Study the soil physical properties and some wheat cultivars grain yield under different tillage systems

The aim of study was to determine the effect of tillage systems on soil moisture, soil properties and grain yield of irrigated wheat. this experiment was carried out using RCBD in split-plot arrangement including 9 treatments and 4 replicates. The studied soil related physical parameters were volumetric moisture content (VMC), bulk density (BD) and soil porosity (SP) along with the grain yield of irrigated wheat genotypes. The treatments consisted of tillage systems in three levels related to conventional, reduced and no-till methods as main plots and three wheat cultivars of Pishtaz, Pishgam and Bahar as sub-plots. According to ANOVA results main plots effect on BD in 0-15 cm top soil layer was significant (P<0.01), and conventional method had the minimum BD, while BD increased in 15-30 cm soil layer, but its amount was less in conventional method comparing to other tillage treatments. Main plots treatment had significant effect on SP and its largest measured amount (57/71%) was observed in 0-15 cm soil layer related to conventional method and the smallest amount of SP (43.9%) was measured in no-till method. Based on the results, measured VMC in 2nd and 5th days after irrigation in wheat log-phase growth stage were 0.63 and 0.34 g cm-3 in conventional and no-till methods, respectively. In the interaction between tillage systems and wheat cultivars, the overall grain yield of Pishtaz cultivar in conventional tillage (5833) was significantly higher than the other two methods (P<0.01) on the other hand the mean grain yield of Pishgam cultivar (5045), (4023) kg/ha was significantly higher than the other two cultivars in no-tillage and minimum tillage respectively compared to the conventional tillage (P<0.01).