Effects of tillage managements, sowing depth and soil-covering on population quality and yield of mechanical sowing wheat under relay intercropping condition

In order to research the corresponding agricultural measures of intercropping wheat mechanical sowing technology in hill areas, the effects of two different tillage managements (tillage, no-tillage), three sowing depth (2 cm, 5 cm, 8 cm) and soil-covering (no-soil-covering was CK) on population quality and yield were investigated. The results indicated that the magnitude order of the three agricultural measures was sowing depth>tillage managements> soil-covering. Population quality and yield index were positively correlated with sowing depth, and the optimal depth was 5, 8 cm the second. At 2 cm, tillers number and population size was small, and spike formation mainly depend on the main stem, furthermore, dry matter accumulation, LAI and yield significantly decreased. No-tillage treatment was better than tillage treatment. population size was enlarged by no-tillage treatment, what’s more, post-anthesis dry matter accumulation, spike number, spike rate and yield significant increased. With soil-covering treatment, tillers number and post-anthesis dry matter accumulation increased, and that resulted in higher yield. In addition, the interaction effect of the three agricultural measures was significant. As far as the agricultural measures of intercropping wheat mechanical sowing in hill country is concerned, no-tillage, the 5 cm sowing depth and soil-covering are recommended to improve population quality and increase whole yield level.