Effects of phosphate rock application on dry matter yield and phosphorus recovery of maize and cowpea grown in sequence

The study was conducted in a greenhouse at the Institute of Agricultural Research and Training (IAR&T) Ibadan, Nigeria to evaluate the influence of P source, rate and frequency on dry matter yield of maize and cowpea grown sequentially in three soil types. Three sources of P: Ogun phosphate rock (OPR:20.2% P2O5); Crystallizer super (CS: 31.4% P2O5) and Single super phosphate (SSP: 18.0% P2O5); Four rates (0, 20, 40 and 60 kg/ha P2O5) and Two frequencies (regular and alternate application) were studied on three soil types (Ilora-Udipsamment; Ibadan- Arenic Haplustalf and Epe - Aquic Arenic Haplustalf soils). The experiment was laid out in a split-split plot arrangement, using completely randomized design. Phosphate application significantly enhanced dry matter yields of maize and cowpea. Single super phosphate (SSP) gave a higher total biomass than the phosphate rocks (PR). On Ilora soil with the regular application frequency in the first cropping, maize total biomass was increased by SSP from 4.23 g/plant to 8.20, 9.25 and 9.72 with 20, 40 and 60 kgP/ha while it was increased to 6.78, 6.26 and 6.34g with OPR but to 6.88, 7.60 and 7.15 g with CS. Cowpea yields were increased from 2.12 g/plant to 3.28,4.04 and 3.36 g with SSP; to 3.34, 3.27 and 2.61 with CS and to 2.59, 2.78 and 2.39 g with OPR. On Ibadan soil, maize biomass yield ranged between 6.13 and 6.37 g with OPR; between 7.22 and 7.56 with CS and between 6.80 and 10.45 g with SSP. Cowpea yields were between 6.54 and 7.81 with OPR; between 5.70 and 6.80 with CS and were between 6.59 and 8.94 with SSP. Both Ogun and crystallizer super PRs gave comparable dry matter yields of maize and cowpea as single super phosphate. Best growth performance was observed with application of 60 kg/ha in all the soils. Significant treatment effects in shoot, root and total dry matter yields of maize and cowpea were obtained with 60 kg P/ha. Alternating maize with cowpea gave a higher total plant biomass than continuous maize. Regular frequency of application was superior to alternate frequency of application. Cumulative apparent P recovery of maize and cowpea at the end of final cropping was maximal with 20 kgP/ ha SSP in the three soils. It had 75, 80 and 70% recoveries for Ilora, Ibadan and Epe soils respectively

Geochemistry and mineralogy of Ogun phosphate rock

Suitability of direct application of phosphate rock as low cost phosphorus fertilizer for crop production must be environmentally safe. Four pellets of Ogun phosphorites labeled OG1, OG2, OG3 and OG4 were randomly selected and subjected to petrographic, X-ray diffraction and X- ray fluorescence analyses. Petrographic results revealed two textural forms: nodular (OG1 and OG3) and granular (OG2 and OG4). Characteristic features like fine grains of phosphorites, geopedal texture with heavy iron staining were found in nodular form while presence of shell fragments and bioclastic materials with burrows were observed in granular form. The diffractogram of different pellets showed poorly crystalline mineral, flourapatite was identified as the major apatite mineral. X-ray fluorescence results showed wide variations in elemental composition among the different forms of Ogun phosphorites. In nodular phosphorites (OG1 and OG3), apatite content were 31.28 and 30.20% P2O5 respectively, Granular phosphorites (OG2 and OG4) contain 19.73 and 11.12% P2O5. The alkali metals K2O and Na2O are variable and low showing its suitability as P source because minimal salt is added to the soil. Radionuclides present have low values (U 19 to 29 ppm; Th 5 to 13 ppm; Ni 41 to 80 ppm) indicating its environmental security.Key words: Phosphorus, phosphorites, Ogun phosphate rock, x-ray fluorescence analysis, x-ray diffraction analysis, petrography analysis

Rural-Urban Differences in Maternal Responses to Childhood Fever in South East Nigeria

Childhood fevers due to malaria remain a major cause of morbidity and mortality among under-five children in Nigeria. The degree of vulnerability perceived by mothers will affect their perception of the severity and threat of their child's fever and the patterns of health care use. This study was undertaken to compare maternal responses to childhood fever in urban and rural areas of Enugu, south east Nigeria.Data was collected with pre-tested interviewer-administered questionnaires from 276 and 124 urban and rural households respectively. In each household, only one woman aged 15-49 years who had lived in each of the urban and rural communities for at least one year and had at least one child less than 5 years old was interviewed. Malaria was mentioned as the commonest cause of childhood fevers. Rural mothers were more likely to recognize danger signs and symptoms than urban mothers. Rural mothers use more of informal than formal health services, and there is more home management of the fever with urban than rural mothers. Chloroquine, ACT, SP and Paracetamol are the main drugs given at home for childhood fevers, but the rural mothers were more likely to use leftover drugs from previous treatment to treat the fevers than urban mothers. The urban respondents were also more likely to use a preventive measure. Urban mothers sought actions faster than rural mothers and the total cost of treatment was also higher in urban areas.Both urban and rural mothers are aware that malaria is the major cause of childhood fevers. Although rural mothers recognize childhood fever and danger signs better than urban mothers, the urban mothers' responses to fever seem to be better than that for rural mothers. These responses and differences may be important for geographical targeting by policy makers for malaria interventions

Soybean performance (Glycine max (L) Merr) on tropical soils with nitrogen and phosphorus fertilization

