Influence of Decadal Atmospheric Moisture on Spring Wheat Yield in the Forest-Steppe Zone of Novosibirsk Oblast
In the period 1960–2017 (May to September) in the forest-steppe zone of the South-East of Western Siberia, there is a significant increase in air temperature in the third decade of August and the first decade of September, and a decrease in atmospheric precipitation in the first decades of June and August. To characterize the intensity of droughts and atmospheric waterlogging, the Ped drought index (<i>Si</i>) was calculated. In years with high and low yields, excessively humid conditions (<i>Si</i> < –1.1) were observed for two or three decades, droughts of varying intensity (<i>Si</i> > 1.1) – for two or four decades. Yields above 16.5 c/ha were observed with excessive atmospheric humidification in the third decade of June and the first decade of July; less than 6.4 c/ha—with an increase in aridity in the first decade of May, June, the first and second decades of August. The analysis of linear trends made it possible to determine the general trend of change in the yield of spring wheat in the study area (+0.7 c/ha/10 years). Regression analysis between decadal anomalies of atmospheric humidification and yield of spring wheat was carried out. The closest links are between spring wheat yields and drought of varying intensity in the first decade of May, the first and second decades of August.