Detecção precoce da perda de matéria seca da soja armazenada em silos verticais

Abstract

Abstract: soybean (Glycine max L.) is an oilseed rich in proteins, fibers, vitamins and minerals, with high added value in the industry and essential for human and animal nutrition. After harvesting, the soybeans undergo a pre-cleaning stage, in which impurities and undesirable residues are removed. Some of these residues are often not completely removed, which can intensify the respiration of the grain mass during storage. Thus, the objective of the study was to understand the behavior and the influence of residues and damaged soybeans on the respiratory process of the grain mass for early detection of dry matter loss through the monitoring of indirect variables over the storage time. For this, experimentally batches with different percentages of impurities, broken and fragmented grains mixed with the mass of whole grains. The experiment comprised three treatments: Lot R1 (Silo 1) - 100% whole grains, Lot R2 (Silo 2) - 94.8% whole grains, 2.3% fragmented grains, 2.5% broken grains and 0 .4% of impurities, and Lot R3 (Silo 3) - 100% of residues + impurities. CO2 sensors were installed in the upper inner part of each storage silo to monitor the CO2 concentration over the storage time. The temperature of the grain mass was monitored at three points (lower, middle and upper) of the prototype storage silo, with the aid of a mercury thermometer. Also, the temperature and relative humidity of the ambient air, the relative humidity of the intergranular air with the aid of a digital thermohygrometer. With these variables obtained, the hygroscopic equilibrium moisture was calculated and the dry matter loss of the stored grain mass was determined. In the results obtained, it was found that the behavior of the materials stored in prototypes 1 and 2 were similar. The percentages of residues and damage present in the mass of soybeans disposed in Silo 2 did not significantly influence respiration, showing similar values to the grains stored in Silo 1. variations in the monitored variables, providing changes in the hygroscopic equilibrium moisture and consequently an increase in the metabolic activity of the grains. The monitoring of CO2 concentrations, temperature and relative humidity of the intergranular air were effective for early detection of deterioration and loss of dry matter of grains, which can be an important measure for decision making regarding the storage time of soybeans.