ARID ZONE JOURNAL OF ENGINEERING, TECHNOLOGY AND ENVIRONMENT

1-5

Authors: U. A. Kawuyo, A. A. Lawal, J. A. Abdulkadir, Z. A. Dauda

A locally developed grain milling machine was evaluated using maize (Sammaz - 12 variety) and millet (Lake Chad Dwarf variety) at different moisture range of 8.3% to 24.6% and 6.4% to 27.2% (db) respectively. The performance indices considered for the evaluation of the machine were milling efficiency, machine efficiency and milling rate. The results obtained were subjected to statistical analysis. The results showed that all the parameters evaluated decreased with increase in moisture content for both grains used in testing evaluating the performance of the machine. It was found that, the milling efficiency and milling rate decreased from 86.3% to 40% and 20.4 to 12.5kg/h for maize respectively and 89% to 26.6% and 23.4kg/h to 12.1kg/h for millet respectively as the moisture content was increased. Statistical analysis showed significant (P < 0.05) differences between the crop moisture content and milling efficiency and machine efficiency. The milling rate was not significantly affected by the moisture content for both grains used in the study.

15-30

Authors: B. S. U. Ibn Abubakar, N. Abdullah, A. Idris, M. P. Zakaria, M. Y. Shokur

Biodegradation and kinetics of Pyrene (Pyr) degradation by a mixed culture previously isolated from hydrocarbon-polluted soil were conducted. Preliminary investigation on environmental factors affecting the degradation of Pyr such as temperature, pH and concentrations of Pyr was performed. These factors were optimised and established in aqueous experiments. In order to develop kinetics of Pyr degradation, an optimum temperature of 30oC and pH of 7.0 was used. Biodegradation kinetics was carried out, at first, using higher concentration between (100-700 ppm) as sole source of carbon in mineral salt medium (MSM) supplemented with 0.1% yeast extract. The result indicated that a range of concentration between (100-700 ppm) inhibits the performance of the mixed culture. A concentration range between (10-100 ppm) did not inhibit the growth of the mixed culture. A First-order rate constant, k was higher (0.0487 mg/lh) with a substrate concentration of 20 ppm than other concentrations. The average degradation rate constant is 0.0029 mg/Lh for all the concentrations tested. This indicated that the mixed culture could degrade over 0.0696 ppm of Pyr per day. It also confirmed that kinetics of microbial degradation was partially fitted into Monod model. The data can be used to estimate biodegradation of Pyr by a mixed culture and preliminarily estimation of degradation rates.

38-46

Authors: J. M. Dibal, A. U. Bashir, N. A. Abubakar, B. Baraya

Erroneous choices of furrow irrigation characteristics trigger soil erosion with several negative impacts. Soil erosion and sediment yield in furrow irrigation has not been fully evaluated in Samaru-Zaria. This study sought to establish the interactive effects of irrigation stream sizes (2.5, 1.5, and 0.5 l/s); furrow lengths (90 and 45 m); and furrow widths (0.75 and 0.9 m) randomized in a split-plot design on soil erosion, growth, and yield of maize (Zea mays L.). The 90- and 4-m long furrows were herein referred to as long and short furrows respectively, while the 0.75- and 0.9-wide furrows were termed narrow and wide furrows for convenience sake. The field experiment involved irrigating maize on the normal straight furrow irrigation method on a sandy loam soil in the Irrigation Research Farm of Institute for Agricultural Research (I.A.R), Samaru-Zaria, in 2009/2010 and 2010/2011 dry irrigation seasons. Maize plants irrigated at 2.5 l/s on long narrow furrows were most stunted (118.396 m) while irrigating at 1.5 l/s in long wide furrows produced tallest maize plants (169.034 m). Irrigating at 2.5 l/s in long narrow furrows delayed days to 50 % tasseling (77.632 days) and days to 50 % plant maturity (79.125 days). Highest average sediment concentration (41.697 g/l) and runoff volume (147.861 ltr) were recorded in short narrow furrows irrigated at 2.5 l/s. The long narrow furrows irrigated at 2.5 l/s produced largest soil erosion (0.603 t/ha). Best grain yield (5.19 t/ha) was achieved in long wide furrows irrigated at 1.5 l/s. The severity of soil erosion and its impact on crop production were greater in long narrow furrow irrigated at 2.5 l/s. Irrigation at 1.5 l/s in long wide furrows trimmed down soil erosion and better maize growth and yields. Furrow irrigation should be designed and operated professionally to avert ecological deterioration, and sustain soil’s quality and crop productivity.

