Estimativa das perdas físicas e econômicas na colheita da soja em propriedades da região de Palmeira das Missões

Abstract

The objective of this research was to quantify the physical and economic losses in the pre-harvest and harvest of soybeans (Glycine max.) And the factors that may influence them. Data were analyzed according to the different models of harvesters, year of manufacture, platform size, trail systems, height of insertion of the first pod, cutting height, travel speed at harvest time, type of machine overhaul and factors linked to the operator such as age, education and participation in courses. A structured questionnaire was used to characterize the rural properties where the loss data were collected and the perception of the owners in relation to the losses in the soybean harvest and transport process. Data were collected in the months of March and April of the year 2015 and 2019, in the municipalities of Palmeira das Missões, São Pedro das Missões, Sagrada Família, Cerro Grande, Jaboticaba and Novo Tiradentes, all located in the Northwest Region of the state of Rio Grande do Sul. 215 samples were collected in the pre-harvest, 215 in the platform and 215 in the separation and cleaning trail system (STSL) in properties of 29 producers. In total, the losses of 72 self-propelled harvesters were evaluated, with a year of manufacture between 1986 and 2018. The losses were estimated using the grain weighing method and samples were collected from an area of 2m2, evaluating the losses in the pre-harvest , on the platform, STSL, on the machine and in total. Among the main results, it is noteworthy that the largest losses occurred on the platform and averaged 1.41 sc.ha-1, reflecting machine and total losses, 2.49 and 2.98 sc.ha-1, respectively . The factor year of manufacture, model (commercial brand), type of revision showed difference (P <0.05), while for the model (helical and draper) and platform size, track systems (conventional and axial), height of insertion of the first pod, cutting height, travel speed at harvest time and factors related to the operator, such as age, education, participation in courses, did not show statistical difference (P> 0.05) for harvest losses. Losses in the soybean harvest are above what is considered acceptable. The total average losses of the evaluated producers were 2.98 sc.ha-1, generating an economic loss of R $ 228.83 per ha-1. Regarding the position of the owners, the greatest losses occur due to the age of the harvester, cutting height (cm), the failure to use advanced precision technologies and the inadequate speed at harvest. Thus, considering food waste and that in developing countries, such as Brazil, this waste is greater or more concentrated in the pre-harvest and harvest the monetization of these losses, based on the average soybean price in the 2019/2020 harvest. The results point to the need to adopt preventive measures, such as the review of harvesters before harvesting, to mitigate the negative impact of losses on soybean grain production in the Northwest Region of Rio Grande do Sul.