To enhance the accuracy of an impact-based yield sensor installed inside the grain tank of a combine, we measured the individual impacts of intermittent grain flow accelerated by an auger blade. Non-linear calibration was modeled to relate each impulse received by the sensor to the weight of grain released at a single rotation of the auger blade, taking into account the rotational speed of the auger. The parameters were optimized through pairs of signal recording and grain weight at harvest in situ. The relative error of calibration was less than 2%. The proposed instrumentation and signal processing showed robustness to the flow rate of grain, and the maximum relative error of validation was 3.5%.
A mobile grading machine for citrus fruits has been developed to collect crop information such as fruit yield, diameter, and sugar content of fruits of each tree part. It consists of a mobile mechanism, a differential global positioning system, a fruit conveyer system, a color camera for machine vision, a NIR spectrometer, and a personal computer for control and database. Preliminary field tests were conducted to investigate basic performance of this machine in a mandarin orange orchard. Using the collecting data of fruit yield and diameter and sugar content of fruit, crop information maps of each tree part was made. These maps indicated that each tree part has large variability of yield, size, and sugar content of fruit.
Japanese blue honeysuckle (haskap) is the earliest fresh fruit harvested in Hokkaido starting in late June. In Japan's small-scale orchards, farmers carefully harvest haskap berries by hand so as to avoid losing any juice from the delicate peel. To improve harvesting efficiency with minimal additional cost, we developed new methods employed either plastic pipe or jigsaw for separating the fruit, converted umbrella, plastic net or light pipe with tarp for collecting, and used electric fan or mesh net with water for cleaning. After testing various combinations of separating, collecting and cleaning methods, the harvesting rate was increased from 1.45 kg/h (conventional hand picking) to a maximum 10.36 kg/h. Therefore, it is possible to improve haskap harvesting efficiency at low cost.
A method was investigated for improvement of salt-affected soils in regions where a sufficient amount of rainfall to percolate into subsoil occurs in summer. A coarse layer is provided in the subsoil by deep tillage, making soil clods to cut off the capillary rise from groundwater. This paper deals with plot test fields constructed by hand in a saline soil (solonchak) region. The results showed that the deep tillage to the subsoil was beneficial for the improvement of the solonchak soil. Where the Ap horizon (topsoil) alone was tilled, the vegetation was poor because the capillary rise was not perfectly cut off. Reduction of the pH from about 9.5 to 8.5 was obtained. The EC value decreased from about 0.5 dSm−1 to 0.2 dSm-1. From these results, we determined that the tillage should be deeper to intercept the capillary rise at the subsoil.
A method was investigated for improvement of salt-affected soils in regions where a sufficient amount of rainfall to percolate into subsoil occurs in summer. A coarse layer is provided in the subsoil by deep tillage, making soil clods to cut off the capillary rise from groundwater. This paper deals with plot test fields constructed by hand in a local spot of a sodic soil (solonetz) region. The results showed that deep tillage up to the subsoil (C horizon) was beneficial for improvement of the solonetz soil. Application of the gypsum also reclaimed the solonetz soil, and should be mixed into the A horizon. The pH values decreased from about 10 to 9. The EC values decreased from about 8 dSm −1 to 2 dSm-1.
In order to separate haskaop berries from other materials during harvest by vacuum suction, a vertical separation column was built where specific weight separation would take place. The results showed that the most suitable configuration of the separation column without damage to berries was one with an inlet pipe through the berry bin. This generated vertical air flow throughout the separation column. Thus, leaves were always suspended in the column. When berries entered the column, air velocity decreased, and berries fell into the berry bin. The required air velocity in the transportation pipe was more than 22 ms −1 to move the heaviest berries. The required air velocity in the separation column was more than 4 ms-1 where the heaviest leaves could remain aloft and be separated from the berries.