This study evaluated the responses of selected soil chemical properties and heavy metals as affected by sewage dump in Abakaliki southeastern Nigeria. A reconnaissance survey of the study area was carried out and the following dump soils were selected: A (Abattoir sewage dump), B (Cassava sewage dump), C. (Domestic sewage dump) and D (Control – Non-sewage dump soil). Five replicate auger soil samples were collected I m away from each dump at 0 – 30 cm soil depth and used for the determination of soil ph, Organic C, total N, available P, exchangeable bases, Cu, Pb, Cd, Zn and Cr. The results showed that sewage improves soil chemical properties. The heavy metals observed were also higher in sewage dump soils than the control. Similarly, the soil study was sandy loam. Therefore, stringent measures must be taken while dumping sewage in these soils soil since the soil can easily contaminants from sewage to underground water.
The status and spatial variability of soil properties across agrarian communities in Yakurr Local Government Area, Southeast Nigeria were assessed and soil management strategies suggested for limiting soil properties. Nine communities were identified within the study area and soil samples collected from young fallow lands measuring 40 m by 40 m at depths of 0 – 20 cm and 20 – 40 cm to represent surface and subsurface soils respectively. The interpolation of the area was done using the deterministic methods of inverse distance weighting (IDW) in ArcGIS 10.2.2 software. The soils were sandy loam to loamy sand with the coefficients of variation (CV) of particle sizes ranked as clay> silt> sand while soil pH ranged between 5.2 and 5.75, and organic matter ranged from 7.4 in Ntamkpo to 20.3 gkg-1 in Idomi with CV of 27.54%. Total N was generally low in the soils with CV of 31.25% in the surface soils and 58.36% in the subsurface soils. Available P and exchangeable basic cations were rated low but with high CVs except for exchangeable K+ and Na+ and ranked as P> Mg> Ca> Na> K. The ECEC was however rated medium with CV of 23.8% in the surface soils. It was however observed, that ECEC and organic matter were among the most spatially variable properties in the area. Intensified soil tests and farmer education were suggested to control the use of agrochemicals while unhealthy practices such as bush burning and unplanned continuous cropping should be checked. The integrated use of calcitic and dolomitic limes with organic inputs, crop rotation and bush fallow systems were also advocated.
The soils of some selected areas in Benue state were characterized and classified in 2009 for the purpose of providing information necessary for good land use planning for sustainable Agriculture. Six profile pits were sunk and soil samples were collected for physical and chemical laboratory analysis. The textural composition of the soil ranged from loamy sand to sandy loam to clay loam. The pH ranged from slightly to moderately acidic in reaction in most parts of the areas. The organic matter was very low in all the study areas. Available phosphorus was low in all the locations. Total Nitrogen was predominantly very low to low. CEC also ranged from very low to low. The soils were classified as follows: SIWES Farm Typic ustochrepts, Obarike Oju, Vertic tropaquept and Otobi Typic Kandiaqualf. NYSC farm, Typic Kandiustalf; Adum-Ito, Typic Kandiustalf; and Otukpa, Oxic Ustropept. The soils of the study areas follow the class II of the land capability classification that is the soils are classified as moderate to good land with few physical and chemical limitations which can be improved to enhance crop production within study areas.
The study of transformations that occur in the soil, resulting from the use and management adopted, is very important in the choice of the most suitable system to recover the soil functions. Thus, the aim of this study was to assess the impact of agroforestry systems (AFS´s) management, in different successional stages, on soil physical quality in south of São Paulo state (Brazil). The work was conducted under an Ultisol (Arenic Dystrudult). It was evaluated the fowling physical soil attributes: density, porosity, flocculation index and soil aggregate stability. The experiment was conducted in factorial scheme, and graded on type of use/management (AFS 12 years; AFS 2.5 years; AFS 1 year and native forest) as well as depth (0-0.10; 0.10-0.20; 0.20-0.40 m). The results showed that over time, consolidated agroforestry systems provide less impactful alternatives and can assist in reversing the degradation processes, increasing soil porosity under these systems and reduce soil density, greater stability of aggregates and smaller thermal variations of soil. Therefore, consolidated agroforestry systems (12 years) promote a resilience of the soil structure and should be included in the production system, especially in regions of environmental preservation.
The influence of low-dose gamma rays (80 Gy) on the morphometric properties of bread wheat at the stage of seed germination under salt stress was studied and the changes in the water regime, the amounts of photosynthetic pigments and the activity of PSII 14- and 21-day leaves were determined. Seeds of the bread wheat varieties Mirbashir-1 and Sheki-1 were used as the objects of the study. Seeds were exposed to gamma rays (80 Gy) emitted by Co60 isotope. The seeds exposed to gamma rays were germinated using the roll method for studying the effect of salt on morphophysiological indices of wheat seedlings. For this purpose seeds of each sample were maintained on wet filter paper at 20-22°C constant temperature, in darkness for 3 days and then moved to a photoperiod of 12 hours dark/12 hours light and germinated for 11 days. Different concentrations of NaCl (0, 150, 200 mmol.L-1) were used in the experiments. The research revealed that gamma rays with a dose of 80 Gy partly eliminate the negative effect of salt stress on germination capacity, growth of shoots and roots, RWC of leaves, amounts of photosynthetic pigments and the activity of PS II.
Effect of different planting depths on germination and the emergence of different local rice cultivars; Mai manja, B.G Doguwa and Nerica as control, were investigated under different planting depth conditions of 2 cm, 4 cm and 6 cm depths respectively. There were three (3) replicates each of the rice cultivars sowed in transparent potting polythene bags under the three (3) different seeding depths. Germination rate was determined by measuring the shoot length (cm) that firstly emerged faster, twice weekly for six weeks. After harvest, root length (cm), biomass (g) and root to shoot ratios of the rice cultivars were measured. Results showed that the local rice varieties seeds can emerge from deep down 6 cm depth. The seedlings of the local variety, BG Doguwa were noticed to be significantly taller at (P<0.005) when the seeds were sown on the soil surface in well-aerated soils with no standing water at 2-cm depth by producing increased heights of 97.70 cm compared to Mai manja and Nerica which were having shoot length of 80.40 cm and 79.40 cm respectively. The three cultivars showed significant differences (P<0.001) of emergence and germination characteristics under the 3 (three) different planting depths where both the tested cultivars including the control variety (Nerica) emerge faster in the 2-cm planting depth. It is suggested that further research should be carried out to determine suitable planting depths for various rice varieties as well as to improve on the varieties with higher germination and faster seedling emergence which can produce more vigorous seedling yield under different seeding depths.