Integrative impacts of rotational tillage on wheat yield and dry matter accumulation under corn-wheat cropping system

Significant efforts have been made on the assessment of tillage impacts on crop growth during the current season; however, few studies have quantified the impacts on the succeeding crop growth under multiple cropping systems. Based on a multiple-year field experiment under corn-wheat cropping system in North China Plain, therefore, we examined the integrative impacts of annual rotational tillage on wheat growth and soil properties. The annual rotational tillage treatments consisted of two tillage regimes (i.e. N: no-tillage; and SR: sub-soiling with rotary tillage) in the corn season followed by three tillage practices (i.e. sTR: strip rotary tillage; R: rotary tillage; and SR: sub-soiling with rotary tillage) in the wheat season, respectively. The results showed that the N SR rotational tillage of N in the corn season and SR in the wheat season significantly reduced soil penetration resistance and promoted soil water usage of 60-100 cm soil layers during wheat season. Meanwhile, soil NO3--N concentration in the depth of 40-140 cm was significantly lower under the N-SR than other tillage practices except for the N-R (P < 0.01). Average results of two-year dry matter accumulation and translocation showed that N-SR stimulated wheat biomass production and promoted the contribution of post-anthesis dry matter to the grain (P < 0.01). Consequently, wheat yield was the highest under the N-SR (P < 0.01). Our findings indicate that the annual rotational tillage of no-tillage in the corn season and sub-soiling with rotary tillage in the wheat season can promote wheat growth through enhancing deep soil water and N uptake.