Effect of different tillage methods and seed rate on quantitative and qualitative yield of wheat cultivars in a wheat – fallow rotation system in cold area of rainfed condition

The effect of tillage methods on the quantitative and qualitative yield of rainfed wheat cultivars in different seed rates under a fallow-wheat rotation system during three cropping seasons (2017-1999 to 2009-2010) at Saral Research Station was studied. A strip split plot design based on RCBD with three replications was used. Conventional Tillage, CT(tillage with moldboard in spring followed by disk harrow in summer), Minimum Tillage, MT(Stubble cultivator after harvesting in summer) and No Tillage, NT(direct planting without soil disturbance) as horizontal, rainfed wheat cultivars(Azar 2, Baran and Sardari) as vertical and different seed rates(300, 350, 400 and 450 seeds per square meter) were considered as subplots. The results showed CT compares with MT and NT, increased grain yield by 22% and 21%, respectively. Wheat cultivars did not affect grain yield, significantly. The seed rate of 350 grain per square meter produced more grain yield than other treatments. Apart from the interaction of year × tillage, none of the interactions were significant. There was no significant difference between cultivars and seed rate in terms of protein percentage, but the effect of tillage was significant at 1% level, so that the highest and the lowest amount of grain protein was found in CT(12.72%) and MT (11.59%), respectively. The response of wheat cultivars to seed rate and tillage in the wheat-fallow system was not significantly differed. Due to the long fallow period and the reduction of residues on the soil surface followed by sharp decline in yield, conservation tillage is not recommended.