Organizational aspects of improved irrigation management: An experiment in Dewahuwa Tank, Sri Lanka

Irrigation management / Organizations / Tank irrigation / Farmer-agency interactions / Water allocation / Rotation / Diversification / Crops / Sri Lanka / Dewahuwa

Perturbations in growth trajectory due to early diet affect age-related deterioration in performance

Fluctuations in early developmental conditions can cause changes in growth trajectories that subsequently affect the adult phenotype. Here, we investigated whether compensatory growth has long-term consequences for patterns of senescence. Using three-spined sticklebacks (Gasterosteus aculeatus), we show that a brief period of dietary manipulation in early life affected skeletal growth rate not only during the manipulation itself, but also during a subsequent compensatory phase when fish caught up in size with controls. However, this growth acceleration influenced swimming endurance and its decline over the course of the breeding season, with a faster decline in fish that had undergone faster growth compensation. Similarly, accelerated growth led to a more pronounced reduction in the breeding period (as indicated by the duration of sexual ornamentation) over the following two breeding seasons, suggesting faster reproductive senescence. Parallel experiments showed a heightened effect of accelerated growth on these age-related declines in performance if the fish were under greater time stress to complete their compensation prior to the breeding season. Compensatory growth led to a reduction in median life span of 12% compared to steadily growing controls. While life span was independent of the eventual adult size attained, it was negatively correlated with the age-related decline in swimming endurance and sexual ornamentation. These results, complementary to those found when growth trajectories were altered by temperature rather than dietary manipulations, show that the costs of accelerated growth can last well beyond the time over which growth rates differ and are affected by the time available until an approaching life-history event such as reproduction

Non-centralized Control for Flow-based Distribution Networks: A Game-theoretical Insight

This paper solves a data-driven control problem for a flow-based distribution network with two objectives: a resource allocation and a fair distribution of costs. These objectives represent both cooperation and competition directions. It is proposed a solution that combines either a centralized or distributed cooperative game approach using the Shapley value to determine a proper partitioning of the system and a fair communication cost distribution. On the other hand, a decentralized noncooperative game approach computing the Nash equilibrium is used to achieve the control objective of the resource allocation under a non-complete information topology. Furthermore, an invariant-set property is presented and the closed-loop system stability is analyzed for the non cooperative game approach. Another contribution regarding the cooperative game approach is an alternative way to compute the Shapley value for the proposed specific characteristic function. Unlike the classical cooperative-games approach, which has a limited application due to the combinatorial explosion issues, the alternative method allows calculating the Shapley value in polynomial time and hence can be applied to large-scale problems.Generalitat de Catalunya FI 2014Ministerio de Ciencia y Educación DPI2016-76493-C3-3-RMinisterio de Ciencia y Educación DPI2008-05818Proyecto europeo FP7-ICT DYMASO

The impact of concentrated pig production in Flanders : a spatial analysis

Historically concentrated livestock production and, consequently, manure production and management in Belgium have resulted in severe environmental impacts. One major impact, nitrate leaching from soil to surface water, is being tackled through the European Nitrates Directive by imposing strict fertilization standards. However, another significant impact of manure management is the emission of greenhouse gasses (GHG - CO2, CH4, NH3 and N2O) into the air, thereby contributing to global warming. Calls have been made to reduce the high manure pressure and related environmental effects in Belgium by relocating and more evenly spreading livestock production. This paper explores the spatial spreading of CO2-equivalent emissions from livestock production in Belgium and attempt to answer the following question: ‘Can spatial reallocation of livestock production in Belgium reduce the impact of GHG emissions?’. This question is translated into several research objectives: 1) conduct an economic (cost minimization) and environmental (GHG minimization) optimization for 3 manure management scenarios, 2) determine the main differences between both approaches, and 3) determine the marginal spatial impact on CO2 emissions of a decrease in manure pressure (i.e., increased spreading of pig production). To conduct the analysis, a model was developed that builds on the spatial mathematical programming multi-agent manure allocation model developed by Van der Straeten et al. (2010). Three options for manure management are inserted: transport of raw manure from nutrient excess to nutrient deficit areas, biological treatment of manure (manure processing) and manure separation. The model optimizes, at municipal level, either the cost-efficiency, either the environmental effect of the manure market in Belgium based on Belgian fertilization standards. While cost-efficiency is calculated based on transport distances and cost of manure separation and processing, GHG emissions, and hence, carbon footprint, are determined based on a life cycle analysis type calculation. The results of the model simulations show that, while the economic optimum is reached by maximizing the transport of raw manure until fertilization standards are fulfilled and subsequently separating and processing the excess manure, the environmental optimum, from a carbon footprint point of view, is reached by separating all manure as this option has the lowest CO2 emissions, mainly due to the limited manure storage time. Moreover, the analyses indicate that rearrangement of the spatial spreading of livestock production in Belgium will not substantially decrease CO2 emissions. As manure storage is the main contributor to the carbon footprint, solutions should rather lie in changing these storage systems

