SUMMARY:The main objective of this paper was to develop a separable linear programming model, considering a set of technical factors which may influence the profit of an irrigation project The model presents an objective function that maximizes the net income and specifies the range of water availability. It is assumed that yield functions in response to water application are available for differents crops and describe very well the water-yield relationships. The linear programming model was developed genetically, so that, the rational use of the available water resource could be included in an irrigation project Specific equations were developed and applied in the irrigation project "Senator Nilo Coelho" (SNCP), located in Petrolina -Brazil Based on the water-yield functions considered, cultivated land constraints, production costs and products prices, it was concluded that: (a) the model was suitable for the management of the SNCP, resulting in optimal cropping patterns and showing the water requirements; (b) for 7,424 ha of land and 66, 644,500 m 3 of water available on a year basis, the shadow price of these resources were respectively, US$ 1,115.20/ha e USS 281.60/1000 m 3 ; (c) for the total monthly water availability of 9,861,040 m 3 , the total annual water availability of 66,644,500 m 3 became an effective restriction to the increase of the net income of the production system in the SNCP; (d) maintaining the total monthly water availability of 9,861,040 m 3 , annual volumes lower than 88,338,983 m 3 were used fully to reach the optimal solution, and that higher volumes than this limit, did not increase the net return; (e) the optimization model presented, estimated a net return of 5234 % higher than the traditional cropping pattern used hi the SNCP, considering the agricultural year of 1992. , volumes anuais inferiores a 88338.983 m 3 foram utilizados plenamente pelas atividades na solução ótima e, volumes superiores a este apresentam folga, não contribuindo para o aumento da receita liquida (e) o modelo de otimização desenvolvido projetou uma receita líquida 52,34% maior que a obtida com o plano de cultivo tradicional do PSNC, considerado, como exemplo, o ano agrícola de 1992.

The present study aims to investigate the use of collaborative logistics between soybean export and fertilizer import operations in the main logistical corridors in the state of Mato Grosso to the ports of Santos and Paranaguá, aiming to identify, analyze and propose an indicator of eco-efficiency that seeks to reduce the financial and environmental impacts of this practice. For that, two scenarios were analyzed, namely: base and ideal. In the ideal scenario, the entire imported fertilizer load participates in collaborative logistics. The base scenario was defined by applying a questionnaire to 96 drivers working in the ports of Santos and Paranaguá, thus identifying the incidence of trucks that return loaded from the port areas with fertilizers. Comparing the base scenario with the ideal scenario, the potential impact regarding the costs of road transport of fertilizers is around R$ 14,696,509.89 in the port of Santos and R$ 11,806,055.10 in Paranaguá, totaling R$ 26,502,564.99. In the ideal scenario, there was a reduction in CO2 emission during 2018 in the order of 29.48 kg CO2 per ton transported in the port of Santos, with the reduction obtained in Paranaguá was 14.38 kg CO2 per ton.

The road cargo transportation system has significant representativeness in the Brazilian economic scenario. Companies depend on transportation to receive inputs from their suppliers and take their products to consumers. This modal is also the major consumer of fuel oil products in the transportation sector. Thus, it is necessary to act with a focus on sustainability, considering the economic, social and environmental aspects. From this perspective, this study aims to present aspects of the concept of sustainability in the Brazilian road freight transportation sector, with emphasis on the environmental, social and economic dimensions. A qualitative research approach was used with the literature research technique in order to build the theoretical basis for discussion on the dimensions of sustainability in Brazilian road freight transportation. The results show that the road cargo transportation sector is relevant for the country and seeks to fulfill its social role and be economically viable; requires attention to environmental awareness and eco-efficiency; should make efforts to use alternatives to avoid damage to the environment, applying technologies to reduce noise pollution, GHG emissions; and seek to comply with environmental legislation acting in a sustainable manner.

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