Soil testing is key to soil fertility management as it serves as a fertilizer application guide to farmers, scientists and consultants. It gives information on soil nutrient status and its supplying capacity. Laboratory (LB) procedures have been the most reliable approach for soil nutrients analyses. However, it is costly and nonpoint. Thus, the use of in–situ testing kit emerges and becomes prominent. Notwithstanding, applicability of soil testing kit must be validated by laboratory test. This work aimed to examine the reliability/suitability of Soil Testing Kit® Transchem (SK) in determining selected soil nutrients in Sahel Savannah, Nigeria. Twentyfive replicate soil samples were collected from 12°47’86’’-12°20’96’’N and 4°38’37’’-4°188’02’’E, Kebbi State Nigeria and used to test soil pH, N, P, K and soil organic carbon (SOC) by SK and LB. The SK uses colour chart and comparator for rating nutrients status qualitatively into; low, medium and high and up to very high for P. The LB results were transformed to qualitative data by corresponding the values with soil rating standardinto low, medium and high. To perform statistics, weighting was done by assigning weight load to each category; low = 1, medium = 2 and high = 3. The two methods were compared using t-test, regression and descriptive analyses. Results showed non-significant difference between the two methods for soil contents of N, P and K. However, SK poorly estimated soil pH and SOC. Correlation and regression coefficients (r = 0.915 and R2 = 0.838, respectively) indicated reliability of the SK. It is concluded that SK can be reliably used for N, P, and K but not soil pH and SOC estimation for soils in Sahel savannah of Nigeria.

Operation of gamma spectrometry requires intensive monitoring of gamma ray fluxes. When a radioactive intense source is placed close to a crystal detector, it becomes saturated as a result of detector dead time. On the contrary, when placed far away, there is loss of count statistics. For this reason, optimal position for placing the source has to be investigated. With the improvement in the instrumentation of radiation detection applications over the years, high count rate measurement accuracy is more crucial than ever. This is due to periodic measurement and new correction models for dead time. The aim of this study is to examine the performance of two gamma spectroscopic systems. The source detector distance dependence on dead time, peak-to-compton ratio, overall amplifier gain, FWHM, and voltage variation were investigated using American standard procedures (ANSI/IEE -325). Measurements were performed at five (5) different distances of detector cap for four (4) point sources (Co-60, Eu-152, Cs-137 and Ba-133). Source-to-detector distance at 25 cm was improved to avoid summing coincidence and dead time correction. The results obtained at 25 cm showed that the dead time was found less than 1% as compared to 4 cm. This will describe the stability of dead time. It also indicated that for both detectors the rise in biased voltage will yield a good resolution at 1332.5 KeV. This study is significant as it provides information to ensure that detectors are kept at optimal distance to achieve good dead time.

Ground magnetic data were acquired, analysed and interpreted for shallow archaeological investigation at Sungai Batu, Lembah Bujang, Kedah, Malaysia. The objective is to locate buried archaeological remains, typically in form of baked clay bricks in the surveyed area. Magnetic field intensity data were acquired using G-856 proton type magnetometer at 1 m by 2 m grid spacing. During the data acquisition, suitable base station was established 50 m away from the study area, to take readings at 1-min interval for diurnal data correction and regional-residual separation. Residual field intensity values obtained were in the range of-25 nT to 177 nT. The values were generally divided into two main classes: low magnetic (< 38 nT), and high magnetic (> 38 nT). The data were gridded and contoured using Oasis Montaj software to obtain the magnetic residual field intensity map. The gridded data were reduced to magnetic equator to shift peaks of anomaly over centres of magnetic source. Automatic gain control filter was thereafter applied to enhance signal in regions of low field variation and to suppress signal in regions with high field variation. The process revealed sharp anomalies interpreted as signatures of baked clay bricks at the western and eastern parts of the area.

The study aimed at comparing the resolution and effectiveness of three-electrode arrays (Wenner-α, Wenner-β, and Wenner-γ) in the 2D Electrical resistivity method using Numerical analysis of geological models. Three synthetic geological models that simulate block-one dyke and water layer were generated using RES2DMOD software. The inversion used for the geological models was based on smoothness-constrained least-square inversion which was carried out with RES2DINV. The inversion results were imputed into surfer11 software to examine the image resolution, thereafter absolute percentage error (APE) was calculated to measure the effectiveness of the arrays. The result for the block-one model shows that the Wenner-β array has an APE of 14.45%, the Wenner-α array has an APE of 32.67%, and the Wenner-γ array with an APE of 29.15%. Similarly, for the dyke model, the Wenner-α array, Wenner-β array, and Wenner-γ array have an APE of 69.61%, 57.43%, and 45.49% respectively. However, the results for the water layer model show that the Wenner-α array has an APE of 17.11%, the Wenner-β array has an APE of 12.16%, and that the Wenner-γ array has an APE of 16.21%.  Wenner-α is expected to produce an image with the best resolution having the highest APE, henceforth APE suggests the resolution capacity of an array.