winter wheat yield and soil properties response to long-term non-inversion tillage

the studies carried out over 2010-13 involved a static field experiment initiated in 1999 at brody research station of the poznan university of life science, poland. the soil tillage systems for winter wheat were compared on a soil classified as albic luvisols. the aim of experiments was to evaluate impact of ploughless soil tillage on some soil physical, chemical, biological properties and winter wheat productivity parameters. tillage systems included: conventional tillage based on moulboard ploughing (ct), reduced tillage with a stubble cultivator (rt), and no-tillage (nt). the soil tilled under rt and nt recorded higher values of water content and soil bulk density, especially in the top layer. on the other hand, in the 10-20 cm layer, soil bulk density was significantly higher under ct than under rt and nt. soil penetration resistance was lower under ct than under rt and nt from 0 to 20 cm depth. however, soil penetration resistance was consistently higher under ct than under rt and nt from 21 cm to 30 cm depth. organic c and nutrient elements tended to accumulate in the surface horizons under rt and nt compared with ct. enzymatic activities were found in the more superficial layers of soil under rt and nt than under ct. the grain yield decreased by 6.9% under nt compared to ct, and ranged over a similar level under rt and ct. the decreased yield in nt probably resulted primarily from a lower number of ears per unit area. in our opinion, in the future, more research is needed to determine the role of changing soil properties over time in crop yields, and no-tillage system needs to be improved to secure plant establishment and crop yield.