Grain yields of winter wheat (Triticum aestivum L.), maize ( Zea mays L.), and soybean [ Glycine max. (L.) Merr], in rotation were significantly influenced by soil deep loosening and tillage system, depending on water supply (irrigation application). Scientific literature regarding the influence of these agronomic factors on the yield quality of the respective three crops, in rotation, is quite limited. For this study, a field experiment was carried out at Fundulea, which is located in the eastern part of the Danube Plain, on a cambic chernozem soil type. One of the main objectives was to determine how the grain yield quality of winter wheat, maize and soybean is influenced by different reduced tillage systems, in comparison with the traditional (conventional) one, as well as by the direct seeding in non-worked ground, or in strip till, with and without soil deep loosing, under different irrigations. Regarding the maize, the water provisioning * tillage system interaction was very significant (P0.05). Under the three water provisions applied, protein content had values between 40.0%, recorded when the normal irrigation rate was used, at no till system, and 41.5%, recorded for the dry conditions, also at no till system. The 1,000 kernel weight varied between 120 g, registered for the dry conditions at no till variant, and 159 g, registered for normal irrigation rate, also at no till system. The results of this research do not make evident a certain tendency of protein content, but show clearly that the fat content increases concomitantly with grain yield growing. As concerns the winter wheat crop, the water provisioning * tillage system interaction was not significant (P>0.05). Protein content was comprised between 13.2%, registered when the normal irrigation rate was applied at no till system variant, and 15.7%, under dry conditions, at the traditional tillage system. The minimum value of 1,000 kernel weight was 37 g, recorded for dry conditions at chisel tillage variant, and the highest value, of 47 g, was obtained when normal irrigation rate was applied to no till variant.
