ECONOMIC EFFICIENCY OF NON-CONVENTIONAL SOIL TILLAGE SYSTEMS IN SOYBEAN AND BARLEY PRODUCTION

Short-term study of non-conventional soil tillage systems was conducted at the experimental field near Staro Petrovo Selo (45 degrees 10' N, 17 degrees 30' E) on hypogleyvertic type of soil and semi humid climate conditions. The tillage systems and implements used were: CT - mouldboard plough, disc harrow, seed-bed implement, drill, RT 1 - chisel plough, disc harrow, seed-bed implement, drill, RT 2 - chisel plough, rotary harrow integrated with seed drill, RT 3 - mouldboard plough, rotary harrow integrated with seed drill, RT 4 - chisel plough, mouldboard plough, rotary harrow integrated with seed drill. The weather conditions had great influence on production of soybean and spring barley, and the occurrence of drought periods during the vegetation season could have affect the yields. The highest average yields were obtained by RT 1 system in soybean (3.78 t ha(-1)) and RT 2 in barley production (3.20 t ha(-1)). The greatest energy and labour savings in soil tillage, among the lowest total cost of production, were achieved by RT 2 system, but due to the significantly lower yields this system has not proved adequate for soybean production. The highest economic efficiency of soybean production has shown RT 1 system (coefficient of 2.16), while in barley production the most profitable system was RT 2 (coefficient of 1.81). Regarding the choice of tillage systems, assuming uniform level of yields, the advantage should be given to systems with lower level of tillage intensity, not only to reduce costs but also because of the possibility of simpler production organization due to less machine and labour requirement.