ha. Agronomic Practices Among the agronomic practices carried out were land preparation/plot layout, planting, application of treatments, weeding. Land Preparation and Plot Layouts The land was ploughed and harrowed using tractor. Three blocks (or replicates) consisting of 36 blocks each were layout, each block will measure 2.6m x 2.25m and was separated from one another with a space of 0.5m. Alley pathways of 1m separated one block from another, and the total number of plots laid out in the entire experiment was108. Planting Maize seeds were sown on the plots at the rate of 1 seed per hole at a depth of 2-3cm, using 75cm x 15cm spacing as indicated by the first experiment. Procurement and Application of Organic Manure and NPK 20:10:10 Fertilizer Well-decomposed cattle dung was collected from cattle pen area, while poultry droppings was obtained from the battery cage system of poultry management of Delta State University, Asaba Campus. These organic manure were analyzed to determine their nutrient contents. NPK 20:10:10 fertilizer was obtained from Delta Agricultural Procurement Agency (DAPA), Ibusa.These amendment materials were incorporated into the plots according to the treatment as suggested by Olanikan (2006). Weeding: Weeding was done three times using hoe. Data Collection: Fourteen middle stands were used as sample population for data collection. Data collected was grain weight Asian Journal of Agriculture and Rural Development, 3(5) 2013: 234-248 239 of maize. The grain weight was measured using a weighing scale after harvesting and shelling at the end of the 16 th week. Statistical Analysis: Data collected were subjected to analysis of variance (ANOVA) and means were separated with Duncan Multiple Range Test (DMRT) according to Wahua (1999). Results Soil Physico-chemical Properties of the Experimental Site: The pre-physico-chemical properties of the experimental site is shown in Table 1. The result showed predominantly sand at the surface and this tends to decrease with depth of profile. Texturally, the soil of the experimental site is classified as sandy loam. The soil is acidic with pH of 6.2 in H2O and 5.6 in CaCl. The organic matter content and total nitrogen were low with values of 1.22 gkg -1 and 0.113 gkg -1 . The available P was high with value of 26.5 mgkg -1 . The exchangeable cations (Ca, Mg, Na and K) were equally low in status with values of 2.6cmolkg -1 for Ca 2+ and 0.9 cmolkg -1 for Mg 2+ . The value obtained for Na + was 0.57 cmolkg -1 , which was moderate while that for K + was 0.08cmolkg -1 , which was low. The CEC was 4.15, while ECEC was 5.6cmolkg - 1 , which were generally low. The exchangeable acidity was only trace for Al 3+ and characteristically low for H + with a value of 1.4 cmolkg -1 . Nutrient Content (%) of Organic Manure used in the Study The nutrient content of organic manure (poultry manure and cattle dung) used in the study is shown in Table 2. The values of N, P and K in poultry manure were significantly (P<0.05) higher than their values in cattle dung. With respect to N, poultry manure had 1.6% against cattle dung which was 0.4%. Also, poultry manure had 0.6% P while cattle dung had 0.2% P. The value for K was 0.8% in poultry manure, while it was 0.3% in cattle dung. Table 1: Physico-chemical Properties of Experimental Site Soil Property Value Interpretation Particle Size Distribution (%) Coarse sand 38 Fine sand 41 Silt 9 Clay 12 Texture ____ Sandy loam Ph H2O 6.2 Acidic CaCl 5.6 Acidic Organic Carbon gkg -1 0.71 Organic Matter gkg -1 1.22 Very low Total Nitrogen gkg -1 0.113 Low Available P (ppm) 26.5 Exchangeable bases (cmol/kg -1 ) Na + 0.57 Moderate K + 0.08 Very low Asian Journal of Agriculture and Rural Development, 3(5) 2013: 234-248 240 Ca 2+ 2.60 Low Mg 2+ 0.90 Low Cation Exchange Capacity 4.15 Exchangeable acidity (cmol/kg -1 ) Al 3+ Trace H + 1.4 Effective cation Exchangeable capacity (Cmol/kg -1 ) 5.6 Table 2: Nutrient (%) of Organic Manure Used in the Study Nutrient Content (%) Parameter N P K PM 1.6a 0.6a 0.8a CD 0.4b 0.2b 0.3b Legend: PM = Poultry Manure, CD = Cattle Dung, N = Nitrogen, P = Phosphorus Effects of Variety, Organic Manure and Inorganic Fertilizer on Grain Weight of Maize The responses of grain weight to variety, organic manure and inorganic fertilizer is shown in Table 3. Hybrid variety (9022-13) had higher grain weight of 2.10t/ha in 2008 and 2.30 t/ha in 2009, followed by open- pollinated variety BR9922-DMRSRF2 with 1.80 t/ha in 2008 and 1.91 t/ha in 2009, while Agbor local variety had the lowest grain weight of 1.20 t/ha in 2008 and 1.43 t/ha in 2009. The order of superiority in terms of highest cob weight was 9022-13 > BR 9922-DMRSRF2 > Agbor local. Plants that received inorganic fertilizer NPK 20:10:10 were