Yield Dynamics in Permanent Crops of Peas and Potatoes in Long-Term Field Experiments on Chernozems of the Kursk Region

The data of 44-year field experiments with permanent crops of peas and potatoes in the chernozems of the Kursk Oblast are analyzed. Long-term trends in the yield of pea grains and potato tubers were significantly decreasing with reaching consistently low levels. The possibility of a correlation between a decreasing trend in yield and a decreasing trend in solar activity over the same time period is shown. The decrease in yield was accompanied by significant cyclical fluctuations with a period of mainly approximately 7 years. It is shown that this cycle duration is close to the cycles of weather conditions in a given area. The long-term yield dynamics of the variants significantly differed from each other according to the algorithm of conjugate samples. At the same time, the average long-term yields for the entire period of the experiment only for the control potato variant differed significantly from the variants with fertilizers. A preliminary conclusion was made that, given the nature of the temporal dynamics of yields, the second approach to comparing options turned out to be more crude than the first.