The study was conducted to determine the influence of preceding crop, mineral fertilizers, and weather conditions on the formation of spring wheat agrophytocenosis grown according to no-tillage technology. The object of the study was weed component of agrophytocenoses and its influence on spring wheat productivity in the northern forest-steppe zone of the Southern Urals in conditions of no-tillage. The experimental design comprised three crop rotation types and a monoculture with six spring wheat predecessors without fertilizers and with application of nitrogen fertilizers. Under no-tillage technology, the weed component in spring wheat crops in all the experimental types of treatment consisted of annual weeds. Their numbers in different types of crop rotation considerably depended on weather conditions; when the weather was wet, the average difference between the preceding crops reached 27 plants/m2, with variation coefficient of 47%. Spring wheat biomass significantly depended on fertilization levels—average differences over years reached 722 g/m2. The (pea + oats) precursor showed a higher biomass of annual weeds than other predecessors, average by 43–662 g/m2 for both fertilization levels. Specific weight of weeds in the total biomass of the agrophytocenosis significantly depended on meteorological conditions, with differences amounting to 7%. In dry years, the influence of annual weed abundance and crop biomass on spring wheat productivity in a fertilized environment reached 80–82%.
Shatalina et al. (Sun,) studied this question.