superior in weight (2.30 t/ha in 2008 and 2.20 t/ha in 2009), followed by plants that received poultry manure (1.50 t/ha in 2009 and 1.73 t/ha in 2009), while plants that received cattle dung had the lowest weight. Increased application of manure or fertilizer resulted in increased gain weight. Among the varieties, plants that received NPK 20:10:10 fertilizer at the rate of 450kg/ha were superior with values of 3.10t/ha in 2008 and 2.76 t/ha in 2009, while unfertilized plants were inferior with values of 0.80 t/ha in 2008 and 1.27 t/ha in 2009. The effects of interaction (Table 4) indicated that variety, manure type, rate of application, variety * manure type, variety * rate were significantly (P<0.05) different and affected the changes in grain weight of maize, while manure type * rate, variety * manure type * rate were not significantly (P>0.05) different and did not affect changes in grain weight of maize in 2008 and 2009. Asian Journal of Agriculture and Rural Development, 3(5) 2013: 234-248 241 Table 3: Effects of Variety, Organic Manure and Inorganic Fertilizer on Grain Weight and Number of Grains per Cob of Maize in 2008 and 2009 Grain weight (tha -1 ) 2008 2009 Mean Variety 9022 – 13 2.10a 2.30a 2.20a BR9922-DMRSF2 1.80b 1.91b 1.85b Agbor Local 1.20c 1.43c 1.31c Nutrient Source PM 1.50b 1.73b 1.61b CD 1.30c 1.70b 1.50c IF 2.30a 2.20a 2.25a Rates of application (tons or kg/ha) 0 0.80g 1.27d 1.03e 10 1.10f 1.52c 1.31d 20 1.80e 1.98b 1.89c 30 2.10c 2.19b 2.14c 150 2.00d 2.06b 2.03c 300 2.80b 2.57a 2.68b 450 3.10a 2.76a 2.93a Means with the same letter(s) under the same column are not significantly different (P  0.05) using Duncan Multiple Range test (DMRT). Table 4: Effects of Interaction of Variety, Manure and Inorganic Fertilizer on Grain Weight of Maize in 2008 and 2009 Variety Nutrient Source Rate Grain weight (tha -1 ) Grain weight (tha -1 ) 9022-13 PM 0 1.0 1.2 10 1.5 1.7 20 2.4 2.4 30 2.6 3.0 Mean 1.9 2.1 CD 0 0.6 0.8 10 1.4 1.6 20 2.2 2.5 30 2.4 2.7 Mean 1.7 1.9 IF 0 1.5 1.4 150 2.5 2.4 300 3.2 3.8 450 3.7 3.9 Mean 2.7 2.9 BR9922- DMRSRF2 PM 0 0.8 1.3 10 1.3 1.6 20 1.9 2.1 30 2.2 2.0 IF (kgha-1) manure (tha-1) Asian Journal of Agriculture and Rural Development, 3(5) 2013: 234-248 242 Mean 1.6 1.8 CD 0 0.4 1.3 10 1.0 1.5 20 1.8 2.0 30 2.3 2.3 Mean 1.4 1.8 IF 0 1.3 1.4 150 2.1 2.4 300 0.7 3.8 450 3.4 3.9 Mean 1.9 2.9 Agbor Local PM 0 0.6 1.1 10 0.8 1.3 20 0.4 1.4 30 1.7 1.6 Mean 1.1 1.4 CD 0 0.5 1.3 10 0.7 1.4 20 1.0 1.5 30 1.6 1.6 Mean 1.0 1.5 IF 0 0.7 1.3 150 1.5 1.4 300 2.0 1.5 450 2.2 1.7 Mean 1.2 1.5 Variety * * Manure type * * Rate * * Variety x manure type * Ns Variety x rate * * Manure type x rate Ns Ns Variety x manure type x rate Ns Ns Legend: * = significant at 0.05 level of probability, Ns = not significant Discussion Soil Physico-chemical Properties of the Experimental Site The sandy loam texture of the experimental site may be attributed to the Parent Material (PM) from which the soil was formed and the climate of the area. The soil might be formed from sandstone and quartz parent materials. These impart sandy texture to the soils. The high sand content of the soil could be attributed to high content of quartz in the material (Brady and Weils, 1999). The weak acid nature of the soil of the area may be traced to the marked leaching of exchangeable bases resulting from the high rainfall associated with the environment and the dissociation of strong and functional group in the organic matter. This is in harmony with the findings of Esu (2001). Asian Journal of Agriculture and Rural Development, 3(5) 2013: 234-248 243 The low organic matter status of the experimental site could be attributed to the rapid decomposition of organic matter due to high solar radiation and moisture, this favours optimum microbial activities in the soil, It could also be attributed to the annual seasonal bush burning which tend to deplete organic matter accumulation in the soil (Landor, 199l). The low level of total nitrogen could be due to high temperature. It could also be attributed to leaching of’ nitrate by torrential rainfall prevalent in the environment (Olatunji et al., 2007). The high level of’ Phosphorus may be attributed to either of these reasons: (i) history of land use and cultural practices associated with the land use (that is, cropping of crops that do not take much P nutrient from the soil and the application of P organic fertilizers (Nnaji et al., 2002 and Nnaji, 2008). (ii) The parent material from which the soil was formed may be rich in P minerals (Brady and Weils, 1999). (iii) The soil may not be highly acidic as to cause high level of fixation (Brady and Weils, 1999, Isirimah et al., 2003 and Omokri et al., 2007). The low values of exchangeable cations may be attributed to