54-65

Authors: A. Dauda, K. D. Maina

An appropriate tillage method is necessary to create an optimum seed bed condition for optimum crop growth and yield. Two-year field experiment was conducted in 2013 and 2014 to investigate the effects of different tillage methods on the physical properties of sandy loam soil, growth and yield of water melon (Citrullus vulgaris) in a semi-arid environment. The Tillage treatments were disc ploughing plus disc harrowing (DP+DH), double disc ploughing (DDP), double disc harrowing (DDH), disc ploughing (DP) and disc harrowing (DH) as minimum tillage (MT) and zero tillage (ZT) and direct drilling method (control). The watermelon seeds were Planted manually placing three (3) seeds per hole at an interval of 1.5m along the rows and 50cm between the rows at an average depth of 5cm. The treatments were laid in a randomized complete block design (RCBD) with four replications. Results showed that disc ploughing + disc harrowing (DP+DH) was found to be more appropriate and profitable tillage method in improving soil physical properties and growth and yield of water melon in a sandy loam soil. Watermelon yield, fruit weight (FW), fruit length (FL), fruit diameter (FD) and leaf area index (LAI) were significantly influenced (P=0.05), but influence of tillage treatments were not significant on the number of fruit per plant (NFPP). A numerical value of 31.0t/ha, 26.0, 5.4kg, 29.0cm, and 33.8cm were recorded for maximum crop yield, NFPP, FW, FD and FL respectively in DP+DH-treated plots. For zero tillage (ZT) treatment, maximum of crop yield and NFPP were 26.5t/ha and 20.0 respectively. Thus for enhanced growth and yield of watermelon, DP/DH would be more preferable. The orthodox method of zero tillage is out rightly discouraged

77-85

Authors: M. S. Abubakar, S. A. Bello

Anaerobic digester is a physical structure that provides a conducive environment for the multiplication of micro-organisms that degrades organic matter to generate biogas energy. Energy is required in agriculture for crop production, processing and storage, poultry production and electricity for farmstead and farm settlements. It is energy that propels agricultural mechanization, which minimizes the use of human and animal muscles and its inherent drudgery in agriculture. The energy demand required to meet up with the agricultural growth in Nigeria is high and growing every year. In this study the design and fabrication of an anaerobic digester was reported which is an attempt to boost energy requirement for small and medium dryland farmers in Nigeria. The design of the digester includes the following concept; the basic principles of anaerobic digestion processes, socio-economic status of the dryland farmers, amount of biogas to be produced. Finally, the digester was fabricated using locally available raw materials within the dryland area of Nigeria. At the end, preliminary flammability test was conducted and the biogas produced was found to be flammable.

97-110

Authors: M. Abdulkadir, A. L. Bukar, B. Modu

The conventional maximum power point tracking (MPPT) techniques can hardly track the global maximum power point (GMPP) because the power-voltage characteristics of photovoltaic (PV) exhibit multiple local peaks in irregular shadow, and therefore easily fall into the local maximum power point. These conditions make it very challenging, and to tackle this deficiency, an efficient Iteration Particle Swarm Optimization (IPSO) has been developed to improve the quality of solution and convergence speed of the traditional PSO, so that it can effectively track the GMPP under irregular shadow conditions. This proposed technique has such advantages as simple structure, fast response and strong robustness, and convenient implementation. It is applied to MPPT control of PV system in irregular shadow to solve the problem of multi-peak optimization in partial shadow. In order to verify the rationality of the proposed algorithm, however, recently the dynamic MPPT performance under varying irradiance conditions has been given utmost attention to the PV society. As the European standard EN 50530 which defines the recommended varying irradiance profiles, was released lately, the corresponding researchers have been required to improve the dynamic MPPT performance. This paper tried to evaluate the dynamic MPPT performance using EN 50530 standard. The simulation results show that iterative-PSO method can fast track the global MPP, increase tracking speed and higher dynamic MPPT efficiency under EN 50530 than the conventional PSO.

140-148

Authors: A. M. Kundiri, B. A. Umdagas, M. B. Oumarou

This study characterized and analysed the constituents of the leachates from four uncontrolled and unlined waste dumpsites in Maiduguri, North eastern Nigeria. The leachate samples were carefully collected from waste dumpsites without any conventional collection equipment and transferred to the laboratory for analysis. The ionic concentration, pH, electrical conductivity (EC), and total dissolved solids (TDS) were determined using a conductivity meter, potassium and sodium by photometer; chlorine and calcium by titration method, BOD was computed from dissolved oxygen as determined by Winkler’s method and the UNICAM 969 Atomic Absorption Spectrophotometer was used to measure the cation and anion concentrations. The pH and TDS values ranged between 8.19 to 11.32, and 208 to 7460 mg/l respectively indicating a reduction in the palatability of groundwater below the waste dumpsites due to the presence of large amount of anions and cations. The analysis has so far indicated that the concentration of Fe ion was highest followed by that Pb, Zn, Cr, Mn and Cu ions respectively. This is attributed to the presence of large iron-base materials such as metallic construction materials, fluorescents lamps, electrical appliances, paint products, batteries and wood preservatives. To avert the health-related hazards as a consequence of groundwater contamination by leachates, it is imperative for the Borno State Environmental Protection Agency (BOSEPA) to urgently address waste management practices. This could be achieved by employing the environmental engineering principles of waste management as panacea to the threat posed by leachate and other groundwater contaminants in the study area.