Influence of Weather Conditions in the Stavropol Territory in Efficiency of Doses of Nitrogen Fertilizer on Corn
In the field experiment on the ordinary black soil of a sufficient moistening zone of Stavropol region, the effect of different doses of nitrogen fertilizers (N30–120) on the grain yield of the early-maturing corn hybrid Mashuk 185 MV was studied. A linear correlation was established between precipitation and hydrothermic coefficient in June-August and yield increase of corn grain from nitrogen fertilizers. It was revealed that the dependence of yield growth from fertilizers is determined not only by precipitations amount, but also by the nitrogen dose. Thus, the correlation coefficients between precipitations in June, July, the periods June–July, June–August and grain yield increase were: while applying the dose of N30 from 0.67 to 0.79, N60 – 0.73–0.82, N90 – 0.78–0.92, N120 – 0.87–0.90. Precipitations in July were crucial for obtaining the greatest increase in grain yield when following nitrogen doses N60–120 was applied (r = 0.78–0.90). Precipitations in June and July had an average effect (r = 0.67) when dose of fertilizer N30 was applied. A strong linear correlation between hydrothermic coefficient in June, July, the periods June–July, June–August and grain yield increase was observed when apllying doses N90 (r = 0.89, 0.71, 0.90) and N120 (r = 0.85, 0.72, 0.87).