Water Allocation Mechanisms: Principles and Examples

From the earliest times, water resources have been allocated on the basis of social criteria - maintaining the community by ensuring that water is available for human consumption, for sanitation, and for food production. Societies have invested capital in infrastructure to maintain this allocation. Yet social change, including changes in (and more understanding of) how goods are distributed, has produced new issues in water allocation. Population growth has made water scarcity a major problem in many countries and water pollution, while by no means a recent problem, is more widespread than ever before. Traditionally the state has played a dominant role in managing water resources, but inefficient use of water, poor cost recovery for operating and maintenance expenses, the mounting cost of developing new water sources, and problems with the quality of service in agency-managed systems has led to a search for alternatives that make water allocation and management more efficient. The authors address some of the basic principles of treating water as an economic good and of allocating it among the sectors. After outlining the economic principles behind allocating scarce water resources, they review the actual means of various mechanisms used for allocating water, including marginal cost pricing, social planning, user-based allocation, and water markets. Giving examples from experience in several countries, they weigh the pros and cons of different approaches to water allocation, showing that no single approach is suitable for all situations. Clearly that state must play an important regulatory role, for example, but how effectively it does so depends on the relative political influence of various stakeholders and segments of society. User-based allocation is generally more flexible than state allocation, but collective action is not equally effective everywhere; it is most likely to emerge where there is strong demand for water and a history of cooperation. The outcome of market allocation depends on the economic value of water for various uses, but moving toward tradable property rights in water may ease the process of intersectoral reallocation by compensating the"losers"and creating incentives for efficient water use in all sectors

Federal Road Charge Tax Administration Process

The gasoline tax is one of the primary sources of revenue for transportation infrastructure funding. However, recent revenue shortfalls due to a combination of inflation, fuel efficiency improvements, and vehicle electrification have led to discussions of alternative funding mechanisms such as the road user charge where drivers would pay fees by miles driven rather than gallons consumed. In this report, researchers investigate the institutional structure of the current gasoline tax at the federal level including historical changes, how the tax is collected, and how it is allocated and disbursed to fund infrastructure projects. In outlining the structure of the current gasoline tax, they identify key opportunities for a road user charge to be integrated into the current funding system. These include considerations for tax evasion, simplification of state level allocated disbursement formulas, re-allocation of funds, and designating spending for fuel-specific infrastructure.View the NCST Project Webpag

Multiple uses of water in irrigated areas: a case study from Sri Lanka

Water management / Water allocation / Water use efficiency / Irrigated farming / Water resources development / Water policy / Water quality / Domestic water / Water users' associations / Water rights / Gender / Households / Pricing / Water costs / Case studies / Sri Lanka / Kirindi Oya

Desirable Host Plant Qualities in Wild Rice \u3ci\u3e(Zizania Palustris)\u3c/i\u3e for Infestation by the Rice Worm \u3ci\u3eApamea Apamiformis\u3c/i\u3e (Lepidoptera: Noctuidae)

The rate at which an insect infests hosts by ovipositioning and/or subsequent growth of larvae often depends on specific desirable host plant qualities. In this study, we measured the infestation rate of wild rice, Zizania palustris, by the wild rice worm, Apamea apamiformis, D. F. Hardwick (Lepidoptera: Noctuidae) and compared it to sediment nitrogen availability, plant biomass, plant density, litter accumulation, and seed carbohydrate and nitrogen concentration. Plant density and litter accumulation had no effect on infestation rates. Infestation rate increased with plant biomass and sediment nitrogen availability. The correlation between infestation rate and sediment nitrogen availability seems to reflect the fact that high nitrogen availability produces larger plants rather than more nutritious seeds as the infestation rate was not correlated with seed glucose content and surprisingly decreased with concentration of nitrogen in seeds. Infestation rate was not related to any other measured quantities. Therefore, Apamea appear to infest larger, rapidly growing host plants which are made possible by high sediment nitrogen availability