This study presents an empirical analysis of the impact of capital flight on tax revenue in Nigeria. We made use of secondary data collected from the Central Bank of Nigeria Statistical Bulletin of various issues, Federal Inland Revenue Services and National Bureau of Statistics. The empirical measurement covers the sample period between 1980 and 2015. An Ordinary Least Square, Augmented Dickey-Fuller unit root test, Error Correction Mechanism and Co-integration test was adopted in the study. The results revealed that the Gross Domestic Product has a significant effect in the positive direction, while capital flight and inflation rate have a significant effect in the negative direction. The study recommended that the Federal Inland Revenue System, the department saddled with the responsibility of tax collection, should review the tax system and policies with the aim of plugging loopholes in the existing tax system thereby preventing organizations from evading and avoiding taxes.

We evaluated the effect of 4000 mg zinc oxide (ZnO, 99%, 30 nm) nanoparticle on the physicochemical and microbiological properties of organic manure amended ultisol and loam soil cultivated with Arachis hypogaea using standard methods. The results indicate varying effects on the physicochemical properties in relation to the soil type. The pH of the control ultisol at 7.85 ± 0.17 and 8.3 ± 0.12 in the amended ultisol whereas, the control loam was 7.15 ± 0.17 and 7.41 ± 0.11 in the amended soil indicating 1.06- and 1.04-times higher difference than the controls respectively.  Phosphorus concentration at 57.82 ± 0.54%, 50.81 ± 0.22% and 55.97 ± 0.04%, 59.97 ± 0.02% was 1.14 times lower in the ZnO amended ultisol and 1.07 times higher in amended loam soil compared to the respective controls. The organic matter content in the control and amended ultisol was 2.28 ± 0.32% and 0.91 ± 0.02%, 3.68 ± 0.36% and 0.36 ± 0.02% in the control and amended loam soil. The concentration of nitrate in the control ultisol was 0.05 ± 0.01% and 0.03 ± 0.01% in the amended soil. The nitrate in the control loam soil was 0.08 ± 0.01% relative to 0.02 ± 0.01% in the treated soil and these differences were significant at p = 0.05. The concentration of nutritive salts was reduced and in contrast iron, copper, exchangeable acids, exchange capacity, clay and silt increased in the amended soils. Further to this, heterotrophic ammonia and nitrate-oxidizing bacterial population were inhibited in the amended soils and denitrifying organisms were stimulated. The organisms were members of the genera Pseudomonas, Xanthobacter, Enterobacter, Bacillus, Lactobacillus, Citrobacter, Nitrosomonas, Agromyces and Rhizobium. ZnO nanoparticles altered the soil physicochemical properties which exacerbated the negative effect on microbial abundance and varied with the soil type.

We investigated the influence of soil properties on the availability or otherwise of micronutrients in agricultural soils impacted by inorganic and organic manures in the South-South Area of Nigeria. The levels of pH, organic matter (OM), cation exchange capacity (CEC), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) in the understudy soil were examined. The measured pH, OM, CEC, Cu, Fe, Mn and Zn levels revealed: 6.04±0.49, 17.68±4.78 %, 7.97±0.81 Cmolkg-1, 5.27±0.82 mgkg-1, 232.49±16.01 mgkg-1, 109.30±9.85 mgkg-1, and 8.40±1.15 mgkg-1, for pH, OM, CEC, Cu, Fe, Mn, and Zn, respectively. The values were within the acceptable limits set by national and international standards. The study revealed variable relationships between the soil properties and micronutrients in the studied soils at p < 0.05. Soil pH exhibited a strong negative association with all the micronutrients except Zn. However, a strong positive correlation (p< 0.10) was recorded between pH and Zn. OM showed a significant positive correlation (p< 0.10) with Fe, a weak positive correlation with Zn, and a non-significant negative correlation (p< 0.10) with Cu and Mn at p < 0.10. CEC exhibited a fair positive association with Fe and Zn, and a non-significant negative correlation (p< 0.10) with Cu and Mn. The principal component analysis (PCA) identified a combination of anthropogenic and natural impact and the impact of agrochemicals applied as the major factors influencing the properties determined in the studied soils. The study concluded that soil properties have a strong influence on the availability or otherwise of micronutrients in the soil.

Abstract. Enyiukwu DN, Chukwu LA, Bassey IN. 2020. Nutrient and anti-nutrient compositions of southern pea (Vigna unguiculata) and mung bean (Vigna radiata) seeds grown in humid Southeast Nigeria: A comparison. Trop Drylands 3: 41-45. Pulses are important components of African cuisines. Cowpeas (Vigna unguiculata (L.) Walp.) are commonly consumed in most parts of Nigeria, but mung bean (Vigna radiata (L.) Wilczek) though new in the agro-landscape, is gradually gaining popularity. Its popularity is based on the speculation that it is of higher nutritional content than cowpeas. This work evaluated the nutritional compositions of seeds of both pulse crops grown in humid southeast Nigeria using classical and spectrometric analysis. Results obtained from the study showed that the mean proximate compositions of mung bean (17.70%) did not statistically (P?0.05) differ from that recorded for cowpea seeds (17.30%). However, irrespective of the high magnesium content (62.39 mg g-1) of mung bean, the mean mineral nutrients in cowpea (270.69 mg g-1) is grossly higher than (145.58 mg g-1) recorded in mung bean due largely to high presence of potassium (1.29 g 100 g-1) in cowpeas than in the former. Data from this study also showed that higher contents of flavonoids (11.31 mg g-1) make the mean content of phytochemicals in mung bean (4.21 mg g-1) to be slightly higher than but statistically (P?0.05) at par with that obtained in cowpea seeds (3.67 mg g-1). Generally, the nutrient contents in mung beans are not substantially higher than that of cowpea and vice versa. It is therefore recommended based on data obtained from this study that both be used to supplement each other in African diets due to their differential contents of flavonoids, magnesium, and potassium for better well-being and health.

Abstract. Enyiukwu DN, Nwaogu GA, Bassey IN. 2020. Association of cowpea (Vigna unguiculata L. Walp.) (var. Ife Brown) with Colletotrichum destructivum O'Gara: A special reference to nutrients lost by the host. Cell Biol Dev 4: 41-46. Cowpea or southern pea (Vigna unguiculata L. Walp.) is an important African grain and leafy vegetable. Anthracnose caused by C. destructivum represents a major biotic drawback to the profitable production of cowpeas in the incontinent. The disease culminates in the loss of grain yield, produce quality, and nutritional values of the crop. This work assessed and quantified the nutrients lost from the aerial organs of cowpea (var. Ife Brown) challenged by anthracnose disease in the field and storage 4 weeks after inoculation (WAI) by classical and spectrometric analyses. The results showed that the disease affected the nutrient contents of the inoculated crop's aerial organs, decreasing the mean quantities of all proximate constituents and major mineral nutrients such as calcium and phosphorus in the test plant materials. Amongst the aerial organs, fat was the most depleted nutrient (36.30%), followed by protein (28.52%), carbohydrate (26.67%), and crude fiber, with 20.04%, was the least. Generally, the highest mean loss of proximate nutrients due to anthracnose disease per organ of the test crop of 27.97% was recorded in the leaf sample, followed by 22.13% in the seeds and 18.03% in the husks was the least. Similarly, the highest mean mineral loss of 42.63 mg 100 g-1 occurred in the husks, followed by the stem (26.14 mg 100 g-1), while the seed recording (15.41 mg 100 g-1) was the least. Controlling this important fungal disease of the crop will undoubtedly result in better leaf, grain, and haulm quality, which will rub off as improved farm economy and public health in the continent.