EURASIAN JOURNAL OF SOIL SCIENCE

103-108

Authors: Ram Asheshwar Mandal, Ishwar Chandra Dutta, Pramod Kumar Jha

This research was objectively carried out to assess the dynamic of carbon, nitrogen and texture at root zone and location between plants. The plantation of Acacia catechu, Dalbergia sissoo, Phyllanthus emblica and Eucalyptus camaldulensis of Pragati community forest, Mahottari district, Nepal was selected for this study which was done in 2011. The stratified random sampling was applied to collect soil samples. Altogether 320 soil samples were collected from 0-10, 10-30, 30-60 and 60-90 cm depths. The result showed that soil carbon was about 8.16 t ha-1 at root zone which was only 7.56 t ha-1 at location between plants at 0-10cm depth in Phyllanthus emblica stratum. The soil carbon was the least nearly 2.08 t ha-1 at root zone which was 1.59 t ha-1 at location between plants in Eucalyptus camaldulensis stratum. The carbon percentage was the highest about 1.35% at root zone of Phyllanthus emblica stratum. However, the C/N ratio was the highest about 69:1 at location between plants of Dalbergia sissoo stratum. The texture of soil was loamy sand at root zone in Phyllanthus emblica, Acacia catechu and Dalbergia sissoo plantations while it was sandy at both root zone and between plants of Eucalyptus plantation. Plantations have significant effect on soil carbon and nitrogen at 95% confidence level.

115-120

Authors: Siyami Karaca, Füsun Gülser, Ramazan Selçuk

The objective of this study was to determine the relationship between soil properties and different topography and land uses in the Van Lake Basin, Turkey. It has sharp and sheer slopes, and the big differences on altitude generally occur from the mountainous formations. Surface soil samples (0–20 cm) were taken from 40 different points with three different topography (backslope, footslope and terrace) and three different landuses (wheat, clover and pasture). Some of the studied soil properties (soil texture, electrical conductivity [EC], pH, lime content, organic matter content, macro and micro nutrients) changed in response to land use and topography. The clay, boron content, pH and EC values increased from the backslope to the terrace. Soil organic matter and EC values were lower in cultivated wheat and clover fields than in uncultivated pasture. The EC values had significant positive correlations with CaCO3, organic matter, K, B, Cu contents at 5% level and with Mg at 1% level statistically. The soil nutrient contents of cultivated wheat and clover fields were generally lower than the uncultivated pasture. The nutrient contents of soils in cultivated fields decreased due to nutrient uptake by crops. Soil texture, EC, pH, lime, organic matter and nutrient contents significantly varied in different topographic positions due to leaching, transporting and accumulation.

133-150

Authors: Idowu Ezekiel Olorunfemi, Johnson Toyin Fasinmirin, Funke Florence Akinola

Proper utilization of land is essential to soil quality maintenance and sustainable agricultural development. This study was conducted to evaluate effects of land use management on physico-chemical characteristics of soils in Ekiti State, Southwestern Nigeria. In this study, a total of 105 sampling points in 35 locations comprising of the 3 land uses were sampled. Random sampling pattern of 3 sampling points per location were carried out and undisturbed soil samples were collected at depths up to 30 cm. Soil physical properties (bulk density (BD), water holding capacity (WHC), and particle size distribution) and chemical properties (organic matter content (SOM), cation exchange capacity (CEC), phosphorus (P) and organic nitrogen (SON)), were determined and evaluated. Results showed that natural forest on the overall accumulated more nutrients than plantations and cropland. The highest SOM value of 4.07 % was recorded in the natural forests, while the lowest value of 1.52 % was found in the croplands. Organic matter accumulation showed a decreasing trend in the order: forest > plantation > cropland. Natural forest soils had significantly higher volumetric moisture content (VMC) than plantations and croplands. Correlation analysis of the 11 physico-chemical properties for the study area, showed a significant correlation among 70 of the 190 soil attribute pairs. Land use system reveals a significant decline of soil quality under cropland. Management systems by which soil could be improved towards the development of suitable agricultural management systems must be incorporated during land cultivation. In order to have sustainable land use systems, land use development must not be only economically sustainable but also socially acceptable and environmentally sound. Therefore, strategies to improve agricultural productivity have to seek a sustainable solution that better addresses soil fertility management.

167-180

Authors: Hamidreza Owliaie, Mahdi Najafi Ghiri, Sirous Shakeri

Soils of semiarid regions of Dehdasht and Choram in Southwestern Iran have formed on alluvium derived from mixed calcareous-gypsiferous materials from Lower Miocene to Upper Pliocene. In order to characterize and classify the soils and to determine the soil-landscape relationship in the area, nine pedons located on different physiographic positions including plateau, river alluvial plain, piedmont plain, alluvial plain and alluvial fan have been described, sampled and analyzed. Physicochemical analyses, clay mineralogy and micromorphological studies were performed. The results showed that topography and parent material were two important soil forming factors affecting soil formation in the area. The soils were dominated by carbonate, gypsum, and clay illuviation and accumulation. More developed soils were found on the stable plateau and piedmont plain. Clay illuviation and argillic horizon development in soils of the more stable alluvial plain were assumed to be relict features from presumably more humid climates. Palygorskite, illite, chlorite, smectite, kaolinite, and quartz clay minerals were identified in almost all physiographic surfaces, but more palygorskite and less smectite were found in the soils with gypsiferous parent materials. Observations by SEM revealed the occurrence of neoformed palygorskite as thread-like faces and coating of gypsum crystals and marly matrix. Coating and infilling of gypsum and calcite crystals in voids and channels were common pedofeatures observed in the soils studied. Two different distribution patterns of Fe-Mn oxides were identified in aquic and non-aquic soils.

187-194

Authors: Abigail O. Ojo, Michael T. Adetunji, Christopher O. Adejuyigbe, Ibukun O. Fademi

Phosphorus inputs to the soil are primarily from the application of fertilizer P and organic resources. A ten week incubation study was carried out to determine the effects of organic and inorganic P sources on phosphorus fractions in three derived savanna soils. Poultry manure was applied at 0, 0.75g, 1.5g, 2.25g and 3g per 300g weight of soil while single superphosphate was applied at 0.0023g, 0.0046g, 0.0069g and 0.0092g per 300g of soil. Sampling was done at two weeks interval. At 0 week of the incubation study, Ekiti series had the largest amount of P fractions i.e. Fe-P, Al-P, residual P, reductant soluble P, occluded P, organic P and occluded P while Ca-P was high in Apomu series. However, increases in Fe-P, Al-P, Ca-P and organic P were observed in the three soil series evaluated and poultry manure was notably effective in reducing P occlusion. In conclusion, it was observed that irrespective of the soil series at different stages of the incubation studies, poultry manure and the combined application of poultry manure and Single superphosphate was highly effective in increasing P fractions.