This research was aimed to identify the most suitable tillage systems for sustainable winter wheat ( Triticum aestivum L.) yield levels, with best economic efficiency, assuring at the same time high quality soil physical and mechanical properties. The field experiments were carried out at Fundulea on a cambic chernozem soil type. Four tillage systems were tested to determine their influence on soil water content, soil macro-aggregates, resistance to soil penetration, wheat grain yield and its components, and crop economic efficiency. The following tillage systems were studied: traditional, with moldboard plough (TS); chisel plough tillage - primary tillage executed with chisel implement type without furrow over throwing (CS); disc/sweep tillage, providing a combined effect of vegetal remnants chopped with disc implements along with soil work with arrow type tools, without furrow over throwing (DS); No till (NT) - without any tillage work. In comparison with TS variant, soil conservation tillage systems (SCTS), as CS, DS and NT, increased the soil water content, recorded at seeding time, with 0.8%, 3.9%, and 4.1%, respectively. Soil water content, recorded at harvest time for CS and NT variants was 1.3% and 2.5% higher than in the case of TS (P2 mm with 5.5%, and the mean weighted diameter of soil particles resulted by dry sieving, with 5.5% and 10%, respectively. Yield components recorded for soil conservation tillage systems (CS, DS, and NT) did not differ significantly from those evaluated for traditional system (TS), but the superior values of 1000 kernels weight and spike density suggest that these components contributed more to higher yields, obtained with SCTS, than grain weight per spike, number of grain per spike, and number of grains per square meter. With regards to economic efficiency, the outputs of all tested SCTS were significantly greater than the TS. The present study, revealing important advantages of soil conservation tillage systems over the traditional one, revealing the improvement of soil physical and mechanical properties, higher winter wheat yield levels and higher crop economic efficiency, invites farmers from South Plain of Romania to adopt soon these new progressive systems.
