Quality Assessment and Suitability Evaluation of Soils under Tuber-based Cropping System in Katsina Ala Local Government Area, Benue State, Nigeria

Crop yields together with economic and social benefits of farming depend in part on land management and soil quality. Soil management and cropping systems have long-term effects on agronomic and environmental functions. This study aimed at assessing soils under yam-based cropping systems for quality and suitability so as to enhance sustainable production. The study was carried out in Katsina Ala local government area of Benue state where yam is a major crop. Sixteen modal profile were dug, described for characterization and suitability evaluation. Ten cluster locations were selected and twenty soil samples randomly collected within each cluster. The soils were subjected to laboratory analyses and results subjected descriptive statistics. Suitability of the soils for yam, citrus and groundnut were evaluated using parametric approach and soil quality of the area was assessed using Relative Soil Quality Indices (RSQI). The soils encountered are sandy to silty in nature with some having plinthite at depth. The soils, classified as Alfisol, Entisol and Inceptisol are moderately (S2) to highly suitable S1) for the three crops and have moderate to high quality for crop production with percentage soil quality index ranging from 60. 37 to 74.31 %. Soils of the study site are of good quality and are suitable for production of yam, citrus and groundnut. However, because yam is a great feeder and tropical soils are fragile making them prone to degradation, there is need for maintenance of soil fertility through organic matter management for sustainable use

Seasonal and Ontogenetic Changes in Movement Patterns of Sixgill Sharks

Understanding movement patterns is fundamental to population and conservation biology. The way an animal moves through its environment influences the dynamics of local populations and will determine how susceptible it is to natural or anthropogenic perturbations. It is of particular interest to understand the patterns of movement for species which are susceptible to human activities (e.g. fishing), or that exert a large influence on community structure, such as sharks.We monitored the patterns of movement of 34 sixgill sharks Hexanchus griseus using two large-scale acoustic arrays inside and outside Puget Sound, Washington, USA. Sixgill sharks were residents in Puget Sound for up to at least four years before making large movements out of the estuary. Within Puget Sound, sixgills inhabited sites for several weeks at a time and returned to the same sites annually. Across four years, sixgills had consistent seasonal movements in which they moved to the north from winter to spring and moved to the south from summer to fall. Just prior to leaving Puget Sound, sixgills altered their behavior and moved twice as fast among sites. Nineteen of the thirty-four sixgills were detected leaving Puget Sound for the outer coast. Three of these sharks returned to Puget Sound.For most large marine predators, we have a limited understanding of how they move through their environment, and this clouds our ability to successfully manage their populations and their communities. With detailed movement information, such as that being uncovered with acoustic monitoring, we can begin to quantify the spatial and temporal impacts of large predators within the framework of their ecosystems