Abstract:Abstract: Soil tillage is closely related to creating favorable conditions for crop growth and ensuring crop yield. One of the main goals of soil tillage is influencing the physical, chemical and biological properties of soil. One of the basic soil properties affected by tillage is the soil compaction. The objective of this work was to evaluate the effects of no tillage (NT), plow tillage (PT), spacing tillage (ST) and conventional tillage (CT) on the soil compaction from annual and seasonal changes, soil profile characteristics and seasonal freezing-thawing for a productive soil. The field experiment was initiated in Gongzhuling County, Jilin Province in 1983, which was to determine the effects of various rotation and tillage combinations on crop yield and soil physical and chemical properties. The soil of the experimental site was silt loam, which was well-drained soil developed mainly from glacial tillage. The experiment design was a completely random block design with 3 replications. The plot was 150 m long and 8 m wide (1 200 m2). We measured the soil compaction change in different years and seasons with SC-900 soil compaction meter. The results showed that no tillage increased the soil compaction in 0-25 cm depth significantly(P<0.05) compared with other tillage methods, and decreased the soil compaction in 25-45 cm depth significantly(P<0.05) while conventional tillage increased the soil compaction in the depth of 25-45 cm. The soil compaction by spacing tillage and plow tillage were lower than no tillage and conventional tillage significantly(P<0.05). The soil compaction of different tillage methods changed with different seasonal periods, the change trends of 0-25 and 25-45 cm were the same, and the soil compaction on August 10th was higher than other dates. The soil compaction of different tillage methods increased with the increase of soil depth, which meant the soil compaction of upper layer was less than lower layer significantly(P<0.05). The profiles with different tillage methods changed with time. The change of soil compaction showed a linear increase with the depth under 20 cm in the early stage of crop growth, and the change was like reverse "S" shape in the mid-to-late stage of crop growth. The freezing-thawing decreased the soil compaction of different tillage methods significantly(P<0.05). The decline of soil compaction was 148.97%, 41.96%, 58.44% and 3.38% under spacing tillage, no tillage, plow tillage and conventional tillage, individually. So, spacing tillage was an effective tillage method for decreasing the soil compaction. The adoption of spacing tillage in the semi-humid zone of Jilin Province could be beneficial to soil conservation by decreasing soil compaction, controlling erosion and improving soil structure, et al. Our study can be helpful to the promotion of the new tillage technology in northeast China for developing the sustainable agriculture.