Sampling intensity and size to evaluate harvest losses in soybean crops

ABSTRACT Proper sampling of grain losses during harvesting operations, with reliable and efficient sizing of sample, is necessary for an efficient adjustment of the harvester to avoid harvest losses. Thus, the objective of this study was to estimate sampling intensity and sample size for harvest loss evaluations in soybean crops. Sampling was carried out in five locations with soybean crops, evaluating three different harvesters. Harvest losses were measured using square wooden frames (50 × 50 cm), which were arranged on the ground longitudinally across the harvester header width after its passage; this process was repeated 25 times at each location. The greatest harvester header width in Location 1 enabled to simulate different sample sizes for this location (50 × 100, 50 × 150, 50 × 200, and 50 × 250 cm). Only one sample size (50 × 100 cm) was used for the simulations in the other locations. Sampling only half the harvester header width is recommended to estimate harvest losses when using 62-foot harvester header, whereas 12.5- and 17-foot harvester headers requires sampling across the entire harvester header width, with a semi-amplitude of the confidence interval of 20% of the mean for all harvesters.

摘要 在收获作业中对谷物损失开展合理取样，并可靠且高效地确定样本规模，是实现联合收割机高效调整、规避收获损失的必要前提。因此，本研究旨在估算大豆作物收获损失评估所需的取样强度（sampling intensity）与样本量（sample size）。本研究在5个大豆种植田块开展取样工作，对3台不同型号的联合收割机进行测试评估。采用50×50 cm的方形木框测量收获损失：在联合收割机驶过作业区域后，将木框沿纵向横跨联合收割机割台（harvester header）宽度布置在地面；每个田块重复该操作25次。由于1号田块的联合收割机割台宽度最大，因此可在该田块模拟多种样本尺寸（50×100 cm、50×150 cm、50×200 cm及50×250 cm）；其余田块的模拟仅采用50×100 cm的样本尺寸。对于配备62英尺割台的联合收割机，建议仅取样割台宽度的一半以估算收获损失；而配备12.5英尺和17英尺割台的机型，则需对整个割台宽度进行取样，且所有机型的置信区间（confidence interval）半幅为平均值的20%。