[Soil physical properties and its effects on wheat yield in typical dark loessial soil on Weibei Plateau, China.]

Based on the investigations of fertilizer application rates, wheat yield and soil properties (soil compaction) of dark loessial soil on Weibei Plateau in 2015, soil samples from 0-50 cm depth were collected in 61 winter wheat fields. The variability of soil compaction, bulk density, water-stable aggregates and their partial correlations with wheat yield and partial factor productivity were analyzed. The results showed that soil compaction and water-stable aggregates in 0-50 cm depth had weak variability, with the variation coefficients of 9.9% and 4.9%, respectively. Soil bulk density had moderate variability, with the variation coefficient of 27.5%. Wheat yield and fertilizer partial factor productivity were negatively correlated with soil compaction, which were more closely correlated in soil depths of 0-10 cm, 10-20 cm and 20-35 cm. Results from multiple regression showed that wheat yield was determined by soil compaction and organic matter. The improvement of soil organic matter and reduction of soil compaction in top soil (0-20 cm) and plough pan layer (20-35 cm) would be the key strategies to enhance wheat yield in dark loessial soil on Weibei Plateau.