Increasing input self-sufficiency is often viewed as a target to improve sustainability of dairy farms. However, few studies have specifically analysed input self-sufficiency, by including several technical inputs and without only focussing on animal feeding, in order to explore its impact on farm sustainability. To address this gap, our work has three objectives as follows: (1) identifying the...

abstract comparative advantage is an economic term which is used to compare potential and actual production capacity of a country in a given commodity with the rest of the world. therefore, researches in this field could have a dual approach. in one hand it could demonstrate country’s production capacity in the production of commodities that are not produced yet and in the other hand it can ill...

The spiraling concept provides an explicit approach to modeling the longitudinal linkages within a river continuum. I developed a spiraling-based model for particulate organic C dynamics in the Little Tennessee River to synthesize existing data and to illustrate our current understanding of ecosystem processes in river ecosystems. The Little Tennessee River is a medium-sized river flowing ;100 ...

Terrestrial organic matter can be assimilated by aquatic consumers but implications for biomass and production are unresolved. An ecosystem model was fit to estimate effects of phosphorus (P) load, planktivory, and supply rate of terrestrial particulate organic carbon (TPOC) on phytoplankton and zooplankton in five whole-lake experiments. Phytoplankton biomass increased with P load and planktiv...

awardness about structure of production technology and its characteristics is a usefull tool for planning in agricultural sector. in this regard, this study aims to determine some effective parameters of structure of production technology in rain fed barley production. before estimating these parameters, we examine the aggregation consistency condition for barley fields using the mean scaling t...

Due to their spatial complexity and dynamic nature, floodplains provide a wide range of ecosystem functions. However, because of flow regulation, many riverine floodplains have lost their characteristic heterogeneity. Restoration of floodplain habitats and the rehabilitation of key ecosystem functions, many of them linked to organic carbon (C) dynamics in riparian soils, has therefore become a ...

regard to increasing demand for organic agricultural products, awareness of costs and profitability of organic products can help to decision planners of agricultural sector, and particularly farmers. this study has tried to calculate cost and profitability of cotton product in two different conventional and organic ways (procedure) of production using 253 cross-sectional data from khorasan raza...

We investigated bacterial responses to variations in dissolved organic carbon (DOC) and nutrient availability by a comparative analysis of bacterial metabolism in lakes ranging from oligotrophic to eutrophic. Bacterial growth, respiration, and growth efficiency were quantified in lake water dilution cultures performed in 20 lakes located in eastern Quebec, Canada, which varied with respect to b...

Seasonal and spatial distributions of extracellular enzymatic activities and microbial incorporations of dissolved organic substrates were followed in sediments of the brackish water Kiel Bight (Baltic Sea, Federal Republic of Germany). Enzymatic hydrolysis of polymeric organic compounds was determined by means of fluorogenic substrates (4-methylumbelliferyl-beta-d-glucoside, l-leucine-4-methyl...