2,737 research outputs found

    ECONOMIC EFFECT OF IMPERFECT INFORMATION ON CONSERVATION DECISIONS

    Get PDF
    Cotton farmers in the Piedmont region incorrectly believe conservation systems with winter cover crop and no-till cultivation yield less than conventional systems. We model the effect of organic matter on productivity and show how ignoring this effect causes returns to be underestimated. Farmers with imperfect information underinvest in residue management.residue management, organic matter, productivity, comparative statics, Farm Management, Land Economics/Use, Productivity Analysis,

    MEETING THE KYOTO TARGET THROUGH CONSERVATION TILLAGE AND ITS IMPLICATION FOR NATURAL CAPITAL MAINTENANCE, PRODUCTION EFFICIENCY, AND SUSTAINABILITY

    Get PDF
    According to Article 3.4 of the Kyoto Protocol, agricultural soil could be used as a sink for carbon sequestration and hence it may provide an alternative venue to sequester the greenhouse gas emission. US plans to reduce the carbon emission amount by seven percent below the 1990 level within the target date of 2008-2012. The major approaches to achieve the goal targeted by Kyoto Protocol in US are through fossil fuel tax and increasing forest area by afforestation. This means fossil fuel price will increase which will have a direct impact to conventional tillage cost. As a result farmers would be motivated to use less machinery operation in farming and hence may use conservation tillage in farming practices. Rather than cause and effect relationship created by fuel price increase, conservation tillage itself has been considered as a method suggested to increase carbon sequestration. We analyze the economic and environmental roles of conservation tillage in carbon sequestration. The use of conservation tillage helps to sequester carbon in the form of soil organic matter. We examined the potential of conservation tillage in sequestering carbon and its role in increasing soil natural capital and thus the productivity of soil. We then used the concept of production efficiency to calculate the benefits of soil carbon sequestration using sustainability criteria. The detail of carbon sequestration and soil natural capital buildup were demonstrated using conservation tillage practiced in cotton production in Georgia. Four systems of conservation tillage encompassing both chemical and organic source of plant nutrients were compared for their capacity to sequester carbon. Organic matter buildups were faster in a system with conservation tillage and organic sources of nutrient compared to conventional tillage. Result indicated that in a system with a slow buildup of natural capital, production efficiency was not significant. This has resulted the system to be unprofitable in the short run and unsustainable in the long run. The system with a high amount of organic matter increases the production efficiency of applied inputs and also plays an important role in substituting chemical fertilizers. Alternative tillage management systems were evaluated for their sustainability using total factor productivity. It was found that conservation tillage meets criteria of sustainability more often than the management system containing conventional tillage. Conservation tillage was found to be the best alternative not only to sequester carbon but also developing natural capital-based sustainable system.Kyoto protocol, Carbon sequestration, Natural capital, Production efficiency, Sustainability, Environmental Economics and Policy, Productivity Analysis,

    DYNAMIC ECONOMIC ANALYSIS OF A RESIDUE MANAGEMENT SYSTEM IN COTTON

    Get PDF
    Residue management system (RMS), comprised of no till cultivation, a winter cover crop, and poultry litter, could be an alternative to existing management system in cotton production in the Georgian Piedmont. We compare the productivity and profitability of RMS with the current system over time, focusing on the role of organic matter. Using dynamic bioeconomic modelling technique, we show that the net return and land value difference between these two systems increase as the terminal period increases. We conclude that if financial and capital markets based on organic matter work efficiently, farmers will choose RMS in cotton production.residue management, organic matter, productivity, Crop Production/Industries,

    DYNAMIC ANALYSIS OF A RESIDUE MANAGEMENT SYSTEM IN COTTON

    Get PDF
    Residue management system (RMS) offers increase productivity gain to farmers by increasing the organic matter. Farmers have failed to realize this gain and consequently have not adopted RMS in cotton cultivation. Benefit of adopting RMS system appears sooner than farmers would think.Environmental Economics and Policy, Productivity Analysis,

    FROM THE PERSPECTIVE OF GLOBAL WARMING: ALTERNATIVE FARMING SYSTEMS AND SUSTAINABILITY

    Get PDF
    According to Article 3.4 of the Kyoto Protocol, agricultural soil could be used as a sink for carbon sequestration. Soil sequestration of carbon provides dual benefits: an increase in soil productivity and a reduction in atmospheric carbon concentration. The gain in soil productivity is a slow process and attaining a steady-state level of carbon in soil takes several years. A frequently encountered difficulty in this situation is how to discount the future benefit of carbon sequestration into a current term. We compared the net benefit of four alternative management systems using discount rates based on the sliding gamma distribution, market rate of investment, and the social rate of time preference. We also calculated the sustainability of these alternate management systems based on the profitability and productivity index and their capacity to maintain the natural capital in soil. The result indicated that a management system that combines no-till and an organic source of nutrients is the most attractive system based on carbon sequestration, total discounted net present value, and sustainability perspectives.carbon sequestration, conservation practices, strong and weak sustainability, discounting method, Environmental Economics and Policy, Production Economics,