Pot trial was conducted to investigate the effects of soil types, nitrogen and phosphorus application on the yield, and nodulation and nutrient uptake of soybean grown on tropical soils. Results showed that forest soils produced higher dry matter yield, pod number, seed number, nodule number, and nodule weight at 6 and 12 weeks after planting (WAP) than savanna soils. The increment values were averagely 152%, 325%, 275%, 105% and 45% respectively at both periods. The uptake of K, Ca and Sulphur were greater in savanna soils, while forest soils had 19% and 41% increase in the uptake of Nitrogen and Phosphorus, respectively above savanna soils. The interaction between soil type and nitrogen or phosphorus also indicated that forest soil with 25kgNha-1 or 50kgPha-1 had significantly higher values for the soybean performance parameters investigated. Soybean grown on forest soil from Odeda I (Typic kandiudalf) had higher seed-weight and number of pods; 2% and 57%, respectively above that from savanna soil (Ayetoro II, Typic kandiudult) both at 25kgNha-1 fertilization. Forest soil from sedimentary rock/Alluvium (Ikorodu 1(and those from basement complex rock (Odeda I) produced soybean that had higher values in nodule weight and uptake of phosphorus at 50kgPha-1 compared to savanna soil from sedimentary rock. The incremental values were 59% and 79% respectively. In general, the combined application of 25kgNha-1 and 50kgPha-1 appeared optimum for soybean cultivation. Key words: Tropical soil; soybean performance; nitrogen and phosphorus fertilizers Moor Journal of Agricultural Research Vol.4(2) 2003: 170-17

Nitrogen-use Efficiency of Maize Genotypes under Weed Pressure in a Tropical Alfisol in Northern Nigeria

A split - split plot experiment in a randomized complete block design with three replicates was established at Samaru (Typic Haplustalf) in 2002 and 2003 rainy seasons to investigate the response of four low nitrogen tolerant maize (Zea mays L.) cultivars (Oba super II, Low N pool C2, TZB-SR and ACR 8328 BN C7) to nitrogen fertilizer and weed pressure. Maize grain yield, nitrogen-uptake, utilization and use efficiency were significantly higher in Oba super II and Low N pool C2 followed by ACR 8328 BN C 7 and least in TZB -SR. At the application rate of 90 kg N.ha-1, 68 kg N.ha-1 were recovered in maize shoot while weeds uptake of N was 15.98 kg.ha-1. With the application of 30 kg N.ha1, weed uptake was 28.38 while maize shoot uptake was 23.35 kg N.ha-1. Generally, fertilizer addition enhanced the competitive ability of maize. The nitrogen-use efficiency of the maize genotypes was reduced due to weed interference while there were no differences in the residual soil nitrate among nitrogen rates and genotypes, partly due to the morphology of the site

Yield and yield components of tropical maize genotypes as affected by drought and weed stresses

No Abstract.Nigeria Agricultural Journal Vol. 38 2007: pp. 31-3

Appraisal of some nitrogen indices for predicting nitrogen need of maize

Field experiments were conducted for two years on 20 farmers' fields to appraise some N forms as indices for predicting N need of maize crop in some southwestern Nigeria soils. The total-N organic-N, exch. NH4, fixed-NH4 and NO3-N in the 0-20 cm depth ranged from 300-1400, 249-1197, 10-62, 15-122 and 9-42 mg kg-1 respectively. All the N forms are significantly related to soil organic matter. Although all the N forms gave positive and significant relationships with relative yield, the most important predictor variable was NO3 –N in 0-45cm soil depth (R2=0.94). The critical level of the residual NO3 within this soil depth was established at 46.0 mg kg-1. Six of the sites fell within high N class while the other 14 sites fall within low N class. The probability of obtaining response to N application is higher in the latter than in the former sites. Nigerian Journal of Soil Science Vol. 15 2005: 123-12

Utilization of maize (Zea mays) cob as an adsorbent for lead (II) removal from aqueous solutions and industrial effluents

Maize cob was used as an adsorbent in order to evaluate its potential for the removal of lead from aqueous solutions and effluents from battery and paint industries with Dowex (synthetic resin) as control. Experimental data were analyzed in terms of Freundlich isotherm model. Equilibrium was attained at 2 h and adsorption rate constants for maize cob and dowex were 7.26 x 10-2 and 7.58 x 10-2 min-1, respectively. Equilibrium pH value was 6; shaking at 150 rpm enhanced adsorption with maximum adsorption by both adsorbents in battery and paint effluents. Optimal weight at equilibrium for the adsorbents in Pb2+ solution was 16 mg/L of solution. Pb2+ removal by maize cob from battery effluent was 99.99% while it was 47.38% for Dowex. Corresponding values from paint effluents were 66.16 and 27.83%. The study concludes that maize cob has great potentials to remove Pb2+ from industrial effluents

Utilisation of biomaterials as adsorbents for heavy metals’ removal from aqueous matrices

Globally, the available amount of freshwater is unevenly distributed due to problems associated with climate change, inefficient water management and pollution. This has led to increased demand for water worldwide. Heavy metals, in particular are a group of pollutants (mostly from domestic, agricultural and industrial activities) of major concern in the aquatic environment due to their toxicity. Existing technologies for heavy metals’ removal from waters and wastewaters are often ineffective (especially at environmental levels), expensive and unavailable in developing countries. A higher percentage of these pollutants are therefore being released into aquatic ecosystems by manufacturing facilities in these nations. The need to find alternative inexpensive and effective methods for heavy metals abatement from waters becomes inevitable. Biosorption is an emerging field in this regard and has great potentials for application in developing economies. It involves the use of living or non-living biological materials for pollutants’ removal from aqueous solutions and industrial effluents. This paper therefore reviews developments in the use of biosorbents for the remediation of waters and wastewaters