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Alves, P. N., Melo, I. C., Santos, R. D., da Rocha, F. V., & Caixeta, J. V. (2022). How did COVID-19 affect green-fuel supply chain? – A performance analysis of Brazilian ethanol sector. Res. Transp. Econ., 93, 101137.
Abstract: The COVID-19 pandemic affected many supply chains worldwide, including the Brazilian green-fuel ethanol supply chain. Our analysis considered sustainability variables (social, environmental, and economic) to investigate the pandemic's effects on the ethanol industries of 15 ethanol producing Brazilian states, comparing data from 2020 to 2019 and applying a novel Data Envelopment Analysis (DEA): the Double Frontier Slack-Based Measure Malmquist Productivity Index (DF-SBM MPI). The findings show that all states suffered negative impacts from the pandemic and some incurred a risk of collapsing it. The least negatively impacted states were Sao Paulo and Mato Grosso. Sao Paulo's ethanol sector is a benchmark for income derived from trade in carbon-credits by RenovaBio certified mills, while Mato Grosso's sector is able to take advantage of the largest spread between ethanol and gasoline prices, certainly a competitive advantage for ethanol producers. We recommend the implementation of public policies to support, mainly, the most affected states by assisting their mills to become environmentally certified participants to take advantage of income opportunities available in the carbon-credit trading market. We recommend, among other actions, a temporary ethanol sales tax reduction, an extension of debt repayment schedules, and stimulating an increase in the fleet of flex-fuel vehicles.
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Beya-Marshall, V., Arcos, E., Seguel, O., Galleguillos, M., & Kremer, C. (2022). Optimal irrigation management for avocado (cv. 'Hass') trees by monitoring soil water content and plant water status. Agric. Water Manag., 271, 107794.
Abstract: Irrigation scheduling based on soil water content (Ow) sensors requires that Ow be maintained within a range (management lines) that is optimal for plant growth. The lower limit or “breaking point ” is determined following the soil water content dynamics on the transition of a rapid rate of depletion to a slower, under similar reference evapotranspiration. Although this criterion is practical, its implementation should be validated with plant water status measurement that contemplate weather condition, such as stem water potential “non-stressed ” baseline (Tx as a function of vapor-pressure deficit (VPD) in Ow conditions that do not limit yield). A study was con-ducted on a mature cv. 'Hass' avocado orchard in Central Chile during two seasons. There were 5 irrigation treatments: T1, Control; T2 and T3 with 29% less and 25% more of what was applied in T1, respectively; T4 and T5 same as Control until first and second fruit drop abscission, respectively, and then with 29% less. T1 trees were irrigated using a continuous frequency domain reflectometry (FDR) probe to maintain the root zone be-tween field capacity and the breaking point. There was biweekly monitoring of the Ow prior to irrigation, Tx and VPD. The Tx decline proportional to the intensity and the timing of water restriction; however, no treatment affected the crop load in either season. T2 did not show significant detrimental in fruit size, production and maturation, despite that frequently reached water content levels at the limit of the breaking point, and showed lower levels of stem water potential than Control, being the treatment with the highest water productivity. The results confirm that breaking point is an effective criterion to establish irrigation management. Additionally, when comparing the baseline for our non-stressed trees with a baseline from full irrigation treatments obtained from the literature, 30% water savings were achieved.
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Yushimito, W. F., Holguin-Veras, J., & Gellona, T. (2018). Firm's efficiency and the feasibility of incentives for flextime adoption: a preliminary analysis of Chilean employer's response. Transp. Lett., 10(4), 202–214.
Abstract: Flextime is a Travel Demand Management policy that allows workers to arrive/leave within a certain threshold of time but staying on duty during a period of the day (core hours). Such flexibility in arrival time can have an impact on relieving traffic congestion as it can shift demand to nonpeak periods. However, in several countries, companies are usually reluctant to provide flexibility arguing possible loss in their productivity and efficiency. This paper discusses a preliminary study on perceptions of challenges, and the potential of flextime in congested urban areas. In doing so, we present the information gathered through in-depth-interviews and subsequent questionnaires applied to managers of cars dealers in Santiago, Chile, obtaining both qualitative and quantitative information. The quantitative information obtained was used to develop (1) a data envelopment analysis to investigate whether firms' productivity is affected by flextime or not, and (2) a binary logit model to evaluate financial and non-financial incentives that can allow firms to adopt flextime or change work arrival times. The results obtained from the sample show that, for this particular industry, flextime might not have a significant impact on firms' productivity. Additionally, we found that financial incentives and competitors' work starting times have a significant impact on accepting flextime or relaxing arrival constraints. We also found that if arrangements with the whole industry to change work starting times are made, the effect of this change can be as effective as the provision of financial incentives.
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