    EFFECT OF RISK PERSPECTIVE ON FERTILIZER CHOICE BY SHARECROPPERS

    Get PDF
    Peanut and corn are two major crops in the tri-state area of the Southeast US, an area encompassing North Florida, Southwest Georgia, and Southeast Alabama. Sharecroppers in this region apply higher amount of input in crop production than the average farmers. We analyzed the behavior of sharecroppers in this region with regard to their fertilizer application decisions. Two hypotheses were formulated and tested based on sharecroppers' fertilizer application decisions: one assuming that sharecroppers are risk averse farmers and the other assuming that sharecroppers are regret minimizers. Our results show that a sharecropper uses different fertilizer treatments when minimizing risk depending on risk perspective and desired income. Sharecroppers who apply more fertilizer to obtain a desired level of income are regret minimizers where as sharecroppers who apply relatively low fertilizer are risk minimizer. At the same desired level of income, a regret minimizer farmer would apply a higher amount of fertilizer than the risk averse farmers. Our analysis revealed that sharecroppers in the Southeast US are regret minimizers as they apply a higher amount of fertilizer than an average farmer on the major crops grown in the region. The result of this study also confirms the result of a previous study in the region which reported that sharecroppers in the region are over capitalized and apply more fertilizer than average farmers.Southeast U.S., Sharecroppers, Regret minimizer, Risk averse, Peanut-Corn rotation, Farm Management, Risk and Uncertainty,

    New Cepheid variables in the young open clusters Berkeley 51 and Berkeley 55

    Get PDF
    As part of a wider investigation of evolved massive stars in Galactic open clusters, we have spectroscopically identified three candidate classical Cepheids in the little-studied clusters Berkeley 51, Berkeley 55 and NGC 6603. Using new multi-epoch photometry, we confirm that Be 51 #162 and Be 55 #107 are bona fide Cepheids, with pulsation periods of 9.83±0.01 d and 5.850±0.005 d respectively, while NGC 6603 star W2249 does not show significant photometric variability. Using the period-luminosity relationship for Cepheid variables, we determine a distance to Be 51 of 5.3 +1.0 −0.8 kpc and an age of 44 +9 −8 Myr, placing it in a sparsely-attested region of the Perseus arm. For Be 55, we find a distance of 2.2±0.3 kpc and age of 63 +12 −11 Myr, locating the cluster in the Local arm. Taken together with our recent discovery of a long-period Cepheid in the starburst cluster VdBH222, these represent an important increase in the number of young, massive Cepheids known in Galactic open clusters. We also consider new Gaia (data release 2) parallaxes and proper motions for members of Be 51 and Be 55; the uncertainties on the parallaxes do not allow us to refine our distance estimates to these clusters, but the well-constrained proper motion measurements furnish further confirmation of cluster membership. However, future final Gaia parallaxes for such objects should provide valuable independent distance measurements, improving the calibration of the period-luminosity relationship, with implications for the distance ladder out to cosmological scales

    The Arches cluster revisited: II. A massive eclipsing spectroscopic binary in the Arches cluster

    Get PDF
    We have carried out a spectroscopic variability survey of some of the most massive stars in the Arches cluster, using K-band observations obtained with SINFONI on the VLT. One target, F2, exhibits substantial changes in radial velocity; in combination with new KMOS and archival SINFONI spectra, its primary component is found to undergo radial velocity variation with a period of 10.483+/-0.002 d and an amplitude of ~350 km/s-1. A secondary radial velocity curve is also marginally detectable. We reanalyse archival NAOS-CONICA photometric survey data in combination with our radial velocity results to confirm this object as an eclipsing SB2 system, and the first binary identified in the Arches. We model it as consisting of an 82+/-12 M⊙ WN8-9h primary and a 60+/-8 M⊙ O5-6 Ia+ secondary, and as having a slightly eccentric orbit, implying an evolutionary stage prior to strong binary interaction. As one of four X-ray bright Arches sources previously proposed as colliding-wind massive binaries, it may be only the first of several binaries to be discovered in this cluster, presenting potential challenges to recent models for the Arches' age and composition. It also appears to be one of the most massive binaries detected to date; the primary's calculated initial mass of >~120 M⊙ would arguably make this the most massive binary known in the Galaxy

    Orbital period changes and the higher-order multiplicity fraction amongst SuperWASP eclipsing binaries

    Get PDF
    Orbital period changes of binary stars may be caused by the presence of a third massive body in the system. Here we have searched the archive of the Wide Angle Search for Planets (SuperWASP) project for evidence of period variations in 13 927 eclipsing binary candidates. Sinusoidal period changes, strongly suggestive of third bodies, were detected in 2% of cases; however, linear period changes were observed in a further 22% of systems. We argue on distributional grounds that the majority of these apparently linear changes are likely to reflect longer-term sinusoidal period variations caused by third bodies, and thus estimate a higher-order multiplicity fraction of 24% for SuperWASP binaries, in good agreement with other recent figures for the fraction of triple systems amongst binary stars in general

    Intrinsically Bent DNA in the Promoter Regions of the Yeast GAL1–10 and GAL80 Genes

    Full text link
    Circular permutation analysis has detected fairly strong sites of intrinsic DNA bending on the promoter regions of the yeast GAL1–10 and GAL80 genes. These bends lie in functionally suggestive locations. On the promoter of the GAL1–10 structural genes, strong bends bracket nucleosome B, which lies between the UASG and the GAL1 TATA. These intrinsic bends could help position nucleosome B. Nucleosome B plus two other promoter nucleosomes protect the TATA and start site elements in the inactive state of expression but are completely disrupted (removed) when GAL1–10 expression is induced. The strongest intrinsic bend (;70°) lies at the downstream edge of nucleosome B; this places it approximately 30 base pairs upstream of the GAL1 TATA, a position that could allow it to be involved in GAL1 activation in several ways, including the recruitment of a yeast HMG protein that is required for the normally robust level of GAL1 expression in the induced state (Paull, T., Carey, M., and Johnson, R. (1996) Genes Dev. 10, 2769–2781). On the regulatory gene GAL80, the single bend lies in the non-nucleosomal hypersensitive region, between a GAL80-specific far upstream promoter element and the more gene-proximal promoter elements. GAL80 promoter region nucleosomes contain no intrinsically bent DNA
    corecore