the leaching of bases from the solum due to high rainfall characteristics of the area. The low action exchange capacity could be attributed to the PM from which the soil was formed, and low organic matter (OM) content of the soil. The PM from which the soil was formed may be poor in basic nutrients. FMANR (1990) noted that soils of the study area was dominated by Fe oxide and Kaolinites. These clay minerals are low in basic cations (Brady and Weils, 1999). The exchangeable acidity was low possibly because of the cultural practices associated with the land use (that is, previous use of amendments to improve soil condition and enhance crop yield. The results, generally, are in harmony with the findings of Osaretin et al. (2006), Olatunji et al. (2007) and the results of soil fertility evaluation in the region. It is also consistent with the findings of Nnaji et al. (2002) and Nnaji, (2008) which reported that the history of land use and cultural practices affect soil conditions and crop productivity. Nutrient Content (% dry matter) of Organic Manure used in the Study The values of N, P and K were higher in poultry manure than in cattle dung used in the study possibly because poultry manure, especially those produced in deep litter or battery cage house, have more concentrated nutrient content compared with other types of animal manure. This is similar to the findings of Sharpley and Smith (1995), Lombin et al., (1991), and Brady and Weils (1999) who reported that among the different sources of organic manure which have been used in crop production, poultry manure was found to be the most concentrated in terms of nutrient content. It is also in harmony with the findings of Subedi and Gerung (1991) and D1PA (2006) who reported that poultry manure has higher levels of N. P and K than cattle dung. It is also consistent with the findings if Ibeawuchi et al., (2007) who reported higher levels of N. P and K in plots treated with poultry manure than in plots treated with other nutrient sources. Asian Journal of Agriculture and Rural Development, 3(5) 2013: 234-248 244 Effects of Variety, Organic Manure and Inorganic Fertilizer on Grain Weight of Maize The superiority of hybrid variety 9022-13 over other varieties could be attributed to the yield advantage of hybrid varieties over other varieties. This is similar to the findings of Kim (1997) and Olakojo et al. (1998) who reported that hybrid varieties of maize have yield advantage of 25% and 50% over the best open pollinated varieties in Nigeria. It also agrees with the report of Obi (1999) that hybrid maize varieties possess such specials qualities as high yield, disease resistance, uniformity of flowering and ear placement, as well as ease of harvesting using combined harvester. The higher grain weight obtained from plants that received NPK 20:10:10 fertilizer over other plants may be attributed to its faster rate of mineralization and release of nutrients for plants’ use. This is similar to the findings of Abiola and Aiyelaagbe (2005) who reported that inorganic fertilizer performed better than organic manure because inorganic fertilizer made their minerals easily available for plants’ use. It is also similar to the findings of Akintoye and Olufolaji (2005) that made such reports on the growth and yield of cayene pepper. Higher rate of application of manure or inorganic fertilizer resulted in higher cob weight of maize possibly because of increased availability of nutrient elements in the soil. This is similar to the findings of Olarewaju and Showemimo (2003); Aliyu and Olarewaju (1996) who reported that the number of fruits, fruits yield and size increased as the nitrogen and phosphorus fertilizer levels increased in the soil pepper. Plants that received poultry manure had higher grain weight than plants that received cattle dung. This supports the report of Lombin et al. (1991) which rated poultry manure best among the different source of organic manure because its nutrient content are more concentrated and supplied in readily absorbable form. Conclusion and Recommendations The study was carried out to evaluate the response of grain weight of maize to variety, organic manure and inorganic fertilizer in Asaba area of Delta State. It was a factorial experiment carried out in a Randomized Complete Block Design (RCBD) with three replicate. The result showed that hybrid variety 922-13 was superior in grain weight of maize and was therefore recommended to be grown in the study area. Also, it was recommended that 450 kgh a-1 of NPK 20:10:10 which resulted in higher grain weight be adopted by farmers who prefer mineral fertilizers in maize production. References Abiola I. O. and Aiyelaagbe I. O. (2005). 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