Effect of soil compaction on early soybean plant growth in sandy loam Manitoba soil

Sandy loam Manitoba soil was subjected to different levels of soil compaction to determine its effect on early growth of soybean plants. Soybean seeds were planted within finite containers of soil samples and were subjected to low, medium and high compaction treatments as well as a no compaction control treatment. Factors affecting plant growth such as room temperature, relative humidity, initial moisture, initial bulk density, and soil surface strength were measured experimentally. There was a significant difference in soil surface strength (P<0.0001), but not in bulk density across compaction treatments (P=0.2000). The increased soil surface strength of the high compaction treatment, which had a mean compaction effort of 17.25 kJ m -3 (SD=4.15), corresponded with a soil compaction layer that was more difficult to overcome, resulting in 25% of seedlings not emerging in the two-week observation period. The delay in seedling emergence for low, medium, and high compaction seedlings caused significant differences between the plant heights of the control and the compacted soil samples. However, there was not a significant difference in leaf count per container across compaction treatments. A limitation of this study was the use of finite containers, which resulted in compaction that differed from that present in field conditions.