Effect of crop rotation and fertilization of sugar beet on the formation of maximum bioethanol yield

Abstract

The purpose of research is to evaluate the efficiency of growing sugar beet for bioethanol as affected by a fertilization system, tillage, and soil moisture zone. The study was conducted in the Forest-Steppe of Ukraine under the conditions of insufficient and unstable soil moisture. It was found that growing sugar beet for bioethanol should be aimed at increasing their productivity through the practicing of organic- mineral fertilization and using cattle manure or straw. For the cultivation of sugar beet, the most effective are those crop rotation units that contain legumes or, if insufficient soil moisture, the units which include bare fallow. It was found that in the area of insufficient soil moisture, fertilization factor determined bioethanol yield by 44 %, while in the zone of unstable moisture by 55%. At the same time, in the area of insufficient soil moisture, the effect of crop rotation unit increases as a factor ensuring a sufficient level of soil moisture available to the plants (26%), and in the area of unstable soil moisture, these factors affect bioethanol yield by only 19 %. By analogy, the weather factor in the insufficient soil moisture zone has a greater effect on bioethanol yield (20%) than in the unstable soil moisture zone (14%). In addition, the total impact of a crop rotation unit and weather conditions in the area of insufficient soil moisture is higher than fertilization treatment. Sugar beets, under the conditions of insufficient soil moisture, provide a yield level high enough to produce 3.18 t/ha of bioethanol at the production cost of $ 0.40 per litre, while for growing maize bioethanol yield will be 1.41 t/ha at the production cost of $ 0.59 per litre. Under the conditions of unstable soil moisture, bioethanol yield per unit area of maize grows to 2.45 t/ha; however, this crop cannot be compared to sugar beet in terms of efficiency, although production costs are approximately equal. By applying a sufficient package of agronomic practices, it is possible to obtain a sufficiently high yield of bioethanol from sugar beet roots, even under the conditions of insufficient soil moisture. To optimize sugar beet nutrition under the conditions of insufficient soil moisture it is recommended to incorporate post-harvest straw residues over the background of N140P90K90, and under the conditions of unstable soil moisture to apply 50 t/ha of manure + N100P100K100.