Yield of Crops and Productivity of Grain-Beet Crop Rotation in Russia’s Central Black-Earth Region with Long-Term Application of Fertilizers

Abstract

The aim of the investigations is to determine the influence of fertilizers’ application during a long period (from 1936 to 2017) on yield of crops and productivity of the grain-arable crop rotation under conditions of the forest-steppe of the Central Black Earth Region. The object of the investigations is yield of a main crop product in a grain-beet crop rotation (sugar beet, winter wheat, barley, oats, clover). Application of fertilizers in the long-term experiment (from 1936 to 2017) revealed that prolongation of fertilizers’ period of use considerably increased their total efficiency. With direct effect of fertilizers, the average yield for nine rotations of sugar beet roots increased by 21.6–31.9%. After-effect of fertilizers was the greatest for barley, whose average yield increased by 18.4–36.4% in comparison with the control over the period under investigation. Oats and clover showed the least response (10.1–18.4 and 12.7–18.2%, accordingly). For direct effect and after-effect of fertilizers, the best dose of fertilizers was N135P135K135 for sugar beets + 25 t/hectare of manure. In a crop rotation, barley and clover demonstrated the most rapid after-effect (15 years), while winter wheat showed the slowest (40 years). The direct effect of fertilizers for sugar beet was the greatest after 45 years. Between the I and IX rotations, increase in yield (by 7.80–50.4%) and crop rotation productivity (by 10.9–25.4%) for most of the crops was noted; the system N135P135K135 + 25 t/hectare of manure had the greatest